Effects of isoproterenol on the development of beta-adrenergic receptors in brain cell aggregates

The development of binding sites for the beta-adrenergic receptor antagonist [125I]iodohydroxybenzylpindolol in reaggregate cultures of fetal rat brain has been investigated. beta-Adrenergic receptor density increased rapidly between 6 and 22 days in culture at which time maximal density was attained. When cultures were grown in the presence of the beta-adrenergic receptor agonist isoproterenol, the development of receptors was markedly inhibited. Cultures were also grown for 15 days in the presence of isoproterenol and then for 7-14 days in the absence of isoproterenol. Following the removal of the agonist, binding sites developed, but to only approximately 50% of the density seen in control cultures.