吗啡处理大鼠的戒断症状以及血浆吗啡及其代谢物M3G含量的性别差异

本文旨在评价阿片依赖行为是否存在性别差异。纳洛酮催促戒断研究：20只大鼠,单次注射吗啡后1小时注射纳洛酮。评价大鼠戒断症状,同时应用HPLC-UV方法测定血浆中吗啡和M3G浓度。自然戒断研究：97只大鼠,吗啡组以剂量递增法给药28天,于最后一次给药后,评价大鼠自然戒断症状和血浆中吗啡以及M3G的含量。急性给药催促戒断的戒断症状未观察到性别差异。自然戒断后身体戒断症状存在性别差异,雄鼠重于雌鼠（P〈0.05）。在急性给药实验和慢性给药实验中,吗啡的Cmax雄鼠比雌鼠含量高,M3G的Cmax雌鼠比雄鼠含量高。吗啡药代动力学特征在急性给药实验和慢性给药实验中存在性别差异。成瘾大鼠自然戒断后身体戒断症状的程度和血浆中吗啡、M3G浓度以及M3G/MOR的比值相关。

Sex differences in morphine dependence and plasma levels of morphine and morphine-3-glucuronide in rats

To examine whether there are sex differences in morphine dependence and its metabolism. Naloxone-precipitated withdrawal study was performed. Twenty rats were induced by naloxone 1 h after a single dose of morphine injection. The withdrawal syndromes were recorded and an HPLC-UV method was set up to quantify the plasma levels of morphine and morphine-3-glucuronide（M3G）. In the spontaneous withdrawal study, 97 rats were treated with progressive morphine for 28 d to develop physical dependence. The spontaneous withdrawal syndromes were recorded and plasma levels of morphine and M3G were determined after the last injection. No significant differences were observed in withdrawal syndrome of naloxone precipitating. More severe spontaneous withdrawal syndromes were produced by chronic morphine injection in male rats than in female rats（P0.05）. Higher maximum plasma concentration（Cmax） of morphine was measured in male rats than female rats, while female rats had higher Cmax of M3G than male rats in both acute and chronic morphine administration. Our results indicated that sex differences existed in withdrawal syndrome of morphine-dependent rats, and the pharmacokinetics of morphine showed sex difference by both acute and chronic administration. There might be a relationship between the severity of withdrawal syndrome and the plasma concentrations of morphine, M3G, and the ratio of morphine to M3G（M3G/MOR）.