Repeated administration of 5-methoxy-N,N-dimethyltryptamine to male rats potentiates stimulation of prolactin secretion by serotonin agonists.

Repeated administration of 5-methoxy-N,N-dimethyltryptamine (5MeODMT, 5 mg/kg, a serotonin agonist, every 3 h for a total of 4 injections) potentiated its prolactin (PRL)-releasing effect and that of two other serotonin agonists, quipazine and N,N-dimethyltryptamine. This pretreatment schedule had no effect on PRL response to anti-dopaminergic drugs. The onset of enhanced PRL response to serotonin agonists was gradual and appears to be due to sensitization of the serotonergic mechanism involved in the regulation of PRL secretion. The possible mechanisms underlying this phenomenon are discussed.