Effect of Insulin on Fatty Acid Synthesisin Vivoandin Vitroin Pancreatectomized Rats

Publisher Website
Google Scholar
Abstract
Fatty acid synthesis in vivo was examined in liver, adipose tissue and carcass of "totally" pancreatectomized and normal rats by measuring the incorporation of tritium from 3H2O into fatty acids. Synthesis was greatly depressed in both fasted pancreatectomized and fasted normal rats. Tube-feeding stimulated fatty acid synthesis in liver, adipose tissue and carcass of normal but not in untreated diabetic rats. Insulin, injected subcutaneously, stimulated within 30 min fatty acid synthesis in the liver, adipose tissue and carcass of pancreatectomized rats deprived of insulin for 17 hr. The effect of insulin (12 U) on fatty acid synthesis lasted for about 2 hr. in adipose tissue and 4 hr. in liver and carcass. Withholding insulin and food for 48 hr. decreased but did not abolish the effect of injected insulin on fatty acid synthesis in pancreatectomized rats. In vitro studies of fatty acid synthesis in the liver (with glucose-U-C14, fructose-U-C14 and acetate-1-C14) and in adipose tissue (with glucose-U-C14) confirmed the findings made in vivo. The rapid effect of insulin on hepatic fatty acid synthesis is interpreted as evidence of a direct action of insulin on the liver.