Zarrindast M R, Pazouki M, Nassiri-Rad S
Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Iran.
Pharmacol Toxicol. 1997 Nov;81(5):209-13. doi: 10.1111/j.1600-0773.1997.tb00048.x.
In this work we have studied the influences of nicotinic agents on the antinociception of morphine in formalin test. Nicotine (0.001-0.1 mg/kg) induced antinociception in mice in a dose-dependent manner in the early phase of formalin test, and also potentiated the morphine effect. The nicotinic receptor antagonist, mecamylamine (0.5 mg/kg), but not hexamethonium decreased the antinociception induced by nicotine (0.1 mg/kg) in both phases. The muscarinic receptor antagonist atropine (5 and 10 mg/kg) also decreased the response of nicotine. Mecamylamine, hexamethonium or atropine did not alter morphine antinociceptive response, while naloxone decreased responses induced by nicotine or morphine. The antagonists by themselves did not elicit any response in formalin test, however, high does of mecamylamine tend to increase pain response. It is concluded that central cholinergic and opioid receptor mechanisms may be involved in nicotine-induced antinociception.
在本研究中，我们研究了烟碱类药物对福尔马林试验中吗啡镇痛作用的影响。尼古丁（0.001 - 0.1毫克/千克）在福尔马林试验早期以剂量依赖的方式诱导小鼠产生镇痛作用，并且还增强了吗啡的作用。烟碱受体拮抗剂美加明（0.5毫克/千克）而非六甲铵在两个阶段均降低了尼古丁（0.1毫克/千克）诱导的镇痛作用。毒蕈碱受体拮抗剂阿托品（5和10毫克/千克）也降低了对尼古丁的反应。美加明、六甲铵或阿托品并未改变吗啡的镇痛反应，而纳洛酮降低了尼古丁或吗啡诱导的反应。拮抗剂本身在福尔马林试验中未引发任何反应，然而，高剂量的美加明倾向于增加疼痛反应。结论是，中枢胆碱能和阿片受体机制可能参与尼古丁诱导的镇痛作用。
