The beta-adrenoceptor controlling renin release.

The beta-adrenoceptor antagonists, atenolol, metoprolol and propranolol, administered intravenously to anaesthetized rats in doses producing equal beta1-adrenoceptor blocking effects, caused comparable suppression of plasma renin activity (PRA) despite the fact that, at these doses, atenolol and metoprolol exhibited no beta2-adrenoceptor blocking properties. Practolol, an agent specific for beta1-adrenoceptors but possessing intrinsic sympathomimetic activity, caused less marked suppression of PRA. When doses of atenolol, metoprolol, propranolol and butoxamine were selected to achieve equal beta2-blocking effects, PRA was again significantly suppressed by atenolol and metoprolol but not by propranolol or butoxamine. These results do not support the concept that adrenergic release of renin is mediated by beta2-adrenoceptors, but are compatible with the involvement of a beta1-adrenoceptor-mediated mechanism.