Effect of 5-hydroxytryptamine on gastric motility and efferent gastric vagus nerve activity in rats.
Intravenous administration of 5-hydroxytryptamine (5-HT) produced a depressor effect on pyloric pressure and an increase in the duration of this depressor effect on gastric pressure dose-dependently in anesthetized rats. Pretreatment with a selective 5-HT3-receptor antagonist, ICS 205-930 (10 micrograms/kg), inhibited these effects. Intravenous administration of 5-HT produced a dose-dependent increase in efferent gastric vagus nerve activity (GVNA). A selective 5-HT3-receptor agonist, 2-methyl-5-HT, also produced a dose-dependent increase in GVNA. Pretreatment with a selective 5-HT3-receptor antagonist, ICS 205-930 (10 micrograms/kg), caused a shift to the right in both the 5-HT and 2-methyl-5-HT dose-response curves. These findings suggest that exogenous 5-HT activates efferent vagus gastric nerve activity and may trigger or mediate the gastric motility via 5-HT3-receptors.
Yoshioka
M
M
First Department of Pharmacology, Hokkaido University School of Medicine, Sapporo, Japan.
Ikeda
T
T
Togashi
H
H
Saito
Y
Y
Saito
H
H
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004525:Efferent Pathways; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007211:Indoles / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D011292:Premedication; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D000077526:Tropisetron; D014630:Vagus Nerve / Q000187:drug effects*
D007211:Indoles; D012702:Serotonin Antagonists; D012701:Serotonin; D000077526:Tropisetron