The inhibition of A and B forms of MAO in the production of a characteristic behabioural syndrome in rats after 1-tryptophan loading.
1-Tryptophan was administered to rats pretreated  with selective inhibitors of the A and B forms of MAO deprenyl, a selective inhibitor of MAO-B, produced minor changes in behaviour and in the concentrations of apparent 5-HT and 5-HAA in brain. High doses of clorgyline, a  selective inhibitor MAO-A, produced a characteristic stereotyped syndrome of hypermotility and tremor as well as an increase in apparent 5-HT and a decrease in apparent 5-HIAA in brain. Small doses of deprenyl and clorgyline in combination, but not singly, produced maximal effects on behaviour as well as on the concentrations of apparent 5-HT and 5-HIAA in brain. Maximum behavioural and biors before the other. It is concluded that the syndrome may be dependent on the formation of an N-substituted derivative of 5-HT which is at least partly deaminated by MAO-B. Alternatively, the syndrome may be dependent on a sufficiently high concentration of 5-HT in a special compartment where it is partly deaminated by MAO-B.
D000480:Alkynes / Q000494:pharmacology; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D003010:Clorgyline / Q000494:pharmacology; D004357:Drug Synergism; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000032:analysis; D006948:Hyperkinesis / Q000139:chemically induced*; D008297:Male; D008996:Monoamine Oxidase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D009526:Nialamide / Q000494:pharmacology; D010627:Phenethylamines / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000032:analysis; D013239:Stereotyped Behavior / Q000187:drug effects; D014202:Tremor / Q000139:chemically induced*; D014364:Tryptophan / Q000494:pharmacology*
D000480:Alkynes; D008996:Monoamine Oxidase Inhibitors; D010627:Phenethylamines; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan; D003010:Clorgyline; D009526:Nialamide