Induction of emesis in Suncus murinus by pyrogallol, a generator of free radicals.
1. We investigated whether or not pyrogallol, a generator of free radicals, is emetogenic in Suncus murinus, the house musk shrew. Pyrogallol (i.p.) caused dose-dependent emesis in suncus with an ED50 value of 77.3 mg kg-1. At a dose of 128 mg kg-1, all suncus vomited with mean latency of 18.8 +/- 5.2 min and the number of vomiting episodes was 8.6 +/- 2.9. 2. The prophylactic effects of N-(2-mercaptopropionyl)-glycine (MPG), an antioxidant, and tropisetron, a 5-hydroxytryptamine3 (5-HT3) receptor antagonist, were studied. Pyrogallol (128 mg kg-1, i.p.)-induced emesis was prevented by treatment with MPG (i.p.) or tropisetron (s.c.) with ID50 values of 149 mg kg-1 and 117 micrograms kg-1, respectively. 3. Pyrogallol-induced emesis was completely prevented by surgical abdominal vagotomy. 4. The present results indicate that pyrogallol-induced emesis is characteristically very similar to that caused by cisplatin and support the idea that generation of free radicals causes the release of peripheral 5-HT, which stimulates vagal afferent sensory nerves to cause emesis.
Torii
Y
Y
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Saito
H
H
Matsuki
N
N
D000818:Animals; D000932:Antiemetics / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005609:Free Radicals / Q000378:metabolism / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D011748:Pyrogallol / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D012701:Serotonin / Q000494:pharmacology; D012788:Shrews / Q000502:physiology*; D014628:Vagotomy; D014839:Vomiting / Q000139:chemically induced*
D000932:Antiemetics; D005609:Free Radicals; D011748:Pyrogallol; D012701:Serotonin