Effect of nicotine on apomorphine-induced licking behaviour in rats.
In the present study, the dopaminergic receptor agonist apomorphine (0.1, 0.25 and 0.5 mg/kg) induced a dose-dependent licking in rats. Nicotine administration (0.025-250 microg/kg) altered the apomorphine-induced licking. The lower doses of nicotine (0.05 and 0.5 microg/kg) increased while the higher dose of the drug (250 microg/kg) reduced the apomorphine response. The antimuscarinic drug atropine (2.5 and 5 mg/kg) reduced the effects of apomorphine or nicotine plus apomorphine. The central nicotinic receptor antagonist mecamylamine (0.05, 0.25 and 0.5 mg/kg) also reduced the response induced by apomorphine or nicotine plus apomorphine. However, the peripheral nicotinic receptor antagonist hexamethonium (2.5, 5 and 10 mg/kg) reduced the response induced by nicotine plus apomorphine but not that elicited by apomorphine alone. The results indicate that the nicotinic receptor mechanism(s) may interact with apomorphine-induced licking in rats. Although central nicotinic and cholinergic mechanisms may be involved in the licking induced by apomorphine, peripheral nicotinic mechanism may be involved in the nicotine-induced increased apomorphine effect.
Zarrindast
M R
MR
Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Iran.
Shekarchi
M
M
Rezayat
M
M
D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D018680:Cholinergic Antagonists / Q000494:pharmacology; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D004347:Drug Interactions; D018738:Hexamethonium / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D051381:Rats; D013239:Stereotyped Behavior / Q000187:drug effects*
D018680:Cholinergic Antagonists; D018491:Dopamine Agonists; D018727:Muscarinic Antagonists; D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; D018738:Hexamethonium; D008464:Mecamylamine; D009538:Nicotine; D001285:Atropine; D001058:Apomorphine