TIMING OF NEUROENDOCRINE RESPONSES AND EFFECT OF M-CPP AND FENFLURAMINE PLASMA-LEVELS IN OCD

The present study assesses the timing of and relationship between neur oendocrine response and metabolite blood levels following the partial serotonin (5-HT) agonist m-CPP and the 5-HT releaser/reuptake blocker fenfluramine. Cortisol levels peaked significantly earlier than did pr olactin, m-CPP, fenfluramine, or norfenfluramine blood levels by time- to-peak analysis. This earlier cortisol response to both 5-HT agents r aises the possibility that peripheral mechanisms may play a role in co rtisol release. Since peak m-CPP level correlated even more closely to peak prolactin rise than did peak fenfluramine, this suggests that pr olactin response to oral m-CPP challenge is useful in assessing 5-HT f unction.