[Effect of dietary alpha-linolenic acid on the conversion of linoleic and gamma-linolenic acids (1-14C) into arachidonates in rats in vivo].
The effects of alpha-linolenic acid (9-12-15 octadecadienoic) upon the conversion in vivo of [1-14C] linoleic acid and of [1-14C] gamma-linolenic acid into arachidonate have been studied in adult rats. The two tracers have been administered by stomach tubing and the amounts of [14C]-radioactivity incorporated into arachidonate in the liver, kidneys and whole rat have been measured 48 h later. Three experiments have been carried out on rats fed on alpha-linolenic acid containing diets prior to the radioactive tubing. In these diets, alpha-linolenic acid was brought either as ethyl ester or in the form of Primor oil (erucic acid free rapeseed oil). In all of them, the ratio alpha-linolenic acid: linoleic acid did not exceed 0.45. Control animals were fed, in the same conditions, ethyl oleate or peanut oil respectively. Comparing the alpha-linolenic acid fed-rats to the control animals, we were able to observe the following results: (1) The exogenous supplies of alpha-linolenic acid used in the diets have not brought about any significant alteration in the amounts (weights) of arachidonic acid present in the liver, kidneys and whole animal. (2) Using [1-14C] linoleic acid as a precursor, the amounts of [14C]-radioactivity incorporated into arachidonate in the same organs as well as in the whole rat have been significantly lowered by dietary alpha-linolenate. (3) alpha-Linolenate, on the contrary, had no significant effect upon the amounts of radioactivity incorporated into hepatic, renal and whole body arachidonate following the administration of [1-14C] gamma-linolenic acid. These results lead to the conclusion that alpha-linolenic acid, when present in the diet of rats at a limited, phyisological level, partly inhibits the desaturation of linoleic acid in vivo but does not affect the subsequent reactions in the biosynthesis of arachidonic acid.
D000818:Animals; D001095:Arachidonic Acids / Q000096:biosynthesis*; D004041:Dietary Fats / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008041:Linoleic Acids / Q000378:metabolism*; D008042:Linolenic Acids / Q000378:metabolism* / Q000494:pharmacology; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats
D001095:Arachidonic Acids; D004041:Dietary Fats; D005227:Fatty Acids; D008041:Linoleic Acids; D008042:Linolenic Acids
Influence de L'acide alpha-linolénique alimentaire sur la conversion des acides linoléique et gamma-linolénique [1-14C] en arachidonate chez le rat in vivo.