Comparison of the antimuscarinic activity of mianserin and amitriptyline in the cat superior cervical ganglion.

The antimuscarinic activity of mianserin and amitriptyline was investigated in the cat superior cervical ganglion using McN-A-343 as a muscarinic agonist. Mianserin was found to have a similar order of potency to amitriptyline in this preparation, in contrast to the marked difference in their antimuscarinic activities on non-neuronal muscarinic receptors. These findings suggest that the action of mianserin on neuronal muscarinic receptors is more important than that predicted from studies on non-neuronal receptors and may be related to its anti-depressant activity.