Differential decrease of the central beta-adrenergic receptor in the rat after subchronic infusion of desipramine and clenbuterol.

The effect of subchronic infusion of desipramine, a norepinephrine uptake inhibitor, and clenbuterol, a beta-adrenergic agonist, on the central beta receptor of the rat was determined using in vitro [(3)H]dihydroalprenolol binding. Desipramine produced significant decreases of the receptor in neocortex and hippocampal formation, and clenbuterol effected such decreases in corpus striatum and cerebellum. Both drugs caused a marked decrease in the activity of isoproterenol-sensitive adenylate cyclase in neocortex. The alpha(2) receptor of neocortex and cerebellum was unchanged by either drug as assessed by in vitro[ (3)H ]p- aminoclonidine binding. The results are discussed in terms of the different mechanisms of action of desipramine and clenbuterol, and the efficacy of these two drugs in the treatment of depression.