中文摘要：

目的在建立大鼠海洛因辨别刺激模型基础上，评估不同浓度的尼古丁对海洛因辨别刺激的替代作用。方法采用固定比率食物强化方法训练雄性sD大鼠辨别0．3mg／kg海洛因；之后，分别给予不同剂量的海洛因、尼古丁替代0．3mg／kg海洛因，明确海洛因辨别效应曲线和尼古丁替代0．3mg／kg海洛因的辨别效应。结果0．3mg／kg剂量的海洛因能形成稳定的大鼠药物辨别行为；不同剂量海洛因替代组（0．03，0．1，0．3，0．56mg／kg）的海洛因鼻触响应率分别为（33．9±15．0）％，（43．3±13．3）％，（98．7±0．5）％，（99．4±0．2）％，海洛因剂量在0～0．3mg／kg之间诱导的辨别效应呈剂量依赖性增加；0．03，0．1mg／kg尼占丁替代组的海洛因鼻触响应率分别为（1．9±1．1）％，（13．7±5．6）％，与0．3mg／kg海洛因替代组相比，差异有统计学意义（P〈0．01）；而0．3，0．5mg／kg尼古丁替代组的海洛因鼻触响应率分别为（60．4±16．1）％，（65．9±16．4）％，与0．3mg／kg海洛因替代组相比，差异无统计学意义（P〉0．05）。结论0．3，0．5mg／kg尼古丁能产生部分类似海洛因的辨别刺激效应。

英文摘要：

Objective To evaluate the discriminative stimulus effects of nicotine on the basis of a rat model of heroin discrimination. Methods Male Sprague-Dawley rats were trained to discriminate 0.3 mg/kg heroin from saline under a fixed-ratio （FR10） schedule of food reinforcement. After training, different doses of heroin and nicotine were used to substitute for training dose of heroin, the dose-response curve for heroin and the discrimi- native stimulus effects of nicotine were identified in rats. Results All rats reliably discriminated 0.3 mg/kg heroin from saline. Different doses of heroin （ 0. 03 ,0.1,0. 3 ,0. 56 mg/kg） produced （ 33.9 ± 15.0 ） %, （ 43.3 ± 13.3 ） %, （98.7 ± 0.5 ） % , （99.4 ± 0.2 ） % total responding on heroin associated lever, heroin at the doses of lower than 0.3 mg/kg produced the dose-dependent relationship in heroin-appropriate responding. In heroin-trained rats, nicotine at the dose of 0.03,0.1 mg/kg produced（ 1.9 ± 1.1 ） % , （ 13.7 ±5.6） % total responding on heroin associated lever,there were extremely significant differences with 0.3 mg/kg heroin control （P〈 0.01 ）. However, nicotine at the dose of 0.3,0.5 mg/kg produced （ 60.4 ± 16.1 ） % , （65.9 ± 16.4） % total responding on heroin associated lever, there were no significant differences with 0.3 mg/kg heroin control （P 〉 0.05 ）. Conclusion Nicotine at the dose of 0.3,0.5 mg/kg can partially produce heroin-like discriminative stimulus effects.