EFFECTS OF COUNTERREGULATORY HORMONES ON INSULIN-INDUCED GLUCOSE-UTILIZATION BY INDIVIDUAL TISSUES IN RATS

The effect of counterregulatory hormones (epinephrine, norepinephrine and glucocorticoids) on insulin-induced glucose utilization in individual tissues of normal rats was investigated in vivo. This was done in normoglycaemic conditions, using the euglycaemic hyperinsulinaemic clamp combined with an injection of 2-[1-H-3]-deoxyglucose. The main effect of these hormones was to reduce insulin-induced glucose utilization in skeletal muscles and particularly in the oxidative one. No changes were observed in heart diaphragm and adipose tissues. These results emphazise the role of counterregulatory hormones on glucose utilization and demonstrate that muscles are their major site of action. They support the notion that the increase in plasma concentrations of these hormones could play a role in states of insulin resistance like obesity and diabetes.