青春期大鼠受己烯雌酚持续作用对成年后睾丸波形蛋白表达的影响

Effects on Pubertal Diethyl-stilbestrol Administration on Vimentin of Testis in Adult Rats

目的:探讨青春期大鼠受己烯雌酚(DES)持续作用,成年后睾丸曲细精管和间质区波形蛋白表达的影响。方法:将SD大鼠,随机分成对照组与3个DES实验组,对照组注射0.3ml纯玉米油,实验组分别注射含DES2μg·kg-1·d-1(低剂量组)、10μg·kg-1·d-1(中剂量组)、50μg·kg-1·d-1(高剂量组)的玉米油0.3ml,每组6只动物。各组隔日腹腔注射,28d后采集标本。采用免疫组化法观察睾丸波形蛋白的表达和变化。结果:在睾丸曲细精管内仅见波形蛋白表达于支持细胞胞浆,生精细胞中未见表达。在支持细胞中,波形蛋白由基膜基部绕核成环状,并随胞质呈辐射状向曲细精管管腔延伸。随着DES染毒剂量的增加,其表达变弱,向管腔的辐射状部分变短、消失。与对照组相比,DES实验组波形蛋白的阳性支持细胞表达率及表达量均显著下降(P<0.01),各实验组间比较均有显著性差异(P<0.01)。波形蛋白也见表达于睾丸间质区的间质细胞胞浆与结缔组织,3个实验组中的表达量分别与对照组相比均有显著性下降(P<0.01),低剂量组波形蛋白表达量与高剂量组相比也有显著减少(P<0.05)。各组波形蛋白在间质区的表达量均显著高于支持细胞胞浆的表达(P<0.01)。结论:青春期大鼠受DES持续作用后,成年大鼠睾丸支持细胞和间质区的波形蛋白表达量显著下降,且损伤呈剂量效应。

Objective： To investigate the expression of vimentin in adult rat testis after diethyl-stilbestrol （DES） exposure during puberty. Methods： Twenty-four male Sprague-Dawley rats, aged 6 weeks, were divided into four groups randomly. The control group was given 0.3 ml corn oil alone. Group low, middle and high were administered DES at the dose of 2, 10, 50 μg·kg^-·d^-1in 0.3 ml corn oil on alternate days, respectively.After 28 d, animals were killed to obtain testicular tissues. The expression of vimentin in testis was detected by immunohistochemisry method. Results： In the control group, strong positive expression of vimentin in rat testis was observed in the cytoplasm of Sertoli cells, and vimentin filaments were abundant around the nucleus, resulting in a clear zone free of organelles surrounding the nucleu. From this location, vimentin filaments radiated outwards to the cell periphery. In the apical region of Sertoli cells, individual bundles of vimentin filaments were prominent and aligned parallel to the long axis of apical crypts containing spermatid heads. Compared with the control group, the expression of vimentin was decrease with doses increase, representing shorten or no extending radicalized filaments towards the apical region of Sertoli ceils in group low, middle and high. The ratios of positive Sertoli cells and content of vimentin significantly decreased in all DES groups （P〈0.01）, and the same as compare within any two of group low, middle and high （P〈 0.01）. The expression was also showed in the cytoplasm of Leydig cells and connective tissue outside seminiferous tubule. Compared with control group, the content of vimentin in testicular intersitium had significant decrease in all DES groups （P〈0.01）; and compared with the low group, significant decrease of vimentin appeared in the high group （P〈 0.05）. The expression of vimentin in testicular interstitiurn was stronger than that in Sertoli cells, and there was significant difference among all groups （P〈0.01）. Conclusion： Expression of vimentin of Sertoli cells and testicular interstitiurn in male rat would be significantly decreased after pubertal DES exposme, and the effects were dosage-related.