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. These data suggest that insulin, via its specific receptors, may exert its central actions by affecting glucose utilization.