Synergistic sedative effect of selective MAO-A, but not MAO-B, inhibitors and melatonin in frogs.
Total suppression of righting reflex in frogs (Rana pipiens, 25-35 mg b.w.) was observed after combined administration of melatonin (12.5 mg/kg) and selective inhibitors of MAO-A: clorgyline (2.5 mg/kg) and moclobemide (50 mg/kg) but not MAO-B: selegiline (25 mg/kg) and Ro-19-6327 (50 mg/kg). None of these drugs alone affected the righting reflex. Clorgyline and selegiline selectively inhibited brain MAO-A and MAO-B activity (by more than 90%), resp. Frogs might represent a convenient model to study the selective MAO-A and B type inhibitors since they provide the opportunity to correlate behaviour and biochemical changes induced by MAO inhibitors.
Requintina
P J
PJ
Pineal Research Laboratory, VAMC, Providence, Rhode Island.
Oxenkrug
G F
GF
Yuwiler
A
A
Oxenkrug
A G
AG
D000818:Animals; D001921:Brain / Q000187:drug effects; D004357:Drug Synergism; D005260:Female; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D011187:Posture; D011894:Rana pipiens; D012018:Reflex / Q000187:drug effects
D006993:Hypnotics and Sedatives; D008996:Monoamine Oxidase Inhibitors; D008995:Monoamine Oxidase; D008550:Melatonin