Metabolism of palmitate and linoleate in intact dogs

Abstract

Palmitate-9, 10-H³ and linoleate-1-C¹⁴ were infused simultaneously into intact dogs as albumin-bound free fatty acids or as esterified fatty acids in chylomicrons. Linoleate bound to albumin was removed more rapidly from the plasma and was incorporated more extensively into triglycerides of very low density lipoproteins of plasma than palmitate. Both linoleate and palmitate were incorporated more slowly into triglyceride fatty acids of low density and high density lipoproteins than into those of very low density lipoproteins. When chylomicrons obtained separately from dogs fed palmitate-9, 10-H³ with milk fat and linoleate-1-C¹⁴ with corn oil were mixed and infused into recipients, the rates of removal from the blood of both triglycerides and phospholipids of the two populations of chylomicrons differed, but this did not seem to depend on their chemical composition. Linoleate derived from chylomicron triglycerides disappeared from hepatic triglycerides and phospholipids more rapidly than palmitate and was incorporated more extensively into plasma lipids. Palmitate and linoleate were incorporated in equivalent amounts into circulating free fatty acids, but more linoleate was found in lipids of adipose tissue.