Indolealkylamines and prolactin secretion. A structure-activity study in the central nervous system of the rat

The present study was performed to examine the central effects of the indolealkylamine hallucinogens, 5-methoxy-N,N-dimethyltryptamine (MDMT), bufotenin and N, N-dimethyltryptamine (DMT), infused intracerebroventricularly (i.c.v.) into the lateral ventricle. They were found to have a stimulatory effect upon the secretion of prolactin. Their order of potency was compared. From a structure-activity point of view, MDMT is the most potent, followed by bufotenin, and then by DMT. Bufotenin, which does not readily cross the blood-brain barrier, caused a prolonged effect on the elevation of prolactin, with a suggestion of a biphasic effect at the maximum dose (0.02 M). N,N-dimethyltryptamine showed a clear dose-response relationship in the stimulation of the release of prolactin. The present results confirm those of previous investigators, who have demonstrated that these drugs cause the release of prolactin, with a possible biphasic effect. The present results suggest that, the response which was obtained was centrally mediated, and probably did not involve stimulation of peripheral receptors and the time course of action of indoles is different when infused centrally, compared to their time course when infused peripherally.