The effects of intravenous administration of cholecystokinin on feeding behaviour and release of pituitary hormones in pigs are not mediated by serotonergic (5-HT3) receptors

Abstract

Two experiments were carried out using the serotonergic (5-HT3) antagonist ondansetron (GR 38032F) to investigate whether the actions of peripherally-administered cholecystokinin octapeptide (CCK) in the prepubertal pig might involve 5-HT3 receptors. In Experiment 1, it was shown that ondansetron (10 or 30 mg, i.v.) did not affect the initial feeding response and did not modify the behavioural inhibition induced by a subsequent injection of CCK (1.3 μg/kg, i.v.). In Experiment 2, it was demonstrated that the nauseogenic action of CCK, indicated by its stimulatory effect on release of vasopressin and Cortisol, was not markedly altered by ondansetron (30 mg, i.v.). These results suggest that 5-HT3 receptors play a negligible part in mediating the behavioural and endocrine responses induced by bolus intravenous injections of CCK in this species. © 1992.