Plasma free fatty acid appearance in plasma triglycerides

Abstract

The rate of plasma free fatty acid appearance in the plasma triglycerides was determined in the dog. 14C palmitic acid was infused and the rate of appearance of the label in the triglyceride, which was separated by TLC, was calculated. Normal resting dogs were compared to those receiving 10 per cent glucose or norepinephrine along with the radioactive fatty acid. Pancreatectomized dogs before and after insulin administration were also investigated. A correlation was found between the plasma FFA turnover and the rate of appearance. When the FFA turnover was high (norepinephrine, pancreatectomy), the rate of appearance was high (3–4 μM min.), and when the FFA turnover rate was low (10 per cent glucose infusion or after insulin), the rate of appearance was low (.366 μM min.). The rate of appearance of free palmitic acid in the palmitic acid of the triglycerides was calculated. The rate of palmitic appearance was also dependent on the palmitic turnover rate. The rate of appearance was approximately 1 per cent of the FFA turnover rate when calculated from the total or the palmitic acid data. It was suggested that the major site of triglyceride production was nonhepatic.