Do Ganglion-Blocking Agents and Reserpine Affect Central Vasomotor Activity?

Abstract

In a majority of experiments on both dogs and cats, hypotensive doses of tetraethylam-monium chloride or mecamylamine caused no change or moderate increase in efferent electric activity in the largely preganglionic thoracic portion of the splanchnic nerve, and caused complete and prolonged elimination of efferent activity in the postganglionic inferior cardiac and renal nerves. Both drugs failed to suppress changes in splanchnic nerve activity that were elicited refiexly. These results imply strongly that both ganglion-blocking drugs, in dosage used intravenously to induce hypotension, act mainly through their peripheral effects rather than through one on central vasomotor synapses. In both dogs and cats, reserpine caused slowly progressive and marked diminution in efferent splanchnic nerve activity, which supports the hypothesis that the central action of this agent contributes to its hypotensive effect.