Alteration of adipocyte metabolism in ω3 fatty acid-depleted rats

Presently an insufficient supply of long-chain polyunsaturated omega 3 fatty acid is prevalent in Western populations leading to potential metabolic consequences. Based on this fact, this study deals mainly with various aspects of lipid metabolism in second generation female omega 3-depleted rats. The parametrial fat and body weights were higher in omega 3-depleted than control animals. This coincided with liver steatosis but did not alter heart triglyceride/phospholipid ratio. The net uptake of [U-C-14] palmitate by adipocytes was also higher in omega 3-depleted rats than in control animals. The uptake Of D-[ U-C-14]glucose or [1,2-C-14]acetate by adipocytes was lower, however in omega 3-depleted than control animals and was unaffected by insulin in the former as distinct from latter animals. Despite comparable basal lipolysis, the increase in glycerol output from adipocytes provoked by theophylline was higher in omega 3-depleted than control rats. The fatty acid pattern of lipids in adipose tissue was characterized in the omega 3-depleted rats by a much lower omega 3 content, higher apparent Delta(9)-saturase and elongase activities, lower efficiency for the conversion of C18:2 omega 6 to C20:4 omega 6 and higher efficiency for the conversion of C18:3 omega 3 to C20:5 omega 3. These features were compared to those prevailing in liver and plasma lipids. The present study thus extends knowledge on the alteration of lipid metabolism resulting from a deficiency in long-chain polyunsaturated omega 3 fatty acids.