“Insulin-like” Action of Oxytocin: Evidence for Separate Oxytocin-Sensitive and Insulin-Sensitive Systems in Fat Cells

Abstract

The effect of insulin and oxytocin on glucose oxidation and lipid synthesis has been studied in isolated fat cells. Insulin and oxytocin both stimulate glucose utilization in fat cells; however, these hormones act through different mechanisms as shown by the following findings: 1) Doses of both hormones, which individually give maximal responses, when combined produce additive effects; 2) N-carbamyl-O-methyloxytocin, a specific oxytocin antagonist, markedly inhibited the lipogenic response of fat cells to oxytocin without affecting * the insulin response; 3) omission of calcium from the external medium completely abolished the metabolic effects of oxytocin, but did not influence the stimulatory effect of insulin on glucose utilization in fat cells. (Endocrinology85: 1092, 1969)