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-[1-3H]-deoxyglucose. The main effect of these hormones was to reduce insulin-induced glucose utilization in skeletal muscles and particularly in the oxidative one.

Effects of hyperinsulinemia on local cerebral insulin binding and glucose utilization in normoglycemic awake rats.

The present study was carried out to characterize the effects of insulin, using the euglycemic hyperinsulinemic clamp, on insulin binding and glucose utilization in specific areas of rat brain, by autoradiographic methods. Binding of [125I]Insulin was significantly higher in the hippocampus CA1, the ventromedial and lateral hypothalamus nuclei of the hyperinsulinemic rats than in control rats. Glucose utilization was slightly but not significantly decreased in the hippocampus CA1, the ventromedial and lateral hypothalamus of hyperinsulinemic rats.