title: Effect of the selective 5-HT3 receptor antagonists ICS 205-930 and MDL 72222 on 5-HTP-induced head shaking and behavioral symptoms induced by 5-methoxy-N,N,dimethyltryptamine in rats: comparison with some other 5-HT receptor antagonists.
abstract: The effect of the selective 5-HT3 receptor antagonists ICS 205-930 and MDL 72222 on head shaking behavior induced by L-5-HTP and behavioral symptoms induced with 5-methoxy-N,N,-dimethyltryptamine (5-MeODMT) in rats was evaluated. Both drugs dose-dependently reduced L-5-HTP-induced head shaking but were at least 600 times less potent than pirenperone and ketanserin and at least 50 times less potent than methysergide. ICS 205-930 and MDL 72222 were more than 1000 times less potent than pirenperone or methysergide and 100 times less potent than ketanserin in blocking 5-MeODMT-induced forepaw treading and tremor. Since it appears that head shakes induced by L-5-HTP are mediated by 5-HT2 receptors, these data suggest that ICS 205-930 and MDL 72222 do not significantly interact with 5-HT2 receptors in the brain. Furthermore, the data suggest that ICS 205-930 and MDL 72222 lack appreciable antagonistic activity at the 5-HT receptor(s) mediating those behavioral effects induced by 5-MeODMT.
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D008732:Methoxydimethyltryptamines / Q000494:pharmacology*; D008784:Methysergide / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000031:analogs & derivatives*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D014149:Tranquilizing Agents / Q000494:pharmacology; D014326:Tropanes / Q000494:pharmacology*; D000077526:Tropisetron
chemical_list: D007211:Indoles; D008732:Methoxydimethyltryptamines; D010880:Piperidines; D012702:Serotonin Antagonists; D014149:Tranquilizing Agents; D014326:Tropanes; D012701:Serotonin; D000077526:Tropisetron; D006916:5-Hydroxytryptophan; C042253:bemesetron; D008784:Methysergide; C034177:pirenperone