尾悬吊状态对性成熟期雄性大鼠生殖功能的影响

目的:探讨尾悬吊造成的模拟失重状态对性成熟期雄性大鼠生殖功能的影响及其机制,为研究太空环境对人类生殖功能的影响打基础。方法:性成熟期健康SD雄性大鼠40只,随机分为4组,每组10只,分为实验1组(尾悬吊14 d)、实验2组(尾悬吊28 d)和对照1组(自由活动14 d)、对照2组(自由活动28 d),观察睾丸的重量和形态学改变、精子数量和质量改变、血液中激素含量的改变,并利用原位缺口末端标记法(TUNEL)检测睾丸细胞的凋亡。结果:各悬吊组大鼠睾丸重量与相应对照组相比明显下降(P<0.05),附睾精子数量和活动率明显减少(P<0.05),精子畸形率和凋亡率明显增加(P<0.05),卵泡刺激素和黄体生成素轻度增高,而睾酮含量明显下降(P<0.05)。但上述变化在悬吊14 d组和28 d组之间无明显差异(P>0.05)。另外,悬吊组睾丸组织生精小管萎缩,生精上皮细胞层数逐渐减少,管腔内的精子数明显减少,悬吊28 d组比悬吊14 d组改变更明显。结论:模拟失重对性成熟期雄性大鼠生殖功能有较明显的损害,这种损伤可能与引起睾丸生精细胞凋亡有关。抑制睾丸生精细胞凋亡也许可以防护失重状态下的生殖损害。

Effect of Tail-suspension on the Reproduction of Adult Male Rats

Objective: To study the effects on the male reproduction in adult male rats and its mechanisms through simulated weightlessness using tail-suspension,in order to do a basic works of exploring the effects on human being's reproduction in outer space.Methods: Forty Spraque-Dawley adult male rats were randomly divided into four groups,two experimental groups and two control groups.Rats in the two experimental groups were tail-suspended for 14 d and 28 d respectively,then we examined the weight and morphology of testis,the quality and amount of sperm,also tested the serum hormone by radioimmunoassay and analyzed apoptosis rate of testicular cells by TUNEL in the experimental rats and control rats.Results: After tail-suspension,the weight of testis,the sperm count and sperm motility significantly decreased(P<(0.05)),while the apoptosis rate of testicular cells and the amount of abnormal sperm markedly increased(P<(0.05)).The content of testosterone significantly decreased(P<(0.05)),but the contents of FSH and LH mildly increased(P>(0.05)).These changes were not significant between two experimental groups(P>(0.05)).In addition,the seminiferous tubules became atrophy with the reduction of the layers of seminiferous epithelium,and sperm amount in lumens of seminiferous tubules decreased in experimental groups.The above were more remarkable in the 28 d experimental group. Conclusion: Simulating weightlessness has a harmful effect on reproduction of adult male rats.These may be caused by inducing apoptosis.The blocking apoptosis of testicular cells may be useful in improving the harmful effect.