Age-related and sex-related alterations in beta-adrenergic receptors in different regions of rat brain.

The binding of (-)[3H]dihydroalprenolol, an antagonist of norepinephrine, to beta-adrenergic receptors in different regions of the brain of male and female rats of various ages was measured. The binding to the synaptosomal fraction of corpus striatum, hypothalamus, cerebral cortex, cerebellum and the brainstems shows a significant decrease in the binding in old rats of both sexes. Only in the female corpus striatal region, the binding in the adult and the old is the same. In the case of females, the highest binding is seen in the young. In the male, an increase in binding occurs up to adulthood, after which it declines, suggesting a definite sex-related difference in the beta-adrenergic receptor.