[Effect of streptozotocin at the insulin pre-receptor, receptor and post-receptor level in adipocytes of rats].

The relationship among plasma insulin disappearance, insulin binding to specific receptors in fat cells and antilipolytic insulin activity in streptozotocin-diabetic rats has been studied. Male Wistar rats were injected streptozotocin (65 mg/kg body weight) or saline by cardiac puncture. Decreased insulin levels and increased insulin degradation together with an increase in insulin binding were found in diabetic rats. The increase in insulin binding was related to an increase in the number of insulin receptors rather than to a change in receptor affinity. These findings at the pre-receptor and receptor levels could be correlated with an increase in antilipolytic insulin activity. However our results suggest that the mechanism for insulin action occurred through a potentiation of the norepinephrine lipolytic activity.