5-Hydroxytryptamine is emetogenic in the house musk shrew, Suncus murinus.
The emetic effects of 5-hydroxytryptamine (5-HT) and 5-HT3 receptor agonists were investigated in the house musk shrew, Suncus murinus. 5-Hydroxytryptamine (5-HT; i.p., i.v., s.c.) and 2-methyl-5-HT (2-Me-5-HT; i.p.) but not 5-hydroxyindoleacetic acid (i.p.) or 5-methoxytryptamine (i.p.) induced emesis with very short latency. Tropisetron (ICS 205-930, a 5-HT3 receptor antagonist, s.c.) blocked the emesis induced by 5-HT (10 mg/kg, i.p.) and 2-Me-5-HT (5 mg/kg, i.p.) with respective ID50 values of 7.8 and 70.9 micrograms/kg. Pindolol (5-HT1 receptor antagonist) and ketanserin (5-HT2 receptor antagonist) were about 100 times less potent than tropisetron. The emesis induced by 5-HT was prevented by surgical vagotomy but not by pretreatment with a combination of atropine (0.1 mg/kg, s.c.) and hexamethonium (10 mg/kg, s.c.). These results clearly indicate that 5-HT is emetogenic probably through a stimulation of peripheral 5-HT3 receptors.
Torii
Y
Y
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Saito
H
H
Matsuki
N
N
D008735:5-Methoxytryptamine / Q000633:toxicity; D000818:Animals; D005260:Female; D006897:Hydroxyindoleacetic Acid / Q000633:toxicity; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008297:Male; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000008:administration & dosage / Q000633:toxicity*; D012702:Serotonin Antagonists / Q000494:pharmacology; D012788:Shrews; D014628:Vagotomy; D014839:Vomiting / Q000139:chemically induced*
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012701:Serotonin; D008735:5-Methoxytryptamine; D006897:Hydroxyindoleacetic Acid