5-Hydroxytryptamine antagonists and the 5-methoxy-N,N-dimethyltryptamine-induced changes of postdecapitation convulsions.
The ability of various compounds to antagonise the 5-MeODMT induced prolongations of latency and duration of postdecapitation convulsions (PDCs) were compared. The 5-hydroxytryptamine (5-HT) receptor antagonists, mianserin, methergoline, cinanserin and methysergide antagonised the 5-MeODMT (0.5 to 4.0 mg/kg) induced prolongations of latency to onset of convulsions substantially and to a lesser extent the prolongation of duration. The efficacy of the 5-HT antagonists for blocking 5-MeODMT changes of PDCs was roughly of the order mianserin greater than cinanserin greater than methysergide greater than methergoline. Pirenperone, the 5-HT2 antagonist, and pimozide, the dopamine receptor antagonist did not antagonise the 5-MeODMT induced changes. Mianserin, methergoline, cinanserin and methysergide, by themselves, prolonged the duration of PDCs but did not affect latency. Pirenperone (0.25 mg/kg) prolonged both the latency and duration of the PDCs while pimozide (0.5-2.0 mg/kg) had no effect upon PDCs. This evidence suggests that 5-MeODMT induced changes of PDCs are mediated via 5-HT1 receptors and thus a reliable model to combine with other measures of spinal function is suggested.
D000818:Animals; D003655:Decerebrate State; D008297:Male; D008636:Mesencephalon / Q000503:physiopathology; D008732:Methoxydimethyltryptamines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000503:physiopathology* / Q000517:prevention & control; D012701:Serotonin / Q000031:analogs & derivatives*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013116:Spinal Cord / Q000503:physiopathology*
D008732:Methoxydimethyltryptamines; D012702:Serotonin Antagonists; D012701:Serotonin