Posters 10-18
10. Inflammation and Inflammatory Disorders
(10-1) N-3 PUFAS REDUCE INFLAMMATION AND DEGRADATION IN IN VITRO MODELS OF
ARTHRITIS
Katrina Duggan, Andrea J. Longman, Samantha Hurst, Clare L. Curtis, Bruce Caterson, Simon A. Jones, John. L. Harwood, School of Biosciences, P.O. Box 911, Cardiff, UK
Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) have been widely used to treat a variety of inflammatory conditions
including osteoarthritis (OA) . Previous work in our laboratory has utilised bovine articular cartilage explants to study
the effects of n-3 PUFAs derived from fish oils (eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) on arthritis. We are continuing this work utilising EPA and DHA in a dose- and time-response study of an induced
arthritic state. The effects of explants supplemented with various n3/n6 (EPA or DHA:Arachidonic Acid) combinations have also been studied in order to determine an appropriate ratio for maximal effect. PUFA was added to the cartilage
in culture medium at 10, 25, 50 or 100 µg/ml or 25:75, 50:50 or 75:25 µg/ml n3:n6 for the combination studies. Cartilage degradation was initiated by the addition of the pro-inflammatory cytokines IL-1α or TNF-α to the cartilage
explants in fresh medium with incubation for 72 hours. To measure time response, the n-3 PUFAs were supplemented to the growth media of the explants for a period of between 1 and 8 hours before the addition of cytokine. Response of
the cartilage explants to the treatment was measured by quantitative PCR . Primers used include those for cartilage components (e.g., aggrecan), the pro-inflammatory cytokines TNF-α and IL-1β, the enzymes involved in cartilage measured.
Supported by BBSRC grant 72/D16961
(10-2) EFFECT OF FISH OIL SUPPLEMENTATION ON CYTOKINE PRODUCTION BY PBMCs OF
PATIENTS WITH PERIPHERAL VASCULAR DISEASE (PVD)
J.Madden1, J. Hadley 1, N.Dastur 1, N.T.Luu 2, E.Rainger 2, G.Nash 2, C.Shearman 1, W.M.Howell 1, P.C.Calder 1, R.F.Grimble 1 1 School of Medicine, University of Southampton, UK 2 University of Birmingham Medical School, Birmingham, UK
Fish oil reduces the risk of cardiovascular disease and re-infarction. Inflammation plays an important role in atherosclerosis. The effect of fish oil on pro- and anti-inflammatory cytokine production in patients with severe
atherosclerosis is unknown.Male patients (27) with PVD and healthy male controls (64) were given 6g/d MaxEPA for 12 weeks. Blood samples were taken pre- and post- supplementation. PBMCs were cultured in RPMI containing 5%
autologous plasma and 10ug/ml LPS for 24h. TNF-α, IL-1β, IL-6, and IL-10 were measured in medium by ELISA. IL-6 was greater in patients than controls pre-supplementation (11.60±6.56 vs 8.60±4.90 ng/ml ; p=0.027 Mann-Whitney
test ). While mean values of TNF-α production were lower in both groups after fish oil ( 0.84±1.34 vs 0.64±0.44 controls; 1.08±1.09 vs 0.88±0.77 patients) the effect was not significantly (paired ‘t’ test). Data from controls was
divided into an upper (A) and lower (B) groups for initial TNF-α production . In group (A) fish oil significantly reduced TNF-α and IL-1β production (p=0.049 and 0.028 respectively), TNF before vs after 1.38±1.74 vs 0.74±0.54 ; IL-1α
3.07±2.24 vs 2.22±1.51). Higher IL-6 production indicates raised inflammatory stress in PVD. While fish oil exerts no significant effect on pro-inflammatory cytokine production in PVD mean values indicate that with increased patient
numbers the change may reach significance. We are grateful to the BBSRC for financial support and to Seven Seas Ltd for the gift of fish oil capsules.
(10-3)
BLOOD MONONUCLEAR CELLS AND PLATELETS HAVE ABNORMAL FATTY ACID COMPOSITION IN PATIENTS WITH HOMOZYGOUS SICKLE CELL DISEASE
Hongmei Ren1, Iheanyi Okpala2, Kebreab Ghebremeskel1, Cynthia C. Ugochukwu2, Okike Ibegbulam3, Michael Crawford1, 1IBCHN, London Metropolitan University; 2 St. Thomas’ Hospital; London; 3University of Nigeria Teaching Hospital, Enugu
Leukocyte adhesion to vascular endothelium contributes to blood vessel occlusion – the cause of widespread organ damage and malfunction in sickle cell disease (SCD). Previously, we found high expression of the adhesion molecules αΜβ2 integrin and L-selectin by leukocytes in homozygous (HbSS) patients with severe manifestations of SCD. Since membrane polyunsaturated fatty acids modulate expression of cell adhesion molecules; and are vital for inflammation,
membrane lipid asymmetry and fluidity, we have investigated the fatty acid composition of mononuclear cells (MNC) and platelets of HbSS patients (n=28) and racially-matched, healthy HbAA controls (n=9). The MNC phospholipids of
the patients had lower levels of docosahexaenoic (DHA, P<0.05) and total ω-3 fatty acids (P<0.05). In contrast, arachidonic (AA, P<0.01) and ω-6 metabolites (P<0.05) were higher in the patients. In the platelets, the patients had
lower eicosapentaenoic (EPA, P<0.05) and DHA (P<0.05) and higher AA (P<0.01) in choline phosphoglycerides, and lower DHA (P<0.05) in ethanolamine phosphoglycerides. The results suggest that an imbalance between AA, EPA and
DHA, with increased production of aggregatory and pro-inflammatory eicosanoids may activate platelets and
leukocytes and enhance chronic inflammation, leukocyte adhesion molecule expression and vaso-occlusion in SCD.
(10-4)
HOMOZYGOUS SICKLE CELL DISEASE ENHANCES THE ACCRETION OF ARACHIDONIC, ADRENIC AND DOCOSAPENTAENOIC ACIDS IN RED CELLS
Hongmei Ren1, Obike Ibegbulam3, Iheanyi Okpala2, Kebreab Ghebremeskel1, Cynthia C. Ugochukwu2, Michael Crawford1,1IBCHN, London Metropolitan University; 2 St. Thomas’ Hospital, London; 3University of Nigeria Teaching Hospital, Enugu
Previous studies have indicated that plasma and/or red cell fatty acid perturbation occurs in homozygous sickle cell disease (SCD). In most of these investigations, the numbers of subjects enrolled were small. In addition, only total
lipids or total phospholipids were analysed. We have investigated fatty acid composition of red cell choline (CPG), serine (SPG) and ethanolamine (EPG) phosphoglycerides and sphingomyelin (SPM) of HbSS patients (n=43) and
compared with healthy, racially-matched HbAA controls (n=43). Both groups were recruited from Enugu, Nigeria. The patients had higher levels of adrenic and docosapentaenoic (DPA, 22:5 ω-6) acids in CPG (P<0.005), EPG (P<0.001),
SPG (P<0.001) and arachidonic acid (AA) in CPG (P<0.001) and EPG (P<0.005) compared to the control group. In addition, the SCD patients had lower linoleic acid (LA) in CPG, EPG, SPG and SPM (P<0.001). Red cell CPG DHA
and EPA and red cell EPG DHA correlated well with haemoglobin in the patients. Both LA and AA were reduced in plasma CPG, triglycerides and cholesterol esters. The data suggest that the synthesis of AA and/or membrane uptake
of LA and AA may be abnormal in SCD. This abnormality may promote erythrocytes adherence to vascular endothelium, vaso-occlusion and tissue damage characteristic of this disorder by altering membrane fluidity and
asymmetry of membrane phospholipids.
(10-5)
LYPRINOL™: A POTENTIAL PREVENTIVE TREATMENT FOR EXPERIMENTAL INFLAMMATORY BOWEL DISEASE (IBD)
D Tenikoff a, K Murphyb, M Lea, R Butlera, G Howartha, P Howeb, aChild Health Res Inst., Womens’ & Childrens’ Hospital, bNutritional Physiology Research Group, Univs of Adelaide & SA, Adelaide, Australia
Stabilised lipid extracts of New Zealand Green Lipped Mussel such as Lyprinol™ (LYP) are considered beneficial in treating arthritis and other inflammatory conditions. It is uncertain, however, whether any benefit is due to their ω3 fatty
acid content. We compared the effect of LYP and fish oil pretreatments on experimental induction of IBD in mice. Male C57BL/6 mice aged 6 weeks were gavaged daily for 13 days with 150µl of olive oil (OO, n=7), LYP (5mg in OO; n=8)
or fish oil (FO, 55mg EPA/DHA; n=8). Mice consumed 2% dextran sulphate sodium (DSS) for 6 days from day 7 to induce colitis. Body weight and disease activity index (DAI) scores were recorded daily; colonic inflammation was
assessed by myeloperoxidase (MPO) activity and histopathologic damage to the ileum and colon. Compared with FO, LYP treated mice had less weight loss during DSS consumption, lower DAI scores, smaller crypt area losses (distal
colon), lower caecum and colon weights (P<0.05) and a trend for lower overall colitis severity in the distal colon (P=0.07). MPO activity was not significantly affected by either LYP or FO vs. OO. These findings indicate that LYP may
be potentially useful in ameliorating symptoms of IBD. The benefit, however, is unlikely to be due to its ω3 content. Dose-response evaluation of LYP in experimental IBD is warranted.
(10-6) COCHRANE SYSTEMATIC REVIEW OF OMEGA-3 FATTY ACIDS (FROM FISH OILS) FOR
CYSTIC FIBROSIS
N. Beckles Willson1, T. Elliott2, M. Everard2,1Department of Nutrition & Dietetics, 2Department of Paediatrics, Sheffield Children’s Hospital, Sheffield, UK
A diet rich in omega-3 essential fatty acids (from fish-oils) may have beneficial anti-inflammatory effects for chronic medical conditions such as Cystic Fibrosis (CF), where pulmonary inflammation is believed responsible for loss of lung
function. Aim of systematic review: Is there evidence that omega-3 essential fatty acid supplementation reduces morbidity and mortality? If so, are there any associated adverse events? Methods: Comprehensive electronic database
searches plus hand-searching conference proceedings were undertaken to identify all randomised controlled trials (RCT), in patients with cystic fibrosis, in which omega-3 fatty acid supplements were compared with placebo oils low in
omega-6 and omega-3 fatty acids. There were no common outcomes so only qualitative analyses were undertaken. Results: Six trials were identified, but only two (n=31) met the inclusion criteria. Both compared omega-3 oils with olive
oil controls for a 6- week treatment period. One study (n=19) showed improved lung function tests and lower sputum volume. Both studies reported that diarrhoea was a problem for some participants (for both fish oil and olive oil control
groups). Conclusions: Insufficient evidence exists for the safety and effectiveness of omega-3 fatty acids in CF. A large, long-term multi-centre RCT is needed to determine if there is a significant therapeutic effect and to assess the
influence of disease severity, dosage and treatment duration.
(10-7)
THE EFFECTS OF N6- AND N3-POLYUNSATURATED FATTY ACIDS ON THE FATTY ACID COMPOSITION OF A MASTOCYTOMA CELL LINE AS A MODEL FOR CANINE
ATOPIC DERMATITIS
Thomas Gueck, Anja Seidel and Herbert Fuhrmann, Institute of Biochemistry, Faculty of Veterinary Medicine, University of Leipzig, Germany
Cutaneous mast cells are considered to take an integral part in the pathogenesis of atopic dermatitis (AD) by releasing inflammatory mediators. Dietary polyunsaturated fatty acids (PUFA) are incorporated in cellular membranes, thereby
influencing mediator release. 40 % of atopic dogs are reported to respond to a dietary intervention with PUFA leading to alleviated symptoms of AD, the reason for that being unsettled. The purpose of our investigation was to examine the
effects of n6- and n3-PUFA on the fatty acid composition of canine mastocytoma cells (C2) as a possible model for AD. C2 were cultured in a basic medium or with the addition of 14µM linoleic (18:2n6; LA), γ-linolenic (18:3n6; GLA),
arachidonic (20:4n6; AA), α-linolenic (18:3n3; LE), eicosapentaenoic (20:5n3; EPA) or docosahexaenoic acid (22:6n3; DHA). After 8 days fatty acid composition was qualified by GC-MS and quantified by GC-FID.
The fatty acids supplemented were enriched in C2. The efficiency of incorporation in % varied widely (EPA 28, LE 35, LA 45, AA 56, DHA 61, GLA 68). In addition, the fatty acids supplied except DHA were extensively converted by
elongation. C18 FA were delta 6-desaturated. However, substantial amounts of fatty acids beyond the delta5- desaturase step were not observed. In addition C22 fatty acids were not elongated measurably. C2 presumably
retroconvert DHA in some degree to EPA. The results let us assume that C2 has no nameable activity of the delta5-desaturase. With respect to the proposed low model for canine AD.
(10-8) PLASMA POLYUNSATURATED FATTY ACID PATTERN IN BEHCET’S DISEASE
Feki M, Sithoum M, Khanfir M, Fekih S, Hamzaoui K, Houman MH, Kaabachi N.,Department of Biochemistry and Department of Internal Medicine, Rabta Hospital, & Department of Histology, Faculty of Medicine
of Tunis, Tunisia
Background: Behcet's disease is a multisystem chronic inflammatory disorder characterized mainly by recurrent oral and genital ulcers, ocular, vascular and neurological lesions. Its pathogenesis is not clear but is presumed to be
multifactoriel, implicating genetic, infectious and immune factors. Polyunsaturated fatty acids (PUFAs) are recognized to modulate immune and inflammatory response and n3 PUFAs have been reported to exert beneficial effects in some
inflammatory and autoimmune diseases. This study was aimed to assess plasma PUFAs pattern in BD patients. Material and methods: This case-control study included 12 patients with BD aged 17 to 49 years (mean 34, 2) and 16
sex- and age-matched healthy controls. Plasma fatty acids pattern of total lipids were determined by capillary column gas-liquid chromatography.
Results: Compared to controls, BD patients showed significantly higher percentages of C20:4 n6 (8.01 ± 1.39 vs 6.42 ± 1.81), C20:5 n3 (0.63 ± 0.25 vs 0.41 ± 0.22) and C22:6 n3 (2.53 ± 0.84 vs 1.32 ± 0.64). The percentage of the other
unsaturated and saturated fatty acids did not differ between patients and controls. The C20:4 n6/C20:5 n3, and n6/ n3 fatty acids ratios were significantly lower in BD patients (13.6 ± 2.4 vs 19.9 ± 11.7 and 11,0 ± 2.2 vs 15.7 ± 4.7,
respectively). Conclusion: Plasma fatty acid profile of BD patients is characterized by increased both n6 and n3 PUFAs and
decreased C20:4 n6/C20:5 n3 and n6/ n3 fatty acid ratios. These results are in discord with the expected proinflammatory status in BD. However, determining leukocyte membrane fatty acid pattern may better reflect the
immuno-modulatory effects of fatty acids.
(10-9) RELATIONSHIP BETWEEN TISSUE EPA LEVELS AND TOOTH RETENTION
Kei Hamazaki1, Miho Itomura1, Tomohito Hamazaki1, Shiro Watanabe1, Shigeki Sawazaki2,1Department of Clinical Sciences, Institute of Natural Medicine and 2First Department of Internal Medicine, School of Medicine,
Toyama Med and Pharm Univ, Toyama, Japan
Periodontitis is responsible for most tooth loss in adult populations. Fish oil has anti-inflammatory effects. Consequently, high tissue levels of n-3 fatty acids may predict tooth retention.
Methods: Two hundred and fifty-six men _41±11 y_and 95 women (39±11y) were recruited from 17 hospitals and companies in Toyama-City. The numbers of their remaining teeth excluding third molars (max=28) were counted. The
fatty acid composition of the total phospholipid fraction from washed RBCs was analyzed by gas chromatography. All subjects were asked about their smoking and drinking status, life-style-related disease and ranks at their work.
Results: The levels of EPA in RBC were 1.73±0.73%. The levels of EPA was positively associated with the number of remaining teeth after adjustment for age and sex (p<0.004) and after further adjustment including ranks at work
(p<0.007). Discussion: Management ability may be related to tooth retention. However, it was considered in this study by
adjustment for ranks of subjects. EPA might help tooth retention.
11. Conjugated Linoleic Acid
(11-1) INHIBITION OF LIPID ACCUMULATION BY TRANS10, CIS12 CLA IN ADIPOCYTES IS
MEDIATED BY ADIPOGENIC MARKER GENES
Linda Granlund, Jan I. Pedersen and Hilde I. Nebb, Department of Nutrition, Institute of Basic Medical Science, University of Oslo, Norway
Conjugated linoleic acids (CLA) is a group of polyunsaturated fatty acids found in ruminant products, where the predominant isomers are cis9,trans11 (c9,t11) and trans10,cis12 (t10,c12 t10,c12) CLA. We have previously shown
that t10,c12 CLA prevents lipid accumulation in mature adipocytes by acting as a PPARg modulator. The objective of this study was to further establish the molecular mechanisms underlying the lipid preventive effect of t10,c12 CLA, with
focus on time point and duration of treatment during adipogenesis. We have shown that t10,c12 CLA treatment has its most attenuating effect early day (D) 0-6 during differentiation. Treatment during this period is sufficient to prevent lipid
accumulation in mature adipocytes. The adipogenetic marker genes PPARg and C/EBPa are both down-regulated after treatment within the period from D0-6, while additional treatment also down-regulates the expression of liver X
receptor a (LXRa), aP2 and CD36. The inhibitory effect of t10,c12 CLA on expression of these genes reflects the subsequent attenuation of lipid accumulation observed in mature adipocytes. Taken together, our data indicate that
inhibition of lipid accumulation induced by t10,c12 CLA treatment during adipocyte differentiation is associated with a tight regulatory cross-talk between early (PPAR? and c/EBP?) and late (LXR?, aP2 and CD36) adipogenetic marker
genes.
(11-2)
INCORPORATION OF CIS-9,TRANS-11 CONJUGATED LINOLEIC ACID INTO PLASMA AND CELLULAR LIPIDS IN MEN FED DAIRY PRODUCTS ENRICHED IN THIS ISOMER
GC Burdge1, S Tricon2, EL Jones2, JJ Russell1, KJ Shingfield3, DE Beever3, RF Grimble1, CM Williams2, P Yaqoob2, PC Calder1. 1Institute of Human Nutrition, University of Southampton, UK, 2Hugh Sinclair Unit of Human Nutrition & 3Centre for Dairy Research,
University of Reading, UK
Studies in animals suggest consumption of conjugated linoleic acid (CLA) may have beneficial effects on health, although human studies using encapsulated CLA preparations have produced equivocal results. We investigated the
effect of substituting dairy products naturally enriched in cis-9, trans-11 (c9,t11) CLA for habitual dairy foods on plasma phosphatidylcholine (PC) and peripheral blood mononuclear cell (PBMC) fatty acid composition in healthy men. 7 men
(aged 43±8y) consumed c9,t11CLA-enriched milk, cheese and butter (providing 1.49g c9,t11CLA /day) for 6 weeks and 5 men (aged 44±7y) consumed control dairy products (0.17g c9,t11CLA /day). Consuming the control products
did not alter the c9,t11CLA content of plasma PC (0.16±0.04 g/100g total fatty acids (TFA)) or PBMC (0.07±0.04 g/100g TFA). Consuming the CLA-enriched products increased c9,t11CLA concentration in plasma PC from
0.17±0.04 g/100g TFA to 0.52±0.24 g/100g TFA (P=0.01) and PBMC from 0.07±0.02 g/100g TFA to 0.23±0.03 g/100g TFA, (P<0.0001), which were greater than the control group (both 3.3-fold, P=0.009 and P<0.0001, respectively). This
was comparable to the change in plasma PC and PBMC c9,t11CLA concentration in men consuming 1.2g /day encapsulated c9,t11CLA [Burdge et al. (2004) J. Lipid Res. 45, 736-41]. These data show that CLA-enriched dairy
products are a suitable means for increasing c9,t11CLA concentration in blood and cellular lipids in humans, and may be as effective as encapsulated CLA.
(11-3) EFFECT OF CONJUGATED LINOLEIC ACID (CLA) ON ADIPOSE TISSUE FATTY ACID
METABOLISM IN THE HAMSTER
Flux,C.L., Lock, A.L.*, Buttery, P.J., Bauman, D.E.*, and Salter, A.M. Division of Nutritional Biochemistry, School of Biosciences, University of Nottingham, U.K and *Department of Animal Science,
Cornell University, Ithaca, USA
Dietary CLA reduces adipose tissue deposition in some species including the mouse and the pig. It also reduces the activity and/or expression of stearoyl coenzyme A desaturase (SCD), thereby lowering the monounsaturated fatty acid
(MUFA) content of tissues. Here, we investigate the effect of CLA on adipose tissue fatty acid composition and lipogenic gene expression in the Golden Syrian hamster. Male hamsters (n=9/group) were fed chow supplemented
with either 2% rapeseed oil (control) or diets where the oil was replaced by 0.5, 1 or 2% CLA, for 7 weeks. CLA was 90% pure and contained equal amounts of the cis-9, trans-11 and trans-10, cis-12 isomers. CLA supplementation had
no effect on body weight gain or food intake but, at the 0.5% level, it reduced total carcass fat by approximately 10% (p=0.02) with no further reduction at higher doses. While both isomers accumulated in the tissues in a dose dependent
manner, the mass of the perirenal adipose tissue depot was unaffected by CLA. CLA decreased SCD activity in this depot with the total saturated fatty acids (C14:0, C16:0, C18:0) increasing (25% vs 36%) and MUFA (C14:1, C16:1,
C18:1) decreasing (50% vs 36%), as a proportion of total fatty acids (control vs 2% CLA, p<0.001). While significant increases in acetyl coenzyme A carboxylase (p<0.001) and fatty acid synthase (p= 0.006) mRNA concentration were activity but does not appear to effect gene expression.
(11-4)
ESTIMATION OF THE DAILY INTAKE OF THE CIS-9, TRANS-11 AND TRANS-10, CIS-12 ISOMERS OF CONJUGATED LINOLEIC ACID (CLA) OF A COHORT OF HEALTHY ADULT
UK VOLUNTEERS
Sohail Mushtaq, Dr Kirsty Hunter, Dr Heather Mangiapane,Nottingham Trent University, School of Land-based Studies, UK
Conjugated linoleic acid (CLA) is the term used to describe the geometric and positional isomers of octadecadienoic acid (18:2) with conjugated double bonds. The cis-9, trans-11 CLA isomer is the most abundant isomer of CLA in the
diet, with dairy products and ruminant fats being the richest sources. The quantity of cis-9, trans-11 CLA and trans-10, cis 12 CLA in a range of UK foodstuffs (112 foods) was determined
using triple-column silver ion HPLC. The cis-9, trans-11 CLA content ranged from 1.93 mg/g lipid (mild cheddar) to 7.32 mg/g lipid (processed cheese) in cheeses, from 0.87 mg/g lipid (ice cream) to 3.71 mg/g lipid (double cream) in
dairy products and from 2.88 mg/g lipid (Swedish meatballs) to 6.00 mg/g lipid (minced lamb) in meat products. Cis-9, trans-11 CLA values for chocolate and sweets ranged from 0.29 mg/g lipid (chocolate Swiss roll) to 4.81mg/g lipid
(butter mint). The trans-10, cis-12 CLA isomer was not detected in the food samples examined. To provide information about dietary CLA intakes in the UK, a study was performed to estimate the daily intake of CLA
in a cohort of 16 healthy volunteers (9 female, 7 male; mean (± sd) age = 28 (±9) years; mean BMI (± sd) = 24.0 kg/m2 (± 2.7) with a seven-day weighed-intake food diary. The information from weighed-intake diaries combined with the
CLA isomer contents of various UK foodstuffs was used to estimate the daily intake of the cis-9, trans-11 and trans-10, cis-12 CLA isomers. The mean daily intake (± sd) of cis-9, trans-11 CLA in the cohort was estimated to be 0.08 g/day
(± 0.05). This compares closely to a value of 0.095 g/day (total CLA) in a study carried out in Canadian volunteers by Ens et al., (2001) but is much lower than values of 0.5 -1.5 g/day (total CLA) which were reported in a study with
Australian volunteers (Parodi et al., 1994).
(11-5)
THE EFFECT OF COMBINED CLA AND ALPHA-LINOLENIC ACID ON PLASMA DHA LEVELS IN HUMANS
Nadia M Attar-Bashi1, Duo Li2 and Andrew J Sinclair1. 1Food Science, RMIT University, Melbourne, Australia,2Department of Food Science & Nutrition, Zhejiang University, Hangzhou, China
The synthesis of 22:6n-3 is limited in healthy individuals, with the rate-limiting step being the peroxisomal oxidation of 24:6n-3 to 22:6n-3. Conjugated linoleic acid (CLA) has been shown to activate peroxisome proliferator-activated
receptor alpha (PPARa) in mice, resulting in hepatic peroxisomal proliferation. The aim of the study was to determine whether supplementing healthy subjects’ diets with 18:3n-3 and CLA would lead to an increase in 22:6n-3 levels in
plasma lipids. Twenty-two healthy male and female volunteers were recruited and randomly allocated, by gender, to receive either 20mL of flaxseed oil plus 3.2g CLA (c9,t11-18:2, t10,c12-18:2,Tonalin capsules) per day or 20mL of
flaxseed oil and soybean oil capsules (placebo) per day for 8 weeks. Blood and forehead sebum samples were collected at baseline, 4 and 8 weeks. There was no significant increase in plasma 22:6n-3 concentration or
composition (% of total fatty acids) in the CLA group (n=11) compared with the placebo group (n=8). Plasma concentrations and proportions of 18:3n-3, 20:5n-3 and 22:5n-3, and of 18:3n-3 and 20:5n-3, increased significantly in
the CLA group and the placebo group, respectively at 4 and 8 weeks compared with baseline. There was no significant increase in 18:3n-3 levels in sebum during the time of the study and no significant difference in the fatty acid profile of
the sebum between the two groups. These results showed that CLA was not effective in enhancing plasma 22:6n-3 levels in humans.
(11-6) SUBSTITUTION OF CONJUGATED LINOLEIC ACID (CLA) FOR LINOLEIC ACID (LA)
CAUSES CHANGES IN HEPATIC FATTY ACID AND CHOLESTEROL METABOLISM IN THE HAMSTER
Cooper, H.S., Bennett, A.J. and Salter, A.M*.,School of Biomedical Sciences, Medical School, Queen’s Medical Centre, University of Nottingham, UK and *Division of Nutritional
Biochemistry, School of Biosciences, University of Nottingham, UK
CLA’s are naturally occurring polyunsaturated fatty acid, produced in ruminant animals and are found in the lipid fraction of meat and dairy products. The specific effect of dietary CLA on lipid metabolism and it’s effect on cholesterol
metabolism are still unclear however, and this study attempts to further elucidate such mechanisms. CLA was substituted for linoleic acid in the diet of hamsters and caused significant increases in both lipogenic and
cholesterogenic genes compared to linoleic acid-supplement animals, with a 3.5 fold increase in SREBP-1c mRNA levels (p<0.001) and a 2-fold increase in SREBP-2 mRNA levels (p<0.05). Similar increases in downstream genes of
both SREBP-1c and SREBP-2 were also observed. There were no overall changes in liver or adipose tissue mass in any of the experimental animals. This suggests that CLA’s cause changes in both lipogenic and cholesterogenic gene
expression in the absence of steatosis/peroxisome proliferation or major adipose tissue loss in the hamster.
(11-7)
EFFECT OF A VACCENIC ACID (VA)/CONJUGATED LINOLEIC ACID (CLA)-ENRICHED BUTTER ON TISSUE CLA CONCENTATIONS IN THE HAMSTER
Lock, A.L., Salter, A.*, Hurley, M.*, Dwyer, D.A., and Bauman, D.E.,Department of Animal Science, Cornell University, Ithaca, USA and *Division of Nutritional Biochemistry, School of Biosciences,
University of Nottingham, UK
Dietary trans fatty acids adversely affect risk of developing atherosclerosis. However little is known about the effect of individual trans isomers. Ruminant milk is relatively rich in VA (C18:1, trans-11). Here we investigate whether VA
(from butter), is converted to cis-9, trans-11 CLA by the action of stearoyl coenzyme A desaturase (SCD) and may therefore not have the adverse effects of other trans fatty acids. Control butter and VA/CLA enriched butter were
produced by manipulating natural dietary components fed to dairy cows. The content of CLA (cis-9, trans-11 isomer) and VA was 3.61 and 15.36 g/100g fatty acid respectively in the enriched butter and 0.44 and 1.39 in the normal butter.
Male hamsters were fed chow- based diets containing 20% added fat as 5% control butter + 15% VA/CLA- enriched butter +/- 0.5% sterulic oil (SO), a potent inhibitor of SCD activity. Addition of SO reduced the desaturase index (C18:1
cis-9/C18:0 + C18:1 cis-9) from 0.90 to 0.75 and 0.90 to 0.78 in the perirenal and omental adipose tissue depots respectively, indicating inhibition of SCD. In both depots SO caused a 37% decrease in the amount of cis-9, trans-11
CLA and a similar rise in the amount of VA. These data clearly indicate that dietary VA can be converted to CLA in the hamster, a commonly used model of human lipoprotein metabolism, thereby making an important contribution to the
whole body supply of CLA.
Supported in part by USA National Dairy Council.
(11-8)
EFFECTS OF CIS-9, TRANS-11 CONJUGATED ACID ON CERAMIDE METABOLISM IN HUMAN INTESTINAL CELLS
Linda V. Larsen1 , Stig Purup2 & Lars I. Hellgren1,1Biochemistry and Nutrition Group, BioCentrum-DTU, Technical University of Denmark. 2 Animal Nutrition and Physiology,
Danish Institute of Agricultural Sciences
Conjugated linoleic acid is a group of fatty acids with pleiotropic biological activity. In the human diet, the cis-9, trans-11 isomer (rumenic acid) is normally the dominating species. Intake of rumenic inhibits chemically induced tumorigenesis
in mammary, skin and colon and it has been showed that this is due to reduced proliferation as well as increased apoptosis. Since these effects are mimicked by increased intracellular ceramide concentration, we hypothesized that
the anticarcinogenic properties of rumenic acid is due to alterations in the sphingolipid metabolism. To test this hypothesis, we have compared the rate of TNF-? stimulated ceramide formation from radiolabelled sphingomyelin in
the human intestinal cell line FHS-74Int, when incubated in the presence of rumenic acid or linoleic acid. We have also studied the effects of rumenic acid on basal rate of synthesis and degradation of ceramide and sphingomyelin. The
results show that there are no difference in the rate of synthesis for either sphingomyelin or ceramid in cells that have been grown in the presence of rumenic acid or linoleic acid, while rumenic acid cause a substantial increase in the
turn-over rate of radiolabeled ceramide. Hence, our results indicate that rumenic acid alters ceramide metabolism and that this partly could explain the biological activity of this CLA isomer.
(11-9)
EFFECTS OF DIETARY CONJUGATED LINOLEIC ACID (CLA) ON FATTY ACID COMPOSITION OF EGG-YOLK LIPIDS AND EGG QUALITY
RB Kostogrys1, PM Pisulewski1, B. Szymczyk2, M Franczyk1 1Department of Human Nutrition, Agricultural University of Kraków, Poland, 2Department of Animal Nutrition, Institute of Animal Production, Balice, Poland
The objective of this study was to develop CLA-enriched eggs as functional products. Forty-five laying hens were randomly distributed into five groups and maintained in individual laying cages for 4 weeks. They were fed a
commercial layer supplemented with CLA isomers (cis-9, trans-11 and trans-10, cis-12; Luta CLA 60; BASF): I-0.0, II- 0.25, III-0.50, IV-0.75 and V-1.00%, combined with rapeseed oil (4%). On week 4, eggs were collected daily (5 eggs
per treatment) and analysed for fatty acids with a HP 5890 GC. Separate eggs (3 eggs per treatment) were stored for 7, 28, or 56 d at 4oC to study their quality characteristics and hardness of egg yolks from hard-cooked eggs. Feeding
the CLA-enriched diets resulted in significant accumulation of CLA isomers (P<0.01) in egg-yolk lipids: I-0.0, II-0.7, III- 1.1, IV-1.6, and V-2.9% of total fatty acids. Moreover, SFA concentrations were increased (I-30.4, II-36.3, III-41.6, IV-
43.1 and V-41.7%; P<0.01) as dietary CLA increased, those of MUFA were decreased (I-50.1, II-42.1, III-37.9, IV-36.6 and V-36.5%; P<0.01) and those of PUFA were unaffected (I-19.5, II-21.6, III-19.5, IV-20.3 and V-21.8%). The above
changes in non-CLA fatty acid concentrations were observed only up to the 0.5% dietary CLA level. Duration of refrigerated storage increased the yolk mass and decreased that of albumen mass. Dietary CLA did not affect the
hardness of hard-cooked yolks when fed up to the 0.5% level and then it sharply increased their hardness at the 0.75 and 1.00% levels, regardless of storage. In conclusion, the nutritional enrichment of hen eggs with CLA isomers, when
fed up to the dietary level of 0.5%, affects adversely egg yolk fatty acid composition. However, it does not affect their sensory quality (i.e. hardness).
(11-10) LYMPHATIC TRANSPORT OF STRUCTURED OILS CONTAINING CONJUGATED
LINOLEIC ACIDt10,c 12
Straarup, E.M.; Porsgaard, T. and Mu, H. Technical University of Denmark, BNG, BioCentrum-DTU, Lyngby
Conjugated linoleic acids (CLA) are a group of unsaturated fatty acids with 18-carbon atoms and at least two conjugated double bonds. One of these fatty acids, CLAt10, c12, was shown to have some health benefits regarding
obesity and cancer. Recent studies have shown that lipid structures play an important role for the absorption of fatty acids. Therefore structured triacylglycerols containing CLA were manufactured by interesterification with a regiospecific
lipase. The structured triacylglycerols contained conjugated linoleic acid (CLAt10,c12) and either octanoic acid or oleic acid and were of the following structures: 8:0/CLAt10,c12/8:0, CLAt10,c12/8:0/ CLAt10,c12, 18:1/CLAt10,c12/18:1 and CLAt10,
c12/18:1/ CLAt10,c12.The lymphatic transport of CLAt10,c12 from these four oils with different triacylglycerol structures and fatty acid profiles
was examined in rats.
12. Lipoproteins, Lipaemia and Lipoprotein Metabolism
(12-1) ω-3 FATTY ACIDS MODIFY LIPID SYNTHESIS, LIPOPROTEIN ASSEMBLY AND
PROTEASOMAL DEGRADATION OF APOLIPOPROTEIN B IN THE INTESTINE OF PSAMMOMYS OBESUS
Emile Levy1,2, Ernest Seidman1,3, Edgard Delvin1,4 and Ehud Ziv5,1Research Centre, Departments of 2Nutrition, 3Pediatrics and 4Biochemistry, Hôpital Sainte-Justine, Montréal (QC), Canada; and
5Diabetes Unit, Haddasah University Hospital, Israel
Psammomys obesus sand rats develop a severe insulin resistance and hyperglycemia when transferred from their native food in desert regions to laboratory rodent diets. The progression of nutritionally-induced diabetes in this animal
model resembles the development of insulin resistance and type 2 diabetes in certain human populations. The aim of the present study is to determine the influence of ω-3 fatty acids on the intracellular events governing intestinal fat
transport. We approached this question by placing the animals on a regular diet enriched either with ω-3 or saturated fatty acids for 4 weeks. Low plasma levels of insulin, glucose, triglycerides and cholesterol characterized the animals
on long-chain ω-3 compared with those on saturated fatty acids. Accordingly, intestinal de novo lipid synthesis was reduced as noted by the incorporation of 3H2O and the measurement of lipogenic enzymes in Psammomys obesus on ω-3 diet. As evidenced in jejunal explants incubated with [14C]-oleic acid substrate, the esterification and secretion of radiolabelled lipids was diminished in this animal group. Furthermore, jejunal explants cultured with [35S]-methionine
showed a significant (p<0.01) decline in apolipoprotein B-48 biogenesis in parallel with a diminished secretion of triglyceride-rich lipoproteins. Clearly, the consumption of ω-3 fatty acids stimulated the degradation of newly synthesis. Overall, our findings stressed the beneficial effects of ω-3 fatty acids on the hypertriglyceridemia
synthesized apo B-48 and inhibition of proteasome by N-acetyl-leucyl-norleucinat re-established radioactive apo B-48
characterizing insulin resistance and diabetes. These fatty acids were able to interfere with the intracellular mechanisms involved intestinal lipid transport, including de novo lipid synthesis, proteasomal apo B degradation and
lipoprotein assembly.
(12-2) INFLUENCE OF MENOPAUSAL STATUS ON POSTPRANDIAL LIPOPROTEIN
METABOLISM IN PRE AND POST-MENOPAUSAL WOMEN
Elizheeba C. Abraham, Anne M. Minihane,Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, The University of Reading, UK
Menopausal
status is a significant determinant of coronary heart disease (CHD) risk. A more
pro-atherogenic lipoprotein profile, including an increase in fasting
triglyceride (TAG) levels, is thought to be partly responsible for the increased
risk in postmenopausal women. Although postprandial TAG is known to be a more
significant determinant of CHD risk relative to fasting levels, information on
the effect of menopausal status on postprandial TAG handling is lacking.
Postprandial assessment was carried out on 22 healthy female volunteers.
Following a standard breakfast (t=0h, 49g fat) and lunch (t=5.5h, 31g fat)
regular blood samples were taken up to 8h post-breakfast. In addition at fixed
timepoints ((t=0, 4, 6.5h) lipoprotein (chylomicrons, VLDL, LDL, HDL) separation
was carried out. Significantly lower
mean BMI, fasting TC and glucose was evident in the premenopausal (n=12)
compared to postmenopausal (n=10) subgroups (P<0.05). Although no
significant inter-group differences were observed for fasting TAG,
postmenopausal women had a 31% higher area under the TAG postprandial curve
(AUC) and a 54% higher incremental AUC (IAUC) compared to premenopausal women.
Analysis of the lipoprotein subfractions, indicated significantly higher LDL-TAG
at t=0h and VLDL-TAG at 4h in the postmenopausal participants. Delayed
postprandial TAG-rich lipoprotein clearance may make a significant contribution
to the increased CHD risk in postmenopausal women.
(12-3) LIPID LOWERING EFFECTS OF BIOACTIVE PROTEINS
Gudbrandsen OA, Wergedahl H and Berge RK,The Lipid Research Group, Institute of Medicine, Haukeland University Hospital, University of Bergen, Norway
A growing body of evidence indicates that not only dietary fats but also dietary proteins and isoflavones influence the lipid metabolism and improve the blood lipid profile in both animals and humans. We recently performed a dietary
experiment on 26 middle-aged women, who consumed salmon which were fed either fish oil or soy oil based feed for 16 weeks in a crossover study. The diets affected the fatty acid composition in the salmon muscle differently, but both
diets had a positive effect on the lipid profile in the women. This suggests that not only fish oil, but also other components in salmon have positive effects on plasma lipids.
To investigate the effects of different dietary proteins on the lipid homeostasis, genetically obese Zucker fa/fa rats were fed fish protein hydrolysate (FPH) or fermented bacterial proteins in the absence or presence of isoflavones. All dietary
proteins affected the fatty acid composition in liver, heart and plasma when compared to casein fed rats. Soy protein, as well as FPH and the fermented proteins reduced the plasma cholesterol level and increased the HDL/LDL
cholesterol ratio. The gene expressions of desaturases, lipoprotein lipase, CYP7A1 and LDL and VLDL receptor in liver, muscle and white adipose tissue were measured. Based on our results, it seems that the mechanisms of action of
the dietary proteins are different, although all lowered the plasma cholesterol level. The results from these studies and possible impact on diabetes and cardiovascular diseases will be discussed.
(12-4) EFFECT OF DHA ON TISSUE TARGETING AND METABOLISM OF PLASMA
LIPOPROTEINS
Alla Polozova and Norman Salem, Jr. Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, USA
It is well established that diets rich in omega-3 fats have beneficial health effects ranging from improved neural functions to significantly reduced risks of arrhythmias and heart disease. Dietary omega-3 polyunsaturated fatty acids
and docosahexaenoic acid (DHA) in particular, selectively accumulate in certain tissues, such as brain, heart and retinas. In spite of significant research efforts, the mechanisms responsible for the selective transport of DHA to the
target organs have not been elucidated. More than 95% of DHA in plasma is present in esterified form in plasma lipoproteins. We hypothesized that fatty acid composition of lipoproteins is directly involved in regulation of their
targeting to specific tissues and metabolism. To examine the effect of the DHA content of lipoproteins on their metabolism in vivo, we developed a radioisotope labeling and tracking method. Purified high and low density
lipoproteins (HDL and LDL) were labeled with lipid tracers carrying 3H or 14C radioisotopes. To mimic dietary-related changes in fatty acid composition of lipoproteins we incorporated lipids acylated with either DHA, arachidonic or oleic
acids into the purified particles. The amount of added lipids did not cause detectable alterations in the morphology of the lipoproteins. Levels of radiotracers in blood and in several target tissues such as brain, heart, liver, muscle and
adipose were determined at 1.5, 3 and 24 hours after IV injection into C57Bl/6J mice. No statistically significant differences were detected in the tissue distribution of tracers introduced into HDL with modified lipid composition
compared to control unaltered particles. In contrast, we found a significantly higher proportion of radiolabel associated with LDL enriched in DHA in heart, brown adipose and brain tissues. Uptake of labels almost doubled for heart and
brown adipose tissues at 1.5 and 3 hrs, and it was 30% higher for brain tissues at 24 hours. The tissue distribution of labels from the same particles enriched in arachidonic or oleic acids did not show a statistically significant difference
from unaltered control lipoproteins. These findings point to the possible role of DHA in control of LDL metabolism and involvement of the lipoproteins in transport of omega-3 PUFA to target organs.
(12-5) INFLUENCE OF TRIACYLGLYCEROL STRUCTURE ON POSTPRANDIAL LIPAEMIA
S.E.E. Berry & T.A.B Sanders. Nutrition Food and Health Research Centre, King’s College London, UK
Exaggerated postprandial lipaemia may increase risk of coronary heart disease by contributing to both thrombotic and
atherogenic processes. We report differences in postprandial lipaemia in healthy male subjects induced by 50g stearic acid rich fats with different TAG structures.
In two studies (Sanders TA 2003, Berry 2003a), using mixtures of oleate and stearate rich TAG, an asymmetrical TAG resulted in a reduced postprandial lipaemia compared with a symmetrical TAG (cocoabutter). A third study, which
employed shea butter, found no difference between symmetrical and asymmetrical TAG derived from shea butter. A subsequent study showed that unrandomized shea, which is rich in symmetrical TAG, resulted in a reduced lipaemia
compared with triolein (Berry 2003b). The asymmetrical TAG used in studies 1, 2 & 3 had solid fat contents at 37ºC, as determined by NMR, of 38%, 23% and 35% respectively. The symmetrical shea had a solid fat content of 43% at 37ºC
and thus despite consisting of symmetrical TAG had markedly different physical characteristics compared with the symmetrical TAG used in studies 1 & 2 (cocoabutter) which had less than 1% solid fat at 37ºC, and triolein which has
no solid fat at 37ºC.These findings suggest that differences in physical properties of these fats may play an important role in determining
their rates of digestion and absorption and so may explain the observed differences in postprandial lipaemia.
(12-6) EFFECTS ON PLASMA LIPIDS WHEN PLANT STEROL ENRICHED FAT SPREAD OR
CARBOHYDRATE PROVIDE REPLACEMENT ENERGY FOR SATURATED FATTY ACIDS
Murray Skeaff1, Christian Thoma1, Alex Chisholm1, Jim Mann1, Sheila Williams2. University of Otago, 1Department of Human
Nutrition, 2Department of Preventive and Social Medicine, Dunedin, New Zealand
To determine the effects on plasma cholesterol of replacing a plant sterol enriched fat spread with carbohydrate, twenty-nine healthy volunteers with raised low density lipoprotein cholesterol concentrations were assigned to follow in
random order three diets; a typical New Zealand diet high in total (34%kJ) and saturated (15%kJ) fat, a cholesterollowering diet reduced in total (30%kJ) and saturated fat (8%kJ) but including a plant sterol spread, and the same
cholesterol-lowering diet with the plant sterol spread isocalorically replaced with carbohydrate (total fat, 26%kJ; saturated fat 7%kJ). All foods were provided and each diet was followed for four weeks. Mean (SD) plasma low density
lipoprotein cholesterol concentration declined from 4.68 (0.92) mmol/L on the high saturated fat diet to 4.12 (0.83)
mmol/L (P<0.001) on the carbohydrate diet and 3.76 (0.84) (P<0.001) on the plant sterol diet. The 20% decrease on the plant sterol diet was significantly greater (P<0.001) than the 12% decrease on the carbohydrate diet. Relative to
the high saturated fat diet, mean (95%CI) plasma high density lipoprotein cholesterol concentration declined by -0.11 (- 0.16 to -0.06) mmol/L on the carbohydrate diet but changed little on the plant sterol diet, -0.03 (-0.09, 0.02). Including a
plant sterol fat spread in a cholesterol-lowering diet produces a more favourable plasma lipid profile than replacementof the spread with carbohydrate.
(12-7)
LIPOPROTEIN COMPOSITIONAL DYNAMICS BY QUANTITATIVE LIPID ANALYSIS OF POSTPRANDIAL HUMAN PLASMA
Angela Zivkovic1, Steve Watkins2, J. Bruce German1,1University of California at Davis, 2Lipomics Technologies Inc.
The postprandial state is becoming recognized as a discrete metabolic window in which variations in diet have significant effects on overall health. The majority of information on the composition of lipoproteins has been obtained
from fasted plasma assuming that the composition is relatively static. New approaches will be needed to describe and ultimately understand the metabolic events occurring after consumption of both fat rich and carbohydrate rich meals.
Blood samples were obtained at fasting and at 3.5 hours after meal ingestion from volunteers consuming a high fat breakfast (65% fat). The lipoprotein classes were separated and quantitative lipid profiling was then performed. The
sheer volume of data that such analytical platforms produce in a dynamic model such as postprandial lipid metabolism requires additional software tools to display, analyze and interrogate them. With such tools in place, the changes in
lipid composition of the major classes of lipoproteins during the post-prandial period were striking. All classes of lipids, phospholipids, triglycerides and sterol esters were altered in response to the post-prandial state. Metabolic systems
approaches are now being developed to link measured lipid compositions to the metabolic pathways that sculpt them.
(12-8) WEEKLY CHANGES IN PLASMA AND LIVER LIPIDS, AND BLOOD GLUCOSE LEVELS
IN MICE FED DOCOSAHEXAENOIC ACID, EICOSAPENTAENOIC ACID, AND FISH OIL DIETS
Tomoyuki Higuchi, Nobuya Shirai and Hiramitsu Suzuki,National Food Research Institute, Kannondai 2-1-12, Tsukuba, Ibaraki, Japan
To clarify the effect of the dietary docosahexaenoic acid (DHA, 22:6n–3), eicosapentaenoic acid (EPA, 20:5n-3), and fish oil on glucose and lipid metabolism, the changes in blood glucose (Gl), plasma total cholesterol (T-chol),
triglyceride (TG), and phospholipid (PL) levels of male Crj:CD-1 mice which fed the DHA, EPA, and fish oil for 17 weeks were determined. Animals fed the diets which contained 6% lard (lard group), 6% fish oil (fish oil group), 4.5%
DHA ethyl ester plus 1.5% lard (DHA group), 0.38% EPA ethyl ester plus 4.62% lard (EPA group), and 4.5% DHA ethyl ester plus 0.38% EPA ethyl ester plus 1.12% lard (DHA+EPA group), respectively. Plasma PL level was significantly
lower in the fish oil and DHA+EPA groups than in the lard group on the week 2. Plasma T-chol level was significantly lower in the fish oil group than in the lard group on the week 6. Blood Gl level was significantly lower in fish oil group successively DHA and EPA intakes. Plasma Gl, TG and PL levels, and liver T-chol, TG and PL levels of the fish oil
group after sacrificing on the week 17 were significantly lower than those of the lard group. DHA and EPA content in the plasma and liver reflected their diet composition. The results indicate that fish oil, mainly DHA and EPA, decreases
blood Gl level subsequent to reduce the plasma lipid levels in mice.
(12-9) INFLUENCE OF GENDER ON RESPONSE OF LIPID METABOLISM TO DIETARY FATTY
ACIDS IN THE HAMSTER
A. Morise(a), J. Mourot(b), P. Weill(c), E. Fénart(d), D. Hermier(e),(a) LEN, Université Paris XI, Orsay, (b)INRA UMR-VP, L’ Hermitage, (c)Valorex, La Messayais, Combourtillé. (d)ONIDOL, Paris
(e)UPNCA, INAPG, Paris, France
N-3 fatty acids and estrogens are recognised as protective factors against cardiovascular diseases, especially through their regulation of lipid metabolism. The interactions between these factors were investigated in male and female
hamsters, fed for 7 weeks diets containing 17% lipids and rich in either saturated fatty acids (SFA, based on butter) or in α-linolenic acid (ALA, based on linseed oil). Gender predominated over dietary fatty acids on plasma concentration
of cholesterol (CT) and LDL, and on hepatic SR-BI concentrations that were lower by 38%, 40% and 50% respectively in females. Dietary effects on both genders were few: insulinemia and phospholipemia were 42% and 16% lower in
animals fed the ALA diet. Most of the effects concerned males exclusively; compared to males fed the SFA diet, those of the ALA diet exhibited lower concentration of plasma triglycerides (TG), -38% and HDL, -12% and of hepatic CT, -
25%, TG, -21% and LDL-receptor -33%. Concomitantly specific hepatic activity of carnitine palmitoyl transferase was 130% higher in males fed the ALA diet. In females, none of these parameters was affected by diet. This suggests that
regulation of lipid metabolism by n-3 fatty acids (via PPAR or SREBP notably) could interact with regulations by sex hormones and their receptors on the same targets and could explain why males are more sensitive to dietary fatty
acids.
(12-10)
LACK OF EFFECT OF SUGAR CANE AND SUNFLOWER SEED POLICOSANOLS ON PLASMA CHOLESTEROL IN RABBITS
Karen Murphy1, David Saint2 and Peter Howe1,2,Nutritional Physiology Research Group, 1School of Health Sciences, University of South Australia and 2School of Molecular &
Biomedical Science, University of Adelaide, Australia
Policosanol, a mixture of high molecular weight primary aliphatic alcohols from sugar cane (SCP), reportedly lowers blood cholesterol. We attempted to see whether a similar product derived from winteriser cake during sunflower oil
production (SFP) has cholesterol-lowering potential. Groups of 7-8 normocholesterolaemic rabbits were fed 100mg/kg SCP (Lesstanolâ, Johnson & Barana), 100mg/kg SFP (provided by Goodman Fielder) or vehicle (water/ sunflower oil
emulsion) by gavage at 48hr intervals for 4 wks. Fasting blood samples were taken for lipid analysis at weekly intervals from 1wk beforehand. The table shows changes (mean±SE) in plasma lipids (mmol/L) from averaged pre- and posttreatment
values (* p<0.05).
| |
Total Chol |
HDL-C
|
LDL-C
|
TAG
|
| vehicle |
0.07±0.05
|
0.04±0.04 |
0.05±0.02 |
-0.06±0.02 |
| SFP |
0.05 ±0.04 |
0.03±0.03 |
0.05±0.02 |
-0.06±0.03 |
| SCP |
0.17 ±0.07 |
0.08±0.05 |
0.11±0.03 |
-0.06±0.02 |
Food intake and body weight were unaffected by the treatments and, while LDL cholesterol increased and TAG decreased in all groups, there were no significant effects due to treatment. Thus the cholesterol lowering effect of policosanol was not confirmed in this study, even though 5mg SCP/day was previously found to be effective in rabbits.
(12-11) INFLUENCE OF MODERATE BEER CONSUMPTION ON RED BLOOD CELLS, PLASMA
PROTEINS AND LIPID PROFILE*
Romeo Javier, Nova Esther, Díaz Ligia-Esperanza, González-Gross
Marcela, Marcos Ascensión, Grupo de Inmunonutrición.
Departamento de Metabolismo y Nutrición. Instituto del Frío. Consejo
Superior de Investigaciones
Científicas. C/ Jose Antonio Novais, 10, E- 28040 Madrid, Spain
Subjects and Methods: 27 women and 30 men were assessed at a basal
stage (T0) and were subsequently submitted
The aim of the current study was to find out the effect of moderate
consumption of beer on some blood parameters in healthy adults. to a 30
day-alcohol abstemious period (T1) followed by a 30 day-moderate beer
consumption period (330 ml/d for women
and 660 ml/d for men) (T2). Dietary intake (7-day food record), red
blood cells, lipid profile, and plasma proteins (total proteins,
albumin, prealbumin, complement factors C3 and C4 and immunoglobulins
G, A and M) were measured at T0,
T1 and T2. Results: No changes were found in energy and macronutrient
intake between T1 and T2. Total cholesterol in women
and HDL-cholesterol both in men and women increased significantly in T2
compared to T1. Triacilglyceride levels remained unchanged. Red blood
cell counts, haemoglobin and haematocrit in women, as well as red blood
cells and
haematocrit in men increased in T2. C3 levels increased in women and
immunoglobulin G, A and M concentrations increased in both genders in
T2. The rest of the plasma proteins did not show relevant changes.
Conclusion: Moderate consumption of beer improves plasma lipid profile
by increasing HDL-cholesterol, and shows an enhancing effect on the
levels of red blood cells and immunoglobulins, both in men and women.
* Project sponsored by Centro de Información Cerveza y Salud. Spain.
13. Brain Function and Neurological Disorders
(13-1) FFECT OF DIETARY DOCOSAHEXAENOIC ACID ON ACETYLCHOLINE RELEASEPROCESS IN THE RAT HIPPOCAMPUS
Vancassel S., Aïd S., Langelier B., Alessandri JM, Guesnet P. and Lavialle M., aboratoire de Nutrition et Sécurité Alimentaire, INRA, Jouy-en-Josas, France
The large amounts of docosahexaenoic acid (22:6n-3, DHA) in brain cell membranes is in accordance with the specific role of this n-3 polyunsaturated fatty acid (PUFA) in synaptic regulation. We have previously shown that a diet deficientin n-3 PUFA induced modifications in cholinergic neurotransmission in the rat hippocampus. Here, we examined hether increasing dietary doses of DHA (egg phospholipids) exert a dose-response effect on the release ofacetylcholine (ACh) in the rat hippocampus, compared to a diet totally deficient in n-3 PUFA. The ACh contents in the ynaptic cleft was measured by cerebral microdialysis, and the phospholipid fatty acid composition in neuronalmembranes were analyzed. The mRNA expression levels of synaptotagmin I (syt I), which is a pivotal membrane rotein in synaptic exocytosis, was quantified by using realtime PCR.Results: The DHA incorporation in PE plateaued to 22% of total fatty acids when the diet brought 100 mg DHA / 100 g diet, whereas 2 times higher dietary concentrations were required to match the 4% plateau-value of DHA in PC. Thehippocampal release of Ach in deficient- or in the 100 mg of DHA-supplemented rats was identical. However, the supply of higher doses of DHA induced a significant increase (55-95%) in KCl-induced, and decrease (35-55%) inbasal ACh release. The syt I relative expression level was identical for all the dietary groups. Conclusion: The results showed that matching the DHA plateau value in membrane phospholipids increased theamplitude of Ach release upon stimulating condition. So, we evidenced that n-3 PUFA are involved in the regulation of cholinergic synapse, without modification in expression of the calcium-sensor protein, syt I.
(13-2) N-3 DEFICIENT DIET AFFECTS THE EXPRESSION OF GLUT1 IN ENDOTHELIAL CELLS
AND ASTROCYTES
Pifferi F.1, Guesnet P.1, Roux F.2, Langelier B.1, Alessandri J.M.1 and Lavialle M.1,1 Laboratoires de Nutrition et Sécurité alimentaires, INRA, Jouy en Josas, and 2 Unité Inserm U26, Hôpital Fernand Widal,
Paris, France
We recently hypothesized that alterations in neuronal activity in n-3 deficient rats could partly result from a decrease in brain energetic metabolism (Ximenes et al., J. Neurochem. 2002). In the present work, we have investigated the
impact of the n-3 deficiency on the expression of glucose transporters in brain capillaries and astrocytes (Glut1) and neurons (Glut3). For that purpose, Wistar male rats fed with a control diet or a n-3 deficient diet over one generation
were used. Glucose transporters were measured using western immunoblots of proteins extracted from brain capillaries for dosing
endothelial Glut1 (55kDa), and from brain cortex homogenate for dosing both astrocytic Glut1 (45kDa) and neuronal Glut3. The fatty acid compositions in membrane phospholipid classes purified from brain capillaries and from cortex
were analyzed. A 50% decrease of docosahexaenoic acid (22:6n-3) and a compensatory increase of
docosapentaenoic acid (22:5n-6) were observed in the cortex and capillary membrane phospholipids from deficient rats. These lipid alterations came with a 25% decrease of capillary-Glut1 55kDa and of brain homogenate-Glut1
45kDa, whereas Glut3 remained unchanged in n-3 deficient rats. Thus, n-3 deficiency had an impact on the expression of Glut1 in endothelial cells and in astrocytes, which could explain the reduced utilization of glucose in the deficient
brain. Real-time quantitative polymerase chain reaction is being used to study the process of mRNA Glut1-regulation, which may involve pre- or post-transcriptional events.
(13-3) DIETARY ENRICHMENT WITH OMEGA-3 POLYUNSATURATED FATTY ACIDS IN AGED
RATS – A BIOCHEMICAL AND BEHAVIOURAL STUDY
Simon Dyall, Greg Michael, Robin Whelpton and Adina Michael-Titus,Neuroscience Centre, Institute of Cell and Molecular Sciences, Barts and The London, Queen Mary's School of Medicine and
Dentistry, London, UK
The brain is enriched in polyunsaturated fatty acids (PUFA) of the omega-6 and omega-3 series. During ageing there is a decrease in the content of these PUFA in brain phospholipids. We investigated the effects of dietary enrichment with
the omega-3 PUFA eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on age-related changes in lipid content and behaviour. 24 month-old male Wistar rats were fed a diet supplemented with omega-3 PUFA for 12
weeks. The daily intake was 145-160 mg EPA and 95-110 mg DHA/kg rat, with an omega-6/omega-3 ratio of 1, provided by the addition of Maxepa® oil to the diet. The control group received a standard diet with an omega-6/
omega -3 ratio of 14. The prefrontal cortex, hippocampus and striatum were analysed for phospholipid content and fatty acid composition. After lipid extraction phospholipids were separated by solid phase extraction and thin-layer There was an age-related decrease in AA and DHA in all structures. The decrease in DHA was corrected by
supplementation in most phospholipids. Behaviour was assessed by measuring locomotor activity and performance in psychomotor tests. The locomotor activity of the Maxepa® group was higher in all time-periods and was significantly
greater in week 8 and when weeks 2, 8 and 12 of treatment were combined. Therefore, the Maxepa® group were more exploratory than the control group. The age-related deterioration in behaviour in psychomotor tests seen in control
animals was also reversed by treatment. These observations support the neuroprotective potential of omega-3 fattyacids in ageing.
(13-4) DOCOSAPENTAENOIC ACID N-6 CANNOT SUBSTITUTE FOR DOCOSAHEXAENOIC
ACID FOR NERVOUS SYSTEM FUNCTION
S-Y. Lim1, J. Hoshiba2 and N. Salem, Jr3. 1Division of Ocean and Science, Korea Maritime University, Busan, Korea, 2Department of Animal Resources, Okayama University
Medical School, Okayama, Japan and 3Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, USA
Many studies suggested that n-3 fatty acid deficiency leads to a loss in brain docosahexaenoic acid (DHA) with a reciprocal increase in docosapentaenoic acid (DPAn-6), and that these alterations in brain fatty acid composition result
in losses of neural function. This study determined whether provision of preformed dietary DPAn-6 could replace dietary DHA in rats with an artificial rearing method when tested by spatial task performance at 8 wks of age. Newborn
rats were separated at 2 days of age from their mothers that had been fed on an n-3 adequate diet containing alinolenic acid (LNA) as 3.1 % of the total fatty acids. The pups were moved to a rearing cage and fed artificial rat milk
that was n-3 fatty acid deficient (LA), 1% DHA (DHA), 1% DPAn-6 (DPA) or 1% DHA:DPAn-6 (2:1, DHA/DPA) using an artificial nipple and nursing bottle. Rat pups were fed on the respective artificial milk by hand and weaned onto brain DHA than the dam-reared (Dam’s) or DHA diet groups which was largely replaced by an increase in brain DPAn-6
(P<0.001). In an activity measure, the moving time was greater in the DPAn-6 group in comparison to the dam-reared or DHA-containing groups (P<0.05) but not different than the LA group. In the Morris water maze test, rats in the LA
and DPA groups exhibited longer escape latencies compared to the Dam-reared and DHA groups (P<0.05) and had a defect in spatial memory as assessed by the probe trial. In conclusion, DPAn-6 feeding could not substitute for the
functions of DHA in the nervous function as assessed by spatial task performance.
(13-5) VISUAL SYMPTOMS AND FATTY ACID STATUS IN DYSLEXIA
A. Shrier1, E.Cyhlarova1, M.A.Ross1, J.R.Dick2, E.E.MacKinlay2, J.G.Bell2 and A.J.Richardson1,(1) University Lab. of Physiology, Oxford; (2) Lipid Nutrition Group, Institute of Aquaculture, University of Stirling, Scotland, UK
Existing evidence suggests that deficiencies in certain highly unsaturated fatty acids (HUFA) may contribute to some clinical features of dyslexia. The possible mechanisms involved are not known, but existing research has established
that (a) n-3 HUFA are particularly important for visual function, (b) impairments of visual processing are associated with dyslexia, and (c) mild physical signs of fatty acid deficiency correlate with self-reported visual symptoms. The
hypothesis tested in this study was that visual symptoms in dyslexic adults would vary as a function of their fatty acid status.
32 dyslexic adults and 25 matched controls completed self-report measures of visual and other symptoms associated with dyslexia. Polar lipid composition of RBC membranes was determined by capillary gas-liquid chromatography.
Associations between visual symptoms and concentrations of RBC n-3 and n-6 fatty acids were explored using correlational analyses both within and across groups.
In the dyslexic group only, high concentrations of arachidonic acid were significantly associated with visual symptoms when reading; and in both groups, a very strong negative correlation was found between n-3 and n-6 concentrations.
These results are consistent with the idea that dietary supplementation with n-3 fatty acids may help some dyslexic adults, although controlled treatment trials to investigate this possibility are still in progress.
(13-6) ACUTE STRESS AND LIPIDS IN RATS
1Alonso H,2 Bosch V,2 Trejo E, 2 Golfetto I, 1 Nutrition and Dietetic School, 2 Golfetto Institute of Experimental Medicine, Physiopathology Department, Faculty of Medicine, Central University of Venezuela
Methods: Sprage Dawley rats under acute stress by immobilization (n=34) were sacrificed. Total and free cholesterolStress is associated with the development of ischemic heart disease. Studies in humans and animals support the relation between stress and plasma lipids concentration. Most studies have been focused in total cholesterol (TC) and
triglycerides (TG). Few studies analyze fatty acids. Aims: We wanted to study how acute stress affects fatty acid composition in plasma, liver and adipose tissues. and triglycerides were analyzed by enzymatic methods. Total fatty acids from triglycerides, cholesterol esters (CE) and
phospholipids (PL) were analyzed by gas liquid chromatography. Results: Among the main fatty acids the only one that increased in the three fractions, was liver arachidonic acid (AA)
(p<0.005): TG (2.7 ± 0.2 stressed vs. 2.4 ± 0.2 control.). CE (7 ± 0.4 stressed vs. 4 ± 0.3 control). and PL ( 23 ± 0.4 stressed vs. 20 ± 0.6 control). It was also increased in PL of adipose tissue (2.31 ± 0.2 stressed vs. 1.6 ± 0.22
control.). Conclusions: During stress there is a mobilization of fatty acids from different stores. There is a homeostasis of main
fatty acids during stress.
(13-7)
DIFFERENTIAL PHOSPHOLIPID INCORPORATION OF 22:6N-3 IN HUMAN NEUROBLASTOMA CELLS INCUBATED WITH GRADED DOSES OF 18:3N–3, 22:5N–3
OR 22:6N–3.
Perruchot MH, Alessandri* JM, Langelier B, Guesnet P , Lavialle M.,Inst. Natl. Rech. Agro., Lab. Nutr. Sec. Alim., 78352 Jouy-en-Josas, France
Membrane incorporation of docosahexaenoic acid (DHA, 22:6n-3) during perinatal development is essential to proper functioning of brain and retina. Synthesis of DHA from its n-3 precursors requires a terminal peroxisomal step which
may be rate limiting. We examined whether DHA membrane incorporation is determined by the length and/or the concentrations of its metabolic precursors, by comparing the DHA contents in the phospholipids from neuroblastoma
cells cultured with preformed DHA or with graded doses of one of the upstream precursors. Human neuroblastoma cells ( SH-SY5Y) were cultured for 3 days in a medium supplemented with 18:3n-3, 22:5n-3 or 22:6n-3 (concentration
range: 7 to 70 µM), and the fatty acid compositions in phospholipids (EPG and PC) were analyzed. Incorporation of DHA was 3 times higher with preformed DHA than with 18:3n-3 or 22:5n-3. Cells responded to graded external DHA
doses by a saturating curve of incorporation in EPG and PC, while upon incubations with the precursors, DHA incorporation peaked at 10 µM 18:3n-3 or at 30 µM 22:5n-3. Higher doses of both precursors decreased the DHA
content in EPG, while that of 20:5n-3 concurrently increased. We assume that DHA synthesis from 18:3n-3 or from 22:5n–3 was differently regulated at low and at high doses of precursor, the concentration threshold being specific for
each precursor. We suggest that phospholipid accretion of 20:5n-3, produced from 18:3n-3 conversion or from 22:5n-3 ?–oxidation, could be the hallmark of down-regulating events in DHA synthesis.
(13-8)
POLYUNSATURATED FATTY ACIDS IN HIPPOCAMPUS ASSOCIATED WITH MEMORY IN SAMP8 MICE
A.L.Petursdottir1, S.A.Farr2, J.E.Morley2, W.A.Banks2, G.V.Skuladottir1. 1Department of Physiology, University of Iceland.
2Geriatric Research Education and Clinical Center (GRECC), VA Medical Center, St. Louis, Missouri, USA
The SAMP8 mouse has shorter median lifespan, and earlier manifestations of aging such as learning disability and loss of memory than a normal mouse. Late in life SAMP8 mice develop amyloid plaques in the hippocampal region of
brain that has been linked to neuronal death and consequently the Alzheimer disease pathology. It has been shown that a drug (antisense) directed to the β-amyloid region of the amyloid precursor protein (APP) gene reverses the
behavioural impairments in SAMP8 mice. The objective of this study is to investigate the fatty acid composition of phospholipids (PL) in SAMP8 mice hippocampus in relation to learning and memory deficits and the β-amyloid plaque.
Classes of PL were analysed from 12 month SAMP8 mice treated with antisense directed at the β-amyloid region of the APP peptide, random antisense, and 4 and 12 month untreated controls. The results indicate that in 12 month old
mice, docosahexaenoic acid (DHA) levels were lower in phosphatidylethanolamine (PE) as well as in phosphatidylserine (PS), compared to 4 month old mice. Furthermore, arachidonic acid (AA) levels were lower in PE
and phosphatidylinositol (PI) of 12 month old mice compared with 4 month old. Antisense directed to the APP gene seems to reverse the age related changes of DHA and AA in these PL. These preliminary results indicate that loss of
PUFA in neuronal cell membrane PL might be associated with learning and memory deficits in the SAMP8 mice.
(13-9) EFFECTS OF CERTAIN ANTICONVULSANTS USED TO TREAT BIPOLAR DISORDER ON ARACHIDONIC ACID METABOLISM IN AWAKE RATS
Richard P. Bazinet, Sandra Ghelardoni, Ho-Joo Lee, Lisa Chang, Jane Bell, Francesca Bosetti, and Stanley I. Rapoport
National Institutes of Health, National Institute on Aging, Brain Physiology and Metabolism Section Bethesda, MD, USA
Lithium is a drug effective in the treatment of bipolar disorder (BD) and valproate is an anti-epileptic drug (AED) also effective in the treatment of BD. Both drugs have both been shown to decrease the turnover of arachidonic acid (AA)
in the brain of the awake rat. We therefore studied the effects of other AEDs (topiramate [TPM]: not used for BD and carbamazepine [CBZ]: effective in BD) to see if decreased turnover of AA is a specific target of drugs effective in BD.
Rats were chronically treated with either TPM, CBZ or the appropriate control and infused with [1-14C] AA. We then applied our in vivo fatty acid model to examine the turnover of AA in the brain of the awake rat. TPM treated rats had
no change in the unidirectional incorporation coefficient and the rate of AA incorporation from plasma into brain phospholipids. TPM treatment did not change the net incorporation rate of AA from brain AA-CoA into phospholipids or
the turnover of AA in brain phospholipids. Results of CBZ treatment are in progress.
(13-10) NIACIN SKIN FLUSH RESPONSE IN DYSLEXIA
E.Cyhlarova, A.Shrier, M.A.Ross and A.J.Richardson, University Lab. of Physiology, Oxford, UK
The niacin skin test reflects a prostaglandin mediated flush and oedema reaction owing to the production of prostaglandin D2 from arachidonic acid. A diminished response to niacin may indicate potential abnormalities in
membrane phospholipid pathways, and this has repeatedly been shown in schizophrenia. There is evidence that dyslexia may also involve phospholipid abnormalities, but niacin flushing has not yet been
investigated in this condition. Our aim was to test the hypothesis that dyslexic adults would show reduced skin flushing responses to niacin compared with controls.
The niacin test was performed on 51 dyslexic adults and 45 age- and sex-matched controls. Four different concentrations of aqueous methyl nicotinate were applied topically to the inner forearm. Flushing responses were
assessed visually at 3 min intervals over 21 minutes and rated using a seven-point scale at each time-point. Repeated measures ANOVA for the 4 concentrations across all 7 time-points showed no significant effect of subject
group, but when analyses were confined to the first 9 minutes, flushing was weaker in dyslexic subjects. Significant group differences were also found for the lowest niacin concentration (0.0001 M) across all 7 time-points.
These results indicate a slightly reduced and delayed response to niacin in dyslexia, suggesting that this metabolic pathway deserves further investigation.
(13-11) THE FATTY ACID COMPOSITION OF SELECTED BRAIN REGIONS IN THE FLINDERS
SENSITIVE LINE RAT MODEL OF DEPRESSION COMPARED TO CONTROLS
Green P. 1, Gispan-Herman, I. 2, and Yadid G. 2,1The Laboratory for the Study of Fatty Acids, The Felsenstein Center for Medical Research, The Sackler School of Medicine,
Tel-Aviv University, Beilinson Campus, Petah Tikva, 2Neuropharmacology Section, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan
Polyunsaturated fatty acids (PUFA) are essential components of neuronal membrane phospholipids. The two PUFA are docosahexaenoic acid (DHA) of the omega-3 family and arachidonic acid (AA) of the omega-6 family. Several
studies document a negative relationship between the erythrocyte membrane phospholipids omega-3 PUFA content and depression. However, the pathogenetic significance of this finding in not known, because diet can affect
erythrocyte PUFA composition. Further, it is not universally accepted that erythrocyte and brain fatty acid composition are correlated. In the present study, we compared the brain fatty acid composition in the Flinders Sensitive Line (FSL)
rat model of depression and control rats. Both FSL and control rats were fed identical diets. The regions examined were hypothalamus, nucleus accumbens, prefrontal cortex and striatum. AA in the FSL rats was significantly higher
than in the controls (results are expressed as weight% of total FA, mean±SD; FSL vs. control): hypothalamus: 11.69±0.39 vs. 9.67±0.51, p=0.0002; nucleus accumbens: 15.00±0.70 vs. 12.05±0.53, p=0.0001; prefrontal cortex:
15.38±0.97 vs. 11.78±0.42, p=0.0004; striatum: 12.60±0.37 vs. 10.28±0.52, p=0.0005. DHA concentrations were lower in FSL rats compared to controls, but the 3-11% difference did not reach significance. These results are in agreement
with the “phospholipid hypothesis” of depression, inasmuch as significant brain PUFA differences were observed, clearly not related to dietary composition. These somewhat unexpected results may explain the reported beneficial
effects of EPA supplementation in depresssive patients and open new avenues of investigation into the pathophysiology of depression.
(13-12)
LIPOPHILIC-POLYCATIONIC CARRIER-BASED DELIVERY OF BIOMOLECULES TO THE BRAIN
Robert Katz1, Mario C. Rattazzi2 and Paul Fishman3,1Omega-3 Research Institute, Inc., Bethesda, Maryland, USA, 2Long Island, New York, USA and 3University of Maryland School
of Medicine and VA Medical Center, Baltimore, Maryland, USA
A new approach has been developed for the potential delivery of biomolecules to the brain. The approach utilizes a carrier composed of a relatively short chained polylysine molecule (preferably containing between 5 and 50 (L)-lysine
units) conjugated to two or more long chain omega-3 polyunsaturated fatty acid moieties (eicosapentaenoic acid, EPA, 20:5n-3 or docosahexaenoic acid, DHA, 22:6n-3) at the epsilon-amine position. The molecule(s) to be carried to the
cerebrovascular endothelium for delivery, binding to the endothelium and transport through the blood-brain barrier are attached to these lipophilic-polycationic carriers.
Deca-L-lysine monodocosahexaenoate and deca-L-lysine didocosahexaenoate were prepared and tagged with Texas- Red. Deca-L-lysine was labeled with flurescein to serve as control. The conjugates were purified and identified by
mass spectral analysis. Rats were anesthetized, their carotid arteries exposed and a solution of the two conjugates and the control in calf serum was injected into the exposed carotid artery. The rats were sacrificed, the brains
removed, placed in dry ice and frozen. Thin sections from the cortex were examined in a fluorescent microscope. Fluorescent slides will be presented to demonstrate binding of the conjugates to the endothelium in sections of the
frontal cortex.
(13-13) IMPROVEMENT OF MAJOR DEPRESSION IS ASSOCIATED WITH INCREASED
ERYTHROCYTE DHA - SUBSET ANALYSIS IN A DOUBLE-BLIND OMEGA-3 SUPPLEMENTATION TRIAL
BJ Meyer 1,3, B Grenyer2, T Crowe2, AJ Owen3, PRC Howe4,1Dept of Biomedical Science, 2Dept of Psychology and 3Smart Foods Centre, Univ of Wollongong, NSW 2522; 4Nutritional
Physiology, Univ of Adelaide & Univ of South Australia, SA 5005, Australia
The aim of this study was to examine the possible inverse relationship between w-3 fatty acid intake and depression. A total of 95 volunteers receiving treatment for major depression were randomised to consume 8 x 1g capsules per day
of HiDHA tuna oil (2g DHA, 0.6g EPA and 10mg Vit E) or olive oil (placebo) for 4 months, whilst undergoing weekly counselling sessions by trained clinical psychologists using a standard empirically validated psychotherapy.
Depression status was assessed using the 17-item Hamilton Rating Scale for Depression, Beck Depression Inventory and Global Assessment of Functioning Scale, by a psychodiagnostician who was blind to the treatment. Blood was
taken at 0 and 4 months for measurement of erythrocyte fatty acids from a subset of 48 (24 on each treatment) who met the primary diagnosis of major depression according to DSM-IV.
With HiDHA supplementation, erythrocyte DHA content rose from 4.2 ± 0.2% to 7.9 ± 0.4% (mean ± SEM, p<0.001) of total fatty acids but did not change (4.2 ± 0.2% to 4.1 ± 0.2%) in the olive oil group. The mean changes in scores of
depression did not differ significantly between the two groups (-12.2 ± 2.1 for tuna oil and –14.4 ± 2.3 for olive oil). However, analysis of covariance showed that in both groups there was a significant association between the change in
erythrocyte DHA and the change in scores of depression (p<0.05). Further study of the relationship between DHA and depression is warranted.
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MALLEABILITY OF BRAIN DHA IN DEPLETION AND REPLETION PARADIGMS
Toru Moriguchi1, James Loewke2, Norman Salem Jr. 2,1 Healthcare Research Institute, Wakunaga Pharmaceutical Co., Ltd., Japan
2 National Institutes on Alcohol Abuse & Alcoholism, NIH, USA
This work provides data relevant to the questions of the rate of DHA depletion when weanling or young adult mice are subjected to an n-3 deficient diet and also the rate of recovery of the brain when mice are fed a repletion diet
subsequent to n-3 deficiency. In the first experiment, ICR strain, male mice were obtained at 3 wks of age after being fed a commercial diet containing both alpha-linolenate and DHA. They were maintained on the n-3 Adq diet containing
only alpha-linolenate as n-3 fatty acids source. At either 3 or 7 weeks of age, the pups were then switched to a safflower oil based diet that was very low in sources of n-3 fatty acids (n-3 Def diet). The results showed a progressive
decline in brain DHA with much the same slope at the two ages. After 10 weeks the brain DHA had declined to 12 and 12.8%, respectively, for the groups given the n-3 Def diets beginning at 3 and 7 weeks and a concurrent increase in
the DPAn-6. It was of significance that the young adult mouse could lose DHA at such a great rate at an age where brain growth had plateaud. In the second experiment, n-3 Def mice were switched to an n-3 Adq diet at either 3 or 7
wks of age. There was a rapid and progressive increase in brain DHA and a decline in brain DPAn-6 in both groups. However, the 3 wk group recovered more quickly with a half time of only 1.5 wks for DHA whereas the 7 wk group had
a half-time of 3.8 wks, nearly twice as long. This result may be due to a faster rate of transport of DHA into the weanling brain relative to the young adult.
(13-15) SHORT-TERM DIETARY MENHADEN FISH, SEAL & CORN OILS DIFFERENTIALLY AFFECT
CHOLESTEROL, LIPID PEROXIDES AND POLAR LIPID FATTY ACIDS IN GUINEA PIG BRAIN
M.G. Murphy1, V. Wright1 & R.G. Ackman2, Depts. of 1Physiology & Biophysics and 2Food Science & Technol., Dalhousie University, Halifax, Nova Scotia, Canada
Young albino guinea pigs, which are relatively deficient in n-3 PUFA, were fed either a nonpurified diet (NP) or diets containing (10%, w/w) menhaden fish (MO), seal (SLO), or corn (CO) oils for 4 weeks. Brain TAG levels were unaltered
by diet; however, total cholesterol was reduced with the oil-enriched diets relative to those in NP-fed animals. Lipid peroxide values (nmol/mg protein) were 1.4, 1.0 & 0.6 for the MO, CO and SLO brains, respectively). Analysis of brain
polar lipid fatty acids indicated that animals fed marine oils had lower n-6/n-3 PUFA ratios (MO=1.0; SLO=1.4) than those given CO (2.5) or NP (2.4). The two marine-oil diets differentially altered n-3 PUFA profiles, as DHA/EPA ratios
were 14.5 & 47.5 in brains of MO- and SLO-fed animals, respectively. This study demonstrated that select lipid components of guinea pig brain are altered by marine-oil-rich diets in a short time, and that the specific changes
elicited are dependent upon the source of marine oil. Supported by the Canadian Heart & Stroke Foundation, and Gateway Maritime Inc.
(13-16) LITHIUM MODULATES NEUROTRANSMITTER-INITIATED ACTIVATION OF
PHOSPHOLIPASE A2 (PLA2) IN RAT BRAIN IN DIFFERENT WAYS, DEPENDING ON RECEPTOR SUBTYPE
M. Basselin, L. Chang, R. Seemann & S. I. Rapoport*. Brain Physiology and Metabolism Section, National Institute on Aging, NIH,
Bethesda, MD, USA
Li+ is widely used to treat bipolar disorder, but its mechanism is not agreed on. We hypothesized that Li+ corrects a disease-related imbalance in neurotransmission by receptor-mediated activation of PLA2. To test this, we used our
fatty acid method1 and injected [1-14C]arachidonic acid (AA) i.v. in awake rats fed Li+ for 6 wk. After 20 min, we measured brain radioactivity by quantitative autoradiography in response to low nonconvulsant doses of the cholinergic
muscarinic M1,3,5 receptor agonist, arecoline; the serotonergic 5-HT2A/2C receptor agonist, DOI; the dopaminergic D2 receptor agonist, quinpirole. Li+ potentiated regional brain values of k*, representing AA incorporation (brain
radioactivity/integrated plasma radioactivity) into the sn-2 position of phospholipids and thus PLA2 activation, in response to arecoline2, did not markedly change k* responses to DOI, while blocking k* responses to quinpirole. These
results may explain some of Li+'s therapeutic action, as bipolar disorder is considered to involve reduced brain cholinergic compared with excess dopaminergic neurotransmission. They suggest that Li+ can have different effects on
receptor-initiated PLA2 signaling at the level of the PLA2 enzyme family or of G proteins that couple PLA2 to the receptor. REF: 1Rapoport J Mol Neurosci 16, 243, 2001; 2Basselin J Neurochem 85, 1553, 2003.
(13-17)
WORKING MEMORY AND SCHIZOTYPAL TRAITS IN RELATION TO FATTY ACID STATUS IN DYSLEXIA
M.A.Ross,1 E.Cyhlarova,1 A.Shrier,1 R.J.Henderson,2 E.MacKinlay, 2 J.R.Dick,2 J.G.Bell2 and A.J.Richardson.1,1University Lab. of Physiology, Oxford, 2Institute of Aquaculture, Stirling University, Scotland, UK
There is already evidence for fatty acid abnormalities in dyslexia, which involves specific weaknesses in working memory and has also been linked with certain ‘positive’ schizotypal traits. Our aim here was to investigate both working
memory performance and these personality traits in relation to n-3 and n-6 fatty acid status. 30 dyslexic adults and 19 matched controls completed the OLIFE inventory of schizotypal traits and a standard working
memory test (WAIS-R Digit Span). The polar lipid composition of RBC membranes was determined from venous blood samples, and non-parametric correlations were used to examine relationships between n-3 and n-6 concentrations and
psychological measures. As expected, dyslexic subjects showed poorer working memory (p < 0.0001) and higher schizotypy scores (p < 0.001)
than controls. Within dyslexia, these features were strongly inter-correlated and associated with lower EPA concentrations and higher AA/EPA ratios (all p < 0.05) as well as higher total n-6 status. In controls, schizotypy did not
relate to working memory nor fatty acid status, but better working memory was associated with higher total n-6 (p < 0.05) and a trend towards lower EPA, i.e. correlations were in the opposite direction to those found in dyslexic
subjects. These findings merit further investigation, but are consistent with the idea that treatment with n-3 fatty acids (and
particularly EPA) may benefit some individuals with dyslexia, currently under investigation via controlled trials.
(13-18) INFLUENCE OF N-3 FATTY ACID INTAKE ON DIHYDROXYACETONE PHOSPHATE ACYL
TRANSFERASE (DHAP-AT) ACTIVITY AND IN SITU HYBRIDIZATION IN THE RAT BRAIN
A. Andre1, J.M. Chardigny1, C. Tessier2, L. Bretillon1.,1 INRA, Unité de Nutrition Lipidique, Dijon, France.
2 UPRES Lipides et Nutrition, Université de Bourgogne, Dijon, France
DHAP-AT is a peroxisomal enzyme involved in the synthesis of plasmalogens (Pl), a subclass of phospholipids characterized by a vinyl ether bond at the sn-1 position of the glycerol backbone. Pl represent between 1/2 and 2/3 of the
ethanolamine phospholipids in the brain and are known to be reservoirs of polyunsaturated fatty acids and efficient antioxidants in vitro. Since DHAP-AT has been reported to be up-regulated by docosahexaenoic acid (DHA), we aimed
to evaluate whether the precursor of DHA (α-linolenic acid, αLNA) alone or with DHA may regulate DHAP-AT activity and mRNA localization in the rat brain. For that purpose, littermates from 2 generations of n-3 deficient animals were
fed an equilibrated standard diet containing either αLNA alone (2.5% of the lipids) as the sole source of n-3 or αLNA with 2 doses of DHA (0.3 or 0.6% of the lipids). After 9 months of diet, DHAP-AT activity in the brain was similar in the
3 groups of animals (between 0.061 and 0.071 nmol acyl-DHAP formed/µg protein). Noticeably this value was from 7 to 8 times lower than in the liver (0.47). The localization of DHAP-AT mRNA in the brain by in situ hybridization showed
a weak signal which magnitude was again much lower than in the liver. We conclude from this study that DHAP-AT expression and activity in the brain may unlikely be affected by dietary DHA. In addition, accounting the differences we
observed in the brain and in the liver, we postulate that most of the Pl in the brain may be of liver origin.
14. Obesity and Insulin Resistance and Metabolic Syndrome
(14-1) N-3 FATTY ACIDS AND INSULIN SENSITIVITY IN NEWLY DIAGNOSED TYPE 2
DIABETICS
1P Gothard, 2B Thomas, 1C Lowy, 1R Aurora 2K Ghebremeskel and 2MA Crawford. 1Endocrine & Diabetic Day Centre, Guy’s & St.
Thomas’ Hospital Trust, London. 2Institute of Brain Chemistry & Human Nutrition, London Metropolitan University, London, UK
Insulin insensitivity and hyperglycaemia characterise Type 2 diabetes, and are associated with reduced membrane docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. We have piloted a study to investigate if supplementation
with n-3 fatty acids enhances insulin sensitivity by correcting membrane fatty acid composition. Sixteen (n=16) diet treated Type 2 diabetics were randomized to receive 10g/d of fish oil (MaxEPA) or olive oil capsules for 8 weeks.
Insulin sensitivity and body weight did not differ in either group. The fish oil treated group reduced plasma triglylcerides (-0.51 mmol/l), body fat (-3.74 kg; p<0.05), and had an insignificant gain in lean body mass (+4.86 kg). There was
an increase in EPA (p<0.01), docosapentaenoic (DPA; 22:5n-3) and DHA (p<0.01) in red cell choline and ethanolamine phosphoglycerides. These preliminary data indicate that supplementation with n-3 fatty acids even for a
short period may benefit newly diagnosed diabetics. However, a longer supplementation period may be necessary to change muscle composition and influence insulin sensitivity.
(14-2) PLATELET MEMBRANE PHOSPHOLIPID FATTY ACIDS ARE WEAKLY ASSOCIATED
WITH MARKERS OF INSULIN RESISTANCE AND SOME CVD RISK FACTORS
Julie A Lovegrove, Louise M Brady, Sean S Lovegrove, Stephanie VM Lesauvage, Anne-Marie Minihane, Christine M Williams
School of Food Biosciences, University of Reading, UK
The measurement of membrane fatty acids is now recognised as a useful marker for CVD risk. A low n-3 PUFA index (EPA and DHA in red blood cell membranes) was associated with an increased risk of CVD. The aim of this study was
to determine the association between platelet membrane phospholipid fatty acids and a marker of insulin sensitivity and CVD risk factors. 109 healthy UK Indian Asians and Caucasians (mean age 48±11 years) were recruited. A fasted
blood sample was drawn and plasma insulin, glucose, total, HDL and LDL-cholesterol, triacylglycerol, non-esterified fatty acids, apolipoprotein B-48 (apoB-48) and C-reactive protein were analysed. The revised quantitative insulin
sensitivity check index (rQUICKI) was calculated as a marker of insulin sensitivity. Platelet membrane phospholipid fatty acids were measured and correlated with the biochemical parameters measured. All correlations were weak,
although the Indian Asians had stronger associations than Caucasians. rQUICKI was negatively associated with SFA (r=-0.239) and MUFA (r=-0.474); yet positively with n-6 PUFA (r=0.420) and n6:n3 PUFA ratio (r=0.208). Plasma apoB-
48 was positively correlated with SFA (r=0.352), MUFA (r=0.460) and negatively with n-6 PUFA (r=-0.496). HDL cholesterol was positively associated with n-3 PUFA (r=0.213), yet negatively with n6:n3 PUFA ratio (r=-0.210). High
membrane SFA was weakly associated with lower insulin sensitivity and high PUFA with higher insulin sensitivity (n-6 PUFA) and higher HDL levels (n-3 PUFA).
(14-3) INCREASED GLUCOSE OXIDATION IS INVOLVED IN THE STIMULATORY EFFECT OF
EPA ON LEPTIN SECRETION IN PRIMARY CULTURED RAT ADIPOCYTES
Patricia Pérez Matute1, Amelia Marti1, J. Alfredo Martínez1, Kimber L. Stanhope2, Peter J. Havel2 and María J. Moreno-Aliaga1
1 Department of Physiology and Nutrition. University of Navarra, Pamplona, Spain,2 Department of Nutrition. University of California, Davis, USA
Eicosapentaenoic acid (EPA), one of the n-3 PUFAs, has been shown to prevent the development of insulin resistance and diabetes in several models of obesity. Previous studies of our group have shown that EPA upregulates leptin, a
hormone secreted by white adipose tissue and implicated in the regulation of body weight. However, the underlying mechanisms remain unknown. Several studies have suggested that glucose utilization stimulates leptin production by
directing the metabolism of glucose to oxidation. For this purpose, the effects of EPA on leptin production, glucose and lipid metabolism were studied in primary cultured rat adipocytes. Similar to insulin, EPA (10, 100 and 200 µM)
increased basal leptin secretion and glucose uptake. It also activates the insulin-stimulated leptin secretion, although the effects were not as potent as in absence of insulin. EPA (200 µM) induced a significant increase in the proportion of
glucose oxidized to CO2. On the contrary, the percentage of glucose released as lactate, which has been shown to be inversely correlated to leptin secretion, was significantly decreased by EPA treatment. EPA also decreased the amount
of glucose incorporated into triglyceride (lipogenesis), while no effects were observed on lipolysis, assessed as the amount of glycerol released to the media. These results suggest that the increase in leptin induced by the EPA could
be mediated, at least in part, by an activation of the glucose oxidation pathway.
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LIPID PROFILING AS A TOOL FOR CHARACTERIZING ANIMAL MODELS IN STUDIES OF METABOLIC DISEASES
Matej Oresic1, Tuulikki Seppänen-Laakso1*, Samuel Aparicio2, Gema Medina3, Antonio Vidal-Puig3,*Presenting author
1VTT Biotechnology, Tietotie 2, Espoo, FIN-02044 VTT, Finland, 2Paradigm Therapeutics, UK
3Cambridge University, Addenbrooke’s Hospital, UK
Multifactorial diseases such as Type 2 Diabetes or Metabolic syndrome are presenting a significant challenge to functional genomics and proteomics approaches.
We are developing a platform that will enable us with phenotype characterization of animal models in the context of studies of metabolic diseases. For that purpose, we have developed a platform for lipid profiling using LC/MS
technology. The analytical platform is set up so that a broad range of lipid classes is covered within a single sample run, and it is the role of computational approaches to deconvolve the complex spectra and compare the profiles
between different samples. Various pattern recognition methods are applied to spectral data in order to develop markers of specific physiological responses, which can then be linked to information at metabolite, protein and
transcript levels in context of known biological processes. We aim to present our methodology, and as an illustration present recent studies of mouse models in studies of
lipotoxicity and insulin resistance. Specifically we will present data related to the characterisation of the adipose tissue, liver, and skeletal muscle of a PPAR? related mouse model. PPAR? is a nuclear receptor involved in adipogenesis and
insulin sensitivity. Furthermore PPAR? is the receptor of thiazolidinediones, insulin sensitizers used in the treatment of diabetes. Our studies attempt to correlate the transcriptome, proteome, and metabolome of this mouse model with its
metabolic phenotype.
(14-5)
MATERNAL DIETARY TRANS FATTY ACIDS DECREASE GLUT4 PROTEIN LEVELS IN THE SUCKLING CARDIOMYOCYTES DURING POSTNATAL DEVELOPMENT
Osso, FS1; Moreira ABS1; Rocha ASC1; Costa CL2; Tavares do Carmo, MG3; Sanchez Moura A1. Instituto Biomédico1/ Depart.
de Nutrição Aplicada2,Universidade do Estado do Rio de Janeiro; Instituto de Nutrição3-Universidade Federal do Rio de
Janeiro, Brazil
Glucose is an important fuel for heart development. High glucose uptake during postnatal development is coincident with the highest expression of the GLUT-4 glucose transporter in neonatal rat cardiomyocytes. Glut-4 expression is
primarily regulated by insulin. Several epidemiological and experimental studies suggest that a rich trans fatty acids diet affects insulin sensitivity. The aim of the present study was to determine the GLUT4 content in cardiomyocytes of
suckling rats, whose mothers were fed with partially hydrogenated fat - high in trans fatty acids - during lactation. From d 0 of lactation, females Wistar rats were divided into two groups (n=6 pups/group) and fed with purified isocaloric
diets that differed only in their lipid source. One diet contained 9%of soy oil (Control Group) and the other contained 7% of partially hydrogenated vegetable oil (PHVO) plus 2% soy oil (Group PHVO) in order to provide the adequate
essential fatty acids content. Body weight was measured and the GLUT4 was assessed by Western blotting in cardiomyocytes of the suckling rats on d 14 of lactation. We observed that there were no significant difference in the
body weight of pups between the experimental groups during the studied period. However, in the PHVO group was observed that the GLUT4 content was reduced in cardiomyocytes (by 50%) when compared with Control Group. Our
data suggest that a mother’s diet, rich in trans fatty acids, may induces insulin resistance in the heart of suckling rats. Supported by: CNPq, FUJB; FAPERJ
(14-6) VISCERAL ADIPOSE LOSS AND QUANTITATIVE LIPID METABOLITE DIFFERENCES
FROM A DAIRY MULTI-CENTER WEIGHT LOSS TRIAL
Jennifer T. Smilowitz, Tim Radak, Steve M. Watkins*, J. Bruce German and Marta Van Loan, Department of Nutrition, University of California, Davis, CA 95616 and *Lipomics Technologies, Incorporated,
West Sacramento, Ca 95691
Data from both animal and clinical studies demonstrate anti-obesity effects of dairy consumption. When diets of aP2- agouti transgenic mice were supplemented with calcium or calcium-rich dairy products, significant weight and fat loss
was demonstrated. Several clinical trials have revealed a negative association between dairy product consumption and total body fat. In this multi-center trial, we have examined the effects of increasing calcium and dairy product intake on
visceral fat during a 12 week 500 calorie deficit dietary intervention in overweight individuals. Visceral adipose was measured at baseline and 12 weeks by waist circumference and sagittal diameter, and trunk fat was determined by
dual-energy X-ray absorptiometry (DEXA). Intraabdominal adipose tissue (IAAT) was estimated using a stepwise regression analysis based on DEXA and anthropometric variables. In addition, quantitative lipid metabolite data was
generated for lipid classes and their constituent fatty acids using high performance liquid chromatography (HPLC) and gas chromatography (GC). Compared to placebo, subjects in the high dairy group demonstrate greater loss of
visceral adipose tissue.
(14-7)
INCREASED FATTY ACID AND GLUCOSE METABOLISM IN CULTURED HUMAN MYOTUBES AFTER TREATMENT WITH THE LIVER X RECEPTOR (LXR) AGONIST
T0901317
Wensaas A, Kase ET, Aas V, Rustan AC, Thoresen GH, Højlund K*, Levin K*, Beck-Nielsen H* and Gaster M*,Dept. of Pharmacology, University of Oslo, Norway
*Dept. of Endocrinology, Odense University Hospital, Denmark
Little is known about the role of the LXRs in skeletal muscle. We investigated the effects of T0901317 on lipid and glucose metabolism in myotubes from type 2 diabetics (T2D) and healthy controls. Differentiated myotubes were
exposed to T0901317 for 4 days, and then incubated for 4 h with [14C]palmitic acid (PA), [14C]glucose or [3H] deoxyglucose. T0901317 increased PA uptake by 50 % (45 nmol/mg protein) in control myotubes. Interestingly, the
increment was 31 % higher (59 nmol/mg protein) in T2D myotubes. PA incorporation to DAG and TAG was 2-fold increased in control cells, whereas T2D myotubes showed an additional 70-80 % increase. T0901317 induced PA
oxidation to CO2 by 22 %. This effect was absent for T2D cells. Insulin-stimulated glucose transport tended to increase, while glucose oxidation was increased by 65 % after T0901317. No differences were found in glucose metabolism
between T2D and control myotubes. The mRNA expression was up regulated after T0901317: CD36 (2-3-fold), ACS-2 (3-fold), GLUT4 (6-fold), LXR? (8-fold) and PPAR? (3-fold). LXR? was 50 % higher in control myotubes only. Our data
show that chronic T0901317 increases lipid accumulation in human myotubes. The effect is stronger in T2D than control myotubes, and this might involve an absent increase in lipid oxidation. Moreover, T0901317-incubation has a
positive effect on glucose metabolism for both groups. These findings might imply that dysregulation of the LXR pathway could be attributing to the high intramyocellular TAG found in T2D.
(14-8) LIPOPROTEIN LIPASE MODULATOR AS A POSSIBLE DRUG AGAINST OBESITY AND
METABOLIC SYNDROME?
J. Bailly, I. Kunz, N. Panday, S. Raab, W. Schilling, Metabolic disease department Hoffmann LaRoche AG Basel CH
Lipoprotein lipase (LPL) is an enzyme which hydrolyses plasmatic triglycerides (PT) coming from VLDL particles and chylomicrons. This enzyme is mainly produced in muscle and adipose tissues and is driving fatty acid storage in
adipocyte or oxidation in muscle. Its over-expression in adipose tissue has been linked with a predisposition to obesity. LPL stimulation should increase fatty acid oxidation (muscle) and decrease PT. NO-1886 (I) has been described to
increase LPL mRNA as well as LPL activity in vivo. Animals treated with (I) have a reduced body weight (BW) and respiratory quotient (RQ) suggesting an increase of muscular fatty acid oxidation (for review see Cardiovascular-Drug-
Reviews (2003),21(2),133-142). (I) has been tested in vivo acutely in an indirect calorimetry system and chronically on a DIO rat model. Drug exposure
has been monitored. Although animals have been exposed to the drug no impact on BW, food intake, energy expenditure, RQ and PT have been observed. The discrepancies between our results and the already published
results have to be further clarified.
(14-9) EFFECT OF INCREASED INTAKE OF DIETARY CARBOHYDRATES IN INUIT ON
TRADITIONAL DIETS RICH IN OMEGA-3 FATTY ACIDS
Bélanger MC1,2, Dewailly E3, Berthiaume L1, Mirault ME2, Julien P1,
1Lipid Research Center, 2Health and Environment & 3Public Health, CHUL Research Centre, Ste-Foy, Qc, Canada
Methods: A study was conducted in 95 apparently healthy Inuit of Nunavik in whom clinical data were obtained.Background: Epidemiological studies revealed that Inuit had much lower prevalence of ischemic heart disease (IHD) and type II diabetes than other indigenous communities probably due to the consumption of ocean-derived oils rich in
n-3 polyunsaturated fatty acids (PUFAs). Objective: Reevaluate, eight years after an initial health survey carried out in Inuit of Nunavik, various risk factors
related to cardiovascular diseases in order to assess the effects of n-3 PUFAs in combination with increased intake of dietary carbohydrates. Fasting plasma lipoprotein profiles, insulinemia, glycemia and erythrocyte fatty acid composition were analyzed using
standard automated methods and gas-liquid chromatography. Results: Plasma lipid and apoprotein concentrations were similar to levels found in the previous study and were
characterized by normal lipid profiles and low concentrations of plasma free fatty acids despite significant obesity (BMI > 31.0 kg/m2). However, we now report a severe emergence of hyperinsulinemia among 46.3% of participants. In
obese subjects, an inverse correlation between n-3PUFAs and the levels of plasma VLDL-triacylglycerols was found. Surprisingly, elevated concentrations of n-3PUFAs were also correlated with increased glycemia in obese subjects.
Conclusion: These data indicate that elevated intake of carbohydrates in combination with a traditional diet rich in n- 3PUFAs could have significant adverse effects on the plasma levels of glucose and the resulting expression of type II
diabetes in Inuit.
(14-10)
THE EFFECT OF ERABU SEA SNAKE OIL INTAKE ON THE BLOOD GLUCOSE LEVEL AND INSULIN SECRETION IN MICE
Tomoyuki Higuchi1, Nobuya Shirai1, Hiramitsu Suzuki1 and Reiko Shimizu2,1National Food Research Institute, Kannondai, Tsukuba, Ibaraki, Japan; 2Fuji Pharmaceutical Inc., Kamimeguro, Meguro,
Tokyo, Japan
Erabu sea snake (Laticauda semifasciata), a marine reptile, is distributed throughout the Pacific Ocean and along the coast of the South China Sea. The aim of this study was to clarify the effect of dietary Erabu sea snake oil, enriched in
n-3 polyunsaturated fatty acids, on glucose (Gl) and lipid metabolism. Male Crj:CD-1 mice were fed the experimental diets which contained 6% lard, 6% fish oil, or 6% Erabu sea snake oil for 17 weeks. Plasma total cholesterol (T-chol)
levels were significantly lower in the sea snake oil diet group than in the lard diet group at Week 6. Plasma phospholipid (PL) levels of the sea snake oil diet group tended to be lower than those of the lard diet group during
Weeks 2-8, and were significantly less during Weeks 12-16. Plasma PL levels of the fish oil group were significantly lower than those of the lard group during Weeks 2-16. Blood Gl levels were significantly lower in the sea snake oil diet
group than in the lard diet group at Week 16. From these findings it would appear that the decrease in blood Gl levels of the mice fed sea snake oil is later than the decrease in plasma lipid levels. There were no differences in blood Gl
and insulin levels between the sea snake oil and lard diet groups in streptozotocin-treated and normal mice as ascertained by a Gl tolerance test. These results suggest that the decrease in blood Gl levels following an intake of sea
snake oil is associated with the decrease in plasma lipids, but not insulin secretion.
(14-11) MEMBRANE LIPID IMBALANCE IN LEAN WOMEN WITH GESTATIONAL DIABETES
FROM SOUTH KOREA
Min Y1, Ghebremeskel K1, Nam JH2, Kim A2, Crawford MA1,1Institute of Brain Chemistry and Human Nutrition, London Metropolitan University, London, UK
2Asan Medical Centre, University of Ulsan, Seoul, South Korea
Gestational diabetes (GDM) is a transient metabolic disorder characterised by insulin resistance and lipids abnormality. It is a strong predictor of Type 2 diabetes and cardio-vascular disease. The prevalence of GDM in South Korea is 2%,
however 38% of these women are expected to have persistent glucose intolerance early postpartum. Hence, we examined the fatty acids status of women with GDM (n=12) and compared with age-/BMI-matched women with
normoglycaemia (control). Blood was taken at delivery and fatty acids were analysed for plasma triglycerides (TG), cholinephosphoglycerides (CPG), sphingomyeline (SPH) and red cell CPG, ethanolaminephosphoglycerides (EPG)
and SPH. The mean pre-pregnancy BMI of all participants were 21. The fatty acids profile of the plasma TG and CPG was similar between the GDM and controls. Conversely, the GDM had reduced levels of n-6 and n-3 metabolites in the
red cell CPG and EPG. Interestingly, the SPH of the plasma and red cells were differently affected in the GDM as the saturated and monounsaturated fatty acids in the plasma were reduced whilst no changes were found in the red cells.
The dissimilarity between the plasma and membrane fatty acids profile suggests that the development of GDM might be associated with altered fatty acids metabolism.
(14-12) INCORPORATION OF WALNUTS INTO THE DIET INCREASES THE α-LINOLENIC ACID
CONTENT OF PLASMA TRIGLYCERIDES IN TYPE II DIABETICS
AJ Owen1, LC Tapsell1,2, MJ Batterham1, L Gillen2, C Patch2, M Baré1, ML Theiss1,1Smart Foods Centre & 2Dept. Biomedical Science, University of Wollongong, NSW, Australia
Fasting plasma triglyceride levels are a marker of postprandial lipemia, and risk factor for cardiovascular disease in obesity and type II diabetes (T2DM)1. Evidence exists for a positive effect of very long chain n-3 fatty acids (FA) on
plasma triglyceride levels, while the effects of α-linolenic acid are less established2. As the FA composition of triglycerides influence basal lipolysis3, changes to triglyceride FA composition, as well as absolute levels, may be
important. This study examined the effects of 30g/day of walnuts to achieve recommended dietary fat targets in T2DM subjects (n=17) over 6 months. Measures were taken at baseline, 3 and 6 months for determination of plasma lipids
levels and plasma triglyceride FA composition. The baseline characteristics (mean±SD) were: BMI=30.7±3.9 kg/m2, age 35-75 years, fasting plasma triglyceride
1.90±0.74mmol/l. Plasma triglyceride concentration did not change significantly over the study (1.70±0.68 at 6 months). However there were significant changes to triglyceride FA composition (expressed as % of total triglyceride
FA) with increases in ?-linolenic acid (0.90±0.41 vs 1.33±0.57) and n-6 polyunsaturates (34.97±6.62 vs 39.70±7.54) and decreases in total saturates (24.03±4.45 vs 21.79±4.07) between baseline and 6 months (p<0.05). Further
research is needed to determine the effect of these changes on postprandial hypertriglyceridemia.
(14-13)
MATERNAL DIETARY ESSENTIAL FATTY ACID DEFICIENCY REGULATES THE MRNA EXPRESSION OF LEPTIN RECEPTORS IN SUCKLING RAT PUPS
Palsdottir V1, Gabrielsson BG2, Korotkova M1, Strandvik B1,Depts of Pediatrics1 and Internal medicin2 Sahlgrenska Academy, Göteborg University, Göteborg, Sweden
Background: Previous studies have shown that essential fatty acid (EFA) deficiency in the diet during late pregnancy and lactation decreases leptin mRNA expression in adipose tissue and serum leptin levels of the suckling rat pups.
Leptin is a peptide hormone that in addition to its important role in the regulation of body weight also is associated with immune response. Leptin deficiency may in part be responsible for the immune impairment that accompanies
malnutrition. Aim: To investigate the leptin receptor gene expression in mesenteric lymph nodes and hypothalamus of 3 weeks old
rat pups, whose dams were fed with essential fatty acid deficient (EFAD) or control diet. Results: Real-time PCR analysis of leptin receptor (ObR) mRNA expression showed higher levels in mesenteric lymph
nodes from EFAD pups compared with control pups, 1.7 vs. 0.4 (p<0.01, n=6). In contrast, the expression pattern of
ObR in hypothalamus appeared to be reversed, (1.5 vs. 2.5, EFAD and controls, respectively), although this difference was not significant due to small sample group (n=4). All values were normalised to beta-2-microglobulin expression.
Conclusion: These data indicate that the regulation of leptin receptors in the rat is tissue specific and that EFA deficiency in the perinatal period can affect the expression of leptin receptors.
(14-14) EFFECTS OF SUPPLEMENTED DHA ON PHOSPHOLIPID DHA LEVELS IN INFERTILE
MALE SEMINAL PLASMA AND SPERM
G.V. Skuladottir1, S. Thorsteinsdottir2, A.L. Petursdottir1, B. Gisladottir1, A. Hauksson3 and H. Bjorgvinsson2.
1Department of Physiology, University of Iceland, 2IVF-unit, Department of Obstetrics and Gynaecology, Landspitali University Hospital, ,3Prenatal Care, Reykjavik Health Care Center, Iceland
Low docosahexaenoic acid (DHA; 22:6n-3) level in sperm has been associated with low total sperm number, reduced
motility and abnormal morphology. The objective of this study was to investigate the incorporation of DHA
supplementation into sperm. Thirteen infertile men (age 29-43 yr) consumed 6 capsules of EPAX 2050TG (Pronova Biocare a.s.), providing 810 mg of EPA and 2100 mg of DHA, daily for 20 weeks. Semen and blood samples were
collected at entry, after 10 and 20 weeks supplementation, and 10 weeks after termination of the supplementation. EPA and DHA where efficiently incorporated into blood plasma PL (p<0.001), and DHA was efficiently incorporated
into seminal plasma (p<0.001). The sperm DHA levels were 22.67±2.30 (mean ± SEM) at entry and 26.98±1.56 after 10 weeks supplementation. There was a positive correlation between DHA levels in seminal plasma PL and DHA
levels in sperm PL (r=0.568, p<0.001), as well as blood plasma PL (r=0.328, p<0.013). There was a relationship between DHA levels in sperm PL and total sperm count (r=0.669, p<001), and normal morphology (r=0.341, p=0.009).
There is an indication that incorporation of supplemented DHA into sperm PL is more efficient when the sperm PL DHA level is relatively low at entry. Furthermore, DHA levels in PL of blood plasma, seminal plasma and sperm reaches a
maximum plateau within 10 weeks of EPAX 2050TG supplementation.
(14-15) CHANGES IN PROTEIN AND FAT BALANCE OF PRIMARY FOODS: IMPLICATIONS FOR
OBESITY
Wang YQ, Thomas B, Ghebremeskel K and Crawford MA. Institute of Brain Chemistry and Human Nutrition (IBCHN),
London Metropolitan University, London, UK
We have compared the energy content of chicken over the last ten decades from the published data. The combined calorie of protein and fat of the edible portion of chicken was 107.4 in 1896 (USDA), 194.7 in 1953 (FAO) and 235.7 in
2002 (6th edition of McCance & Widdowson). Our recent finding is consistent with the 2002 value. The data reveal that edible chicken supplied twice the amount of calories in 2002 as compared to 100 years ago. This change in
calorie content of edible chicken is due to an increase in fat and a concomitant decrease in protein. Furthermore, our analysis indicates that the docosahexaenoic acid composition of chicken meats has decreased by about 60% since the
1980s. There has been a fundamental shift in animal production over the last century. It is evident that this shift, which favours intensive animal rearing, has led to an increase in energy content of primary foods such as chicken and beef.
This may have contributed to obesity in the developed countries.
15. Immune Function
(15-1) MONONUCLEAR CELL FATTY ACID COMPOSITION AND IMMUNE STATUS OF TERM
AND PRETERM NEONATES
T. Moodley1, M.A. Crawford1, K. Gebremeskel1 and O. Djahanbakhch2,1IBCHN, London Metropolitan University, London, UK
2Barts and the London School of Medicine at Newham General Hospital, London, UK
Preterm neonates are more susceptible to infection than term neonates. The optimal functioning of the immune cell membrane receptors is important for antigen recognition. Receptor function is dependent on membrane organisation
and fluidity, which is governed by the fatty acid composition of the membrane. The aim was to establish a preliminary profile of the membrane fatty acids of cord blood mononuclear (MN) cells in
term (<37weeks; n=9) and preterm (<37 weeks; n=10) neonates. The term (n=25) and preterm (n=25) whole blood concentrations of key lymphocyte subsets of T-helper (CD4), T-cytotoxic (CD8) and B-cells (CD19), as well as memory
(CD45RO), naïve (CD45RA) and IL-2-bearing (CD25) cells, were also measured. Compared to term neonates, preterm neonates showed lower levels of AA, DHA, DHGLA, LA and gamma-LNA in the
ethanolamine phosphoglycerides (p<0.001) and lower levels of AA, DHA and DHGLA in the choline phosphoglycerides (p<0.001). Subset analysis showed that preterms had significantly lower absolute counts of CD4 T-cells and CD4 and
CD8 naïve cells. Lower levels of LCPUFAs, which are likely to affect membrane function, and smaller numbers of immune cells, may contribute to susceptibility to infection. Fetal immune cell status may be improved by appropriate
dietary supplementation in the antenatal period.
(15-2) THE EFFECT OF ARACHIDONIC AND DOCOSAHEXAENOIC ACIDS ON THE
PROLIFERATION OF CORD BLOOD MONONUCLEAR CELLS
T. Moodley1, C. Vella1, O. Djahanbakhch2, K. Ghebremeskel1 , and M. A. Crawford1,1IBCHN, London Metropolitan University, London, UK
2Barts and the London School of Medicine at Newham General Hospital, London, UK
Arachidonic (AA) and docosahexaenoic (DHA) acids are vital structural and functional components of vascular, neural and immune cells. Changes in the cell membrane fatty acid composition have a profound effect on |
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