Ganglion-blocking properties of atropine-like drugs.

The ganglion-blocking properties of atropine, atropine methyl nitrate, oxyphenonium, poldine, methantheline and propantheline have been examined and compared with those of hexamethonium, mecamylamine, pentolinium and tetraethylammonium. The ganglion-blocking activity was assessed by stimulating the preganglionic nerve to the superior cervical ganglion and recording directly the percentage depression in the postganglionic action potentials. In this way any ambiguity due to the peripheral actions of the drugs was removed. As a group the atropine-like compounds are not markedly less potent than the ganglion-blocking agents, but their action is relatively transient. This work suggests that the ganglion-blocking action of atropine-like substances plays no part in their therapeutic effects.