Effects of chronic administration of amitriptyline or mianserin on rat cardiac and central adrenoceptors.

Rats were administered either amitriptyline (20 mg kg-1, i.p.) or mianserin (10 mg kg-1, i.p.) for 21 consecutive days and the alpha- and beta-adrenoceptor characteristics of cardiac ventricles, cerebral cortex and hippocampus examined by ligand-binding procedure. Chronic administration of amitriptyline significantly reduced the maximum density of beta-receptors in the cerebral cortex without significantly altering cardiac alpha- or beta-receptors; mianserin treatment had no significant effect on any of the receptors studied.