0000000000040218
AUTHOR
Virginie Mimouni
Effect of sodium loading (3% NaCl) on arachidonic acid biosynthesis in rat liver microsomes
Sodium loading increases arachidonic acid (AA) metabolism by way of the prostaglandins(PGs) from series 2. Its effect on AA biosynthesis remains unknown. The purpose of the present study was to investigate the influence of sodium loading on the fatty acid composition of liver and liver microsomes, and the liver microsomal delta-6 and delta-5 desaturations of linoleic acid (LA) into AA. We found a decrease of LA and dihomo-gamma-linolenic acid (DGLA) levels in liver total lipids of Wistar rats receiving hypernatriuretic drinking water (NaCl 3%) for 60 days. At the same time AA increased. DGLA decreased and AA increased in liver microsomal total lipids. 1(14) C-LA delta-6 desaturase and 2(14)…
Altered desaturase activities and fatty acid composition in liver microsomes of spontaneously diabetic Wistar BB rat.
We examined the activities of delta 9, delta 6 and delta 5 desaturases and fatty acid composition of liver microsomes in the insulin-dependent spontaneously diabetic adult female Wistar Bio-Breeding (BB) rat. The diabetic BB rats were subcutaneously injected with different doses of protamine zinc insulin in order to be killed in hyper-, normo- or hypo-glycemic states. Desaturase activities, which are partially inhibited by spontaneous diabetes during the normo- and hyper-glycemic periods, were similarly affected by the various insulin treatment; delta 9 desaturase activity being more depressed than the desaturase activities of either delta 6 of delta 5. Insulin treatment with 10 I.U./kg bod…
Adrenic acid Δ4 desaturation and fatty acid composition in liver microsomes of spontaneously diabetic Wistar BB rats
We examined the delta 4 (n-6) desaturation and the fatty acid composition of liver microsomes in the insulin-dependent spontaneously diabetic Wistar Bio-Breeding (BB) rat. The desaturation of adrenic acid to n-6 docosapentaenoic acid was decreased in the normo- and hyperglycemic diabetic rats. Insulin treatment with 1.0 IU. 100 g body weight-1 twice a day for 2 days restored the reduced activity during the hypoglycemic period. The pattern of responses was similar to that of linoleic acid delta 6 and dihomo-gamma-linolenic acid delta 5 desaturases, with a non-parallel relationship between the desaturation system and the glycemia. The microsomal fatty acid composition of BB rat liver reflecte…
Elongation and desaturation of arachidonic and eicosapentaenoic acids in rat liver. Effect of clofibrate feeding
The fatty acid elongation-desaturation ability of 5,8,11,14-eicosatetraenoic (20:4(n-6)) and 5,8,11,14,17-eicosapentaenoic (20:5(n-3)) acids was determined in both liver microsomal and light mitochondrial (rich in peroxisomes) fractions of untreated and clofibrate treated rats. The elongation and the subsequent desaturation steps were performed in the corresponding favorable media. 20:5(n-3) elongation was about 2-times more extensive than that of 20:4(n-6). Clofibrate feeding for 10 days resulted in a marked decrease in the elongation rate with the two substrates, while the delta 4 desaturation rate was increased. There were small differences in the elongation rate between the microsomal a…
Relationship between rat liver microsomal Δ6 and Δ5 desaturase activities and fatty acid composition: comparative effects of coconut and salmon oils during protein restriction
International audience; The aim of this work was to compare the effects of coconut and salmon oils on rat liver microsomal Δ6 and Δ5 desaturations, during protein restriction. A higher Δ6 desaturase activity was noted in rats fed the low-protein coconut oil diet, in comparison with that occurring in rats fed either a low-protein or normal-protein salmon oil diet. No variation was observed in Δ5 desaturase activity or in 20:4n-6/ 18:2n-6 ratio. The fatty acid composition of liver microsomal phospholipids provided evidence of higher levels of 20:5n-3 and 22:6n-3 in the normal-protein salmon oil group, when compared with the low-protein salmon oil group. No influence of experimental diets on t…