Ritanserin, a serotonin-S2 receptor antagonist, does not prevent 5-hydroxytryptophan-induced beta-EP, beta-LPH and cortisol secretion.
Ritanserin, a new serotonin antagonist selective upon S2 receptor subclass is available. Thus, in order to better define the positive control of serotoninergic pathway on proopiomelanocortin (POMC)-related peptide release, a group of 7 healthy male volunteers has been submitted to a 5-hydroxytryptophane (5-OH-TP) test (200 mg p.o.) before and after 4 days Ritanserin pretreatment. Plasma beta-endorphin (beta-EP), beta-lipotropin (beta-LPH) and cortisol levels were measured hourly for 4 h after each 5-OH-TP loading. Hormonal levels were measured by specific RIAs on extracted (cortisol) and chromatographed (beta-EP and beta-LPH) plasma samples. Basal plasma concentrations of the three hormones were unchanged by Ritanserin pretreatment. Similarly, the integrated areas of beta-LPH, beta-EP and cortisol release in response to 5-OH-TP remained unaffected by the receptor blockade. These data confirm that serotonin-acting drugs are able to stimulate POMC-related peptide release and indicate that such interaction is not mediated through S2 receptor subclass.
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000293:Adolescent; D004723:Endorphins / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D010880:Piperidines / Q000494:pharmacology*; D016713:Ritanserin; D012636:Secretory Rate / Q000187:drug effects; D012701:Serotonin / Q000502:physiology*; D013997:Time Factors; D001615:beta-Endorphin; D008083:beta-Lipotropin / Q000378:metabolism*
D004723:Endorphins; D010880:Piperidines; D016713:Ritanserin; D012701:Serotonin; D001615:beta-Endorphin; D008083:beta-Lipotropin; D006916:5-Hydroxytryptophan; D006854:Hydrocortisone