Postnatal alterations in beta-adrenergic receptor binding in rat brain regions after continuous prenatal exposure to propranolol via maternal infusion.

Early exposure of developing postsynaptic receptors to the appropriate neurotransmitter is thought to be important for establishing the pattern of receptor development and function. We have examined the role of fetal catecholamines in central nervous system beta-adrenergic receptor maturation by administering the beta-adrenergic antagonist, propranolol, throughout gestation via continuous maternal infusion in rats. After birth, we examined beta-receptor binding of [125I]pindolol in three brain regions. In the cerebral cortex, receptor binding was relatively normal in the propranolol group during the immediate postpartum period, but eventually became elevated in young adulthood. Binding characteristics were not significantly affected in midbrain + brainstem or cerebellum. These data support a role for fetal catecholamines in the programming of subsequent receptor development, but in a fashion selective for specific brain regions.