Métabolisme des acides gras oméga-3 : différences entre hommes et femmes

Abstract

The polyunsaturated fatty acids made of 18 atoms of carbon from the omega-6 and omega-3 series are necessarily supplied by food. These essential precursors are converted into long-chain derivatives which are major functional components of membrane cells, the arachidonic and docosahexaenoic acids (DHA), respectively. The conversion pathway involves successive reactions of desaturations and elongations, taking place mainly in the liver, which genes are regulated through the action of cognate transcription factors. We review litterature data on the influence of sexual dimorphism on the regulation pathway of omega-3 metabolism. It is shown that a-linolenic acid, the essential precursor of omega-3 series, is mainly oxidised to acetyl-coA in mitochondries while only a minor fraction is converted to DHA through endoplasmic reticulum and peroxisomal processing. The metabolic parts intended for oxidation and conversion are, respectively, lower and higher in women than in men. In standard nutritional conditions, the DHA content in blood lipids is generally higher in women, especially in those having estrogenic treatments. As a whole, the published data support the hypothesis that the steroid hormonal status impacts on the signaling pathway that regulates the gene expression of lipid metabolism.