Intraventricular administration of reserpine and its metabolites to conscious cats.

Intraventricular injection of reserpine in conscious cats produced relaxation of the nictitating membrane, miosis with narrowing of the palpebral fissure to a slit, avoidance of light, diarrhoea, anorexia, and tranquillization. Equivalent doses of trimethoxybenzoic acid, reserpic acid or methylreserpate separately or in combination did not produce such effects, indicating that these reserpine metabolites were not involved in these reserpine actions. 5-Hydroxytryptamine alone or in combination with subthreshold doses of reserpine also did not duplicate the effects observed after effective doses of reserpine. The possible central sites of reserpine action are discussed.