title: Nicotine potentiates morphine antinociception: a possible cholinergic mechanism.
abstract: The effect of nicotine on morphine induced antinociception was studied using the tail-flick test. A low dose of nicotine (0.0001 mg/kg) which did not induce any antinociception, potentiated the morphine antinociceptive response dose-dependently. The opioid antagonist naloxone decreased the response of morphine and morphine plus nicotine. The muscarinic receptor antagonist atropine decreased the nicotine-induced potentiation of the morphine response. Sulpiride, pimozide, SCH 23390, phenoxybenzamine, propranolol, methysergide, metergoline, hexamethonium and mecamylamine did not alter the antinociception induced by nicotine and morphine. It is concluded that the potentiation of morphine-induced antinociception by nicotine may be mediated through a cholinergic mechanism.
authors.affiliation: Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Iran.
authors.forename: M R
authors.initials: MR
authors.lastname: Zarrindast
authors.forename: A B
authors.initials: AB
authors.lastname: Nami
authors.forename: D
authors.initials: D
authors.lastname: Farzin
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D010147:Pain Measurement / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D001552:Benzazepines; D018492:Dopamine Antagonists; D018722:Nicotinic Agonists; D009538:Nicotine; D009020:Morphine