吗啡耐受对雄性大鼠生精功能影响的初步探讨

目的:研究在吗啡耐受模型中吗啡治疗疼痛时,对雄性大鼠的生殖能力造成的影响,并探讨其机制。方法:20只SD雄性大鼠,体重200~250 g,随机分为2组,Ⅰ组对照组,Ⅱ组吗啡耐受组,第一天行行为学测试,测定大鼠基础热缩足潜伏期(PWTL),然后皮下注射吗啡10 mg/kg,计算30 min时各组大鼠吗啡的MPE值。第2天,Ⅰ组注射生理盐水,每天2次;Ⅱ组皮下注射吗啡10 mg/kg,每天2次;Ⅰ组和Ⅱ组连续注射7 d,皮下注射时间为每天8:00和17:00,第7天进行行为学测试,方法同第1天。行为学检测完毕立即处死大鼠,留取附睾,对附睾尾进行精子计数;睾丸,采用免疫组织化学检测Bax和Caspase-3的表达。结果:第1天两组大鼠基础热痛阈和MPE值无明显差异。第7天两组大鼠的基础热痛阈无明显差异,但与Ⅰ组相比,Ⅱ组的MPE值降低(P0.05);说明吗啡耐受模型制作成功,精子计数显示,吗啡耐受组精子相对数目明显减少(P0.05),睾丸组织切片中,吗啡组Bax和Caspase-3的阳性表达都高于对照组。结论:吗啡耐受模型中,雄性SD大鼠的精子相对数目减少,吗啡组Bax和Caspase-3的阳性表达都高于对照组,由此推测,吗啡耐受可能通过上调Bax和Caspase-3增加雄性大鼠生殖系统的细胞凋亡,影响精子浓度。

Impact of morphine on the reproductivity of male rats

Objective： To explore the effect of morphine on male reproductive ability and its mechanisms in the rat model of morphine tolerance. Methods： Twenty male SD rats were equally randomized to groups Ⅰ （control） and Ⅱ （morphine tolerance）. On the 1st day, the basic paw withdrawal thermal latency （PWTL） was obtained from all the rats followed by subcutaneous injection of morphine at 10 mg/kg and then calculation of the percentage of the maximal possible effect （MPE） at 30 min after administration. On the 2nd day, the rats of group Ⅰ were injected subcutaneously with saline and those of group Ⅱ with morphine at 10 mg/kg bid for 7 days. Then all the rats were killed after behavioral tests and their testes and epididymides harvested for sperm counting and determination of the expressions of Bax and Caspase-3 by immunohistochemistry. Results ： On the 1 st day, no obvious differences were observed between the two groups in the basic PWTL or the percentage of MPE. On the 7th day, the percentage of MPE was significantly decreased in group Ⅱ as compared with group Ⅰ （ P 〈 0.05 ） , while the basic PWTL showed no marked difference between the two groups. Group 11 also exhibited a significantly reduced epididymal perm count （ P 〈 0.05 ） and remarkably upregulated expressions of Bax and Caspase-3 in comparison with group Ⅰ . Conclusion： Morphine might increase testicular cell apoptosis and reduce sperm concentration by upregulating the expressions of Bax and Caspase-3 in the rat model of morphine tolerance.