The potentiating influence of imipramine on ganglionic effects of catecholamines

Abstract

The actions of imipramine on the inhibitory effects of the catecholamines norepinephrine, epinephrine and dopamine on transmission in the superior cervical ganglion of the cat were studied, in order to observe its influence on adrenergic sites at the synaptic level. Lower doses of imipramine potentiated only the inhibitory effects of norepinephrine, although with higher doses the potentiation of epinephrine action was also noted. The effects of dopamine were not changed significantly. Imipramine was found to depress ganglionic transmission, and it is suggested that it increases the amount of free norepinephrine acting on neurones involved in cholinergic transmission.