Enhancement of morphine antinociception by ibogaine and noribogaine in morphine-tolerant mice.
The effects of ibogaine, an alkaloid isolated form the bark of the African shrub, Tabernathe iboga, and noribogaine, a metabolite of ibogaine, on morphine antinociception were determined in male Swiss-Webster mice. Mice were rendered tolerant to morphine by implanting them with a pellet containing 25 mg of morphine base for 3 days. Placebo pellet-implanted mice served as controls. The antinociception of morphine (10 mg/kg, s.c.) was determined alone or in combination with an appropriate dose of ibogaine or noribogaine. Tolerance to morphine developed as a result of morphine pellet implantation as evidenced by decreased antinociceptive response to morphine. Both ibogaine and noribogaine dose-dependently enhanced morphine antinociception in morphine-tolerant but not in morphine-naive mice. It is concluded that ibogaine and noribogaine enhance morphine antinociception in morphine-tolerant mice.
Sunder Sharma
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Department of Pharmaceutics and Pharmacodynamics (M/C 865), The University of Illinois at Chicago, Health Sciences Center, Chicago, Ill., USA.
Bhargava
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HN
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004343:Drug Implants; D004357:Drug Synergism; D004361:Drug Tolerance; D006213:Hallucinogens / Q000008:administration & dosage / Q000494:pharmacology*; D007050:Ibogaine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D010146:Pain / Q000188:drug therapy*
D000701:Analgesics, Opioid; D004343:Drug Implants; D006213:Hallucinogens; D007050:Ibogaine; D009020:Morphine; C094385:noribogaine