The influence of imipramine on dopamine-induced ganglionic inhibition and neurogenic vasodilatation in the dog.

Imipramine potentiates the dopamine-induced inhibition in the paravertebral lumbar ganglia of the dog. Potentiation by imipramine of the dopamine-induced neurogenic vasodilatation in the isolated perfused gracilis muscle, is seen in cross-circulation preparations only, where imipramine is injected into the perfusion circuit of an isolated perfused gracilis muscle, it antagonizes the dopamine-induced neurogenic vasodilatation. When imipramine is injected intravenously into a dog with an autoperfused gracilis muscle, the peripheral antagonism masks the potentiating effect at the ganglionic level, and the dopamine-induced neurogenic vasodilatation is abolished.