Zarrindast M R, Shekarchi M, Rezayat M
Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Iran.
Eur Neuropsychopharmacol. 1999 Mar;9(3):235-8. doi: 10.1016/s0924-977x(98)00027-3.
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.
在本研究中，多巴胺能受体激动剂阿扑吗啡（0.1、0.25和0.5毫克/千克）在大鼠中诱发了剂量依赖性的舔舐行为。给予尼古丁（0.025 - 250微克/千克）改变了阿扑吗啡诱发的舔舐行为。较低剂量的尼古丁（0.05和0.5微克/千克）增强了阿扑吗啡的反应，而较高剂量的尼古丁（250微克/千克）则减弱了阿扑吗啡的反应。抗毒蕈碱药物阿托品（2.5和5毫克/千克）减弱了阿扑吗啡或尼古丁加阿扑吗啡的作用。中枢烟碱受体拮抗剂美卡拉明（0.05、0.25和0.5毫克/千克）也减弱了阿扑吗啡或尼古丁加阿扑吗啡诱发的反应。然而，外周烟碱受体拮抗剂六甲双铵（2.5、5和10毫克/千克）减弱了尼古丁加阿扑吗啡诱发的反应，但不减弱阿扑吗啡单独诱发的反应。结果表明，烟碱受体机制可能与大鼠中阿扑吗啡诱发的舔舐行为相互作用。虽然中枢烟碱和胆碱能机制可能参与了阿扑吗啡诱发的舔舐行为，但外周烟碱机制可能参与了尼古丁诱发的阿扑吗啡作用增强。
