Possible involvement of opioid receptors in moclobemide-induced hypothermia in mice.
Effect of moclobemide, a selective monoamine oxidase-type A enzyme inhibitor, was investigated on the body temperature of male mice. Moclobemide (15-30 mg kg(-1), i.p.) produced significant reductions of body temperature in both normal and yeast-induced hyperthermic male mice. The hypothermic effect of moclobemide was moderate and short-lasting. Moclobemide-induced hypothermia was not antagonized by previous administration of prazosin (10 and 20 mg kg(-1), s.c.), propranolol (5, 10, and 20 mg kg(-1), s.c.), haloperidol (2 and 10 mg kg(-1), s.c.), atropine (10 and 20 mg kg(-1), s.c.), mepyramine (25 and 50 mg kg(-1), s.c.), or methysergide (0.5, 1, and 2 mg kg(-1), s.c.). Pretreatment with the opioid antagonist naloxone (10 mg kg(-1), s.c.), however, was able to reverse the hypothermic effect of moclobemide (30 mg kg(-1), i.p.) in both normal and yeast-induced hyperthermic mice. The present results indicate a possible role for central opioid receptors in the hypothermic effect of moclobemide. Also, a peripheral component for this effect of moclobemide at the mitochondria of peripheral tissues is suspected. The peripheral tissue mitochondria could be considered a common target for moclobemide and opioids actions on body temperature.
Ginawi
O T
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Department of Pharmacology, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. otginawi@hotmail.com
D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005334:Fever / Q000503:physiopathology; D007035:Hypothermia / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D051379:Mice; D020912:Moclobemide / Q000494:pharmacology*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D011957:Receptors, Opioid / Q000187:drug effects* / Q000502:physiology; D012441:Saccharomyces cerevisiae; D012737:Sex Factors
D008996:Monoamine Oxidase Inhibitors; D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D009270:Naloxone; D020912:Moclobemide; D008784:Methysergide