Accelerated Clearance of Plasma Triglycerides and Free Fatty Acids in ω3-depleted Rats

Abstract

The present study aims mainly at exploring the effects of a severe depletion in polyunsaturated long-chain ω3 fatty acids upon the fate of circulating lipids. The plasma concentration and fatty acid pattern of triglycerides, diglycerides, free fatty acids, and phospholipids were measured in ω3-depleted and control rats injected intravenously one hour before sacrifice with either saline, a control medium-chain triglyceride:olive oil emulsion or a medium-chain triglyceride:fish oil emulsion recently found to rapidly increase the phospholipid content of C20:5ω3 and C22:6ω3 in different cell types. The estimated fractional removal rate of the injected triglycerides and the clearance of free fatty acids from circulation were both higher in ω3-depleted rats than in control animals. The injection of the lipid emulsions apparently inhibited intracellular lipolysis, this being least pronounced in ω3-depleted rats. The increased clearance of circulating triglycerides and unesterified fatty acids in ω3-depleted rats may favor the cellular accumulation of lipids. In turn, such an accumulation and the lesser regulatory inhibition of tissular lipolysis may match the increased clearance of circulating unesterified fatty acids and, hence, account for the lack of any significant difference in plasma unesterified fatty acid concentration between these and control animals.

Key words

plasma triglyceride - fatty acid clearance - long-chain polyunsaturated ω3 fatty acid-depleted rats

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