光照应激对雄性大鼠生殖相关参数的影响

目的 观察比较光照应激状态下不同应激时间段SD大鼠生殖相关参数的变化.方法 建立SD大鼠的光照应激模型分为光照应激短期(2d、3d、4d、7d)和光照应激长期(14d、21d、28d),并分别取应激状态下SD大鼠睾丸、附睾称重,对附睾尾精子计数,HE染色观察睾丸结构,应用免疫组织化学和westernblot分析3 β-HSD表达,比较各实验组和对照组问上述指标的变化.结果 短期光照应激组(2d、3d、4d、7d)与对照组相比,大鼠体重、睾丸重量、附睾重量、精子数量没有明显变化(P>0.05),HE染色显示睾丸结构无明显变化,免疫组化和western blot显示3β-HSD表达无明显变化.长期光照应激组与对照组相比,大鼠重量、睾丸和附睾重量都有明显增加.与对照组相比,14 d实验组的附睾重量有显著性差异(P<0.05):21 d、28 d实验组的睾丸重量有显著差异(P<0.05),21 d、28 d实验组的体重、附睾重量和精子相对计数都有极显著差异(P<0.01).HE染色显示睾丸内生精小管变粗,管腔内生精细胞增多,免疫组化和western blot显示长期应激组14 d的3β-HSD相对表达量增加20.3%,有显著性差异(P<0.05);21d和28d实验组3β-HSD的相对含量分别增加30.4%和43.3%,差异极显著(P<0.01).结论 短期光照应激不能破坏大鼠机体内稳态的调节机制,对生殖的影响并不明显;而长期处于光照应激状态下的雄性大鼠,超出机体内稳态的调节能力,对生殖的影响不仅表现在体重、睾丸、附睾和附睾尾的重量增加,而且精子相对计数及睾丸结构都发生相应变化,3β-HSD表达量也明显增加.提示光照是影响大鼠生殖功能的一个因素.

Effect of stress induced by constant-light on the parameters related to reproduction of rats

Objective To investigate the changes of the weight of body,testis and epididymis,the spermtozoon numbers.the expression of 3β-HSD in rat testis ander constant-light stress.Methods Rat models with stress induced by constant-light were first established,and then they were divide into GroupA with short constant-light stress(2d,3d,4 d,7 d)and GroupB with chronic constant-light stress(14 d,21 d,28 d).The testis and epididymis of rat in stress group and control groups were collected respectively.The weight of testis and epididymis was measured and the number of spermtozoon from the caudal epididymis was countered.HE staining,immunohistochemistry and western blot was applied to observe the structure of testis and the change of 3 β-HSD expression in rat.testis.Results Comparing with those of the control group,body weight,weight of testis and epididymis,number of spermatozoon of the rats in short constant-light stress group (2 d,3 d,4 d,7 d)did not change significantly(P＞0.05),the structure of testicle and the expression of 3 β-HSD in testis did not change too.Comparing with that of the control group,body weight,weight of testis and epididym and number of spermatozoon of the rats in chronic constant-light stress group(14 d,21 d,28 d)were remarkable increased(P＜0.05,P＜0.01),and thick somniferous tubule in testicle and many,spermatogenesis cells in lumina were observed by histochemistry analysis.The expressions of 3 β-HSD in rat testis in the 14,21 and 28 day group were increased by 20.3%,30.4% and 43.3% fold respectively (P＜0.05,P＜0.01,P＜0.01).Conclusion No significant changes in the reproduction of rats were found under short constant-light stress,which was related to the adjustment of homeostasis.But the chronic constant-light stress not only affected the weight of body,testis and epididym but also affected sperm numbers and testicular structure.It indicated that chronic constant-light stress was an important factor for reproductive function changes of male rats.