Abstrait

Alteration Of Desaturase- And Elongase-Catalyzed Steady-State Equilibrium Between Selected Fatty Acids In The Liver Phospholipids And Triglycerides Of 3-Depleted Rats:Comparison With Plasma Lipids

Willy J.Malaisse, Yvon A.Carpentier, Laurence Portois, Jean-Michel Chardigny

Several anomalies of lipid metabolism were recently documented in longchain polyunsaturated 3 fatty acid-depleted rats (second generation). The present study draws attention to perturbations of desaturase- and elongase-catalyzed steady-state equilibrium between selected fatty acids in liver phospholipids and triglycerides. When compared to normal rats, the most salient findings in the 3-depleted rats consisted in a decreased activity of 9-desaturase as judged from both the C16:0/C16:17 and C18:0/C18:19 ratios in liver phospholipids and an increased activity of 6-desaturase as judged from the C18:26/C18:36 ratio in both liver phospholipids and triglycerides. The sole obvious changes in elongasecatalyzed equilibrium values consisted in lower values for the C20:46/ C22:46 and(C16:0+C16:17)/(C18:0+C18:19) ratios in the liver phospholipids of 3-depleted rats versus control animals. In all cases, there were highly significant correlations between the concerned ratios as measured in liver triglycerides versus plasma triglycerides or unesterified fatty acids and liver versus plasma phospholipids. It is proposed, therefore, that the measurements of such ratios in blood cell and/or plasma lipids could conceivably be informative in human subjects affected by an insufficient dietary supply of long-chain polyunsaturated 3 fatty acids.