Ren Y H, Zheng J W
National Institute on Drug Dependence, Beijing Medical University, Beijing 100083, China.
Acta Pharmacol Sin. 2000 Oct;21(10):924-6.
To study the potential of the psychological dependence of tramadol.
Rats were trained to discriminate 4.0 mg/kg morphine, and to discriminate 0.5 mg/kg methamphetamine (MA) from saline under a fixed-ratio (FR10) schedule of reinforcement. After they acquired the discrimination, different doses of tramadol were used to substitute for training dose of morphine and MA. Naltrexone was injected concomitantly with tramadol.
Tramadol fully substituted morphine at a dose of 32 mg/kg or higher. The ED50 value of the discriminative effects of tramadol was 20.94 mg/kg, higher than that of morphine (2.04 mg/kg, P < 0.01). MA failed to generalize to tramadol at the doses tested. Naltrexone antagonized the discriminative response of tramadol.
Tramadol can substitute for morphine in morphine discriminative rats. The discriminative stimulus effects of tramadol are mediated by a mu opioid mechanism.
研究曲马多产生心理依赖的可能性。
训练大鼠在固定比率（FR10）强化程序下区分4.0毫克/千克吗啡，并区分0.5毫克/千克甲基苯丙胺（MA）与生理盐水。在它们获得辨别能力后，使用不同剂量的曲马多替代吗啡和MA的训练剂量。同时注射纳曲酮与曲马多。
曲马多在32毫克/千克或更高剂量时完全替代吗啡。曲马多辨别效应的ED50值为20.94毫克/千克，高于吗啡（2.04毫克/千克，P<0.01）。在所测试的剂量下，MA未能泛化到曲马多。纳曲酮拮抗曲马多的辨别反应。
曲马多可在吗啡辨别大鼠中替代吗啡。曲马多的辨别刺激效应由μ阿片类机制介导。
