Antagonism by naloxone of anti-tremorine effect of bromocriptine in mice.
Effects of the opioid antagonist naloxone (10 mg/kg) and its interaction with anticholinergic (scopolamine) and dopaminergic (bromocriptine) agents against tremorine-induced tremors was studied. Naloxone (10 mg/kg) per se gave significant protection and significantly potentiated the protective effect of scopolamine against tremorine-induced tremors at 5 min only. When naloxone and subeffective dose of bromocriptine (2 mg/kg) were administered simultaneously, instead of protection, an enhancement of tremorogenic activity was seen. Although the exact mechanism of this drug interaction is far from clear, a multireceptor involvement (i.e. opioid, dopaminergic and cholinergic type) in the modulation of tremorine-induced tremors in mice has been speculated.
D000818:Animals; D001971:Bromocriptine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology*; D012601:Scopolamine / Q000494:pharmacology; D014202:Tremor / Q000139:chemically induced; D014203:Tremorine / Q000037:antagonists & inhibitors*
D009270:Naloxone; D001971:Bromocriptine; D012601:Scopolamine; D014203:Tremorine