单侧隐睾对侧睾丸损害机制的实验研究

The mechanism of contralateral testicular impairment induced by unilateral cryptorchid in rats

目的 神经分子水平方面探讨单侧隐睾鼠对侧睾丸损害的机制。方法 30只SD雄性大鼠,分为对照组(A组)、隐睾组(B组)、隐睾加生殖股神经(GFN)切断组(C组)。每组各10只。免疫组化技术观察降钙素基因相关肽(CGRP)阳性细胞的神经分布;生物素-dUTP/酶标亲和素测定法检测睾丸生殖细胞凋亡;透射电镜观察Sertoli细胞的超微结构;化学比色法测定丙二醛(MDA)的含量。结果 A组睾丸中含有大量CGRP的神经细胞。术后90d,与A组比较,B组对侧睾丸CGRP明显降低,MDA升高,细胞凋亡增加(P<0.01),Sertoli细胞有缺血性改变。C组的这种损害减轻(P<0.01)。结论 单侧隐睾鼠对侧睾丸的损害是通过隐睾GFN传入到交感神经,反射性引起对侧睾丸CGRP降低,睾丸缺血缺氧,氧自由基升高,生殖细胞凋亡增加所引起的。

Objective To investigate the mechanism of contralateral testicular impairment induced by unilateral cryptorchid in rats. Methods Thirty male Sprague Dawley rats were averagely divided into 3 groups: Group A, control group, Group B, cryptorchid group and Group C, cryptorchid combined with genitofemoral nerve (GFN) resection. The distribution of CGRP immunoreactive nerve fibers in testes was evaluated by means of immunohistochemical staining. Germ cell apoptosis was detected by terminal-de- oxynucleotidyl transferase mediated d-UTD nick end labeling. The concentration of malonic diethyl alde- hyde (MDA) in testes was measured by spectrophotometric determination. The ultra - structure of sertoli cells was observed under transmission electron microscopy. Results Compared with group A, the expres- sion of CGRP in the testes of group B was decreased significantly, while the level of MDA and the number of apoptotic germ cell were increased significantly in this group after 90 days of operation (P < 0.01). However, the expression of CGRP in the testes of group C was higher while the level of MDA and the number of apoptotic germ cell were lower than those in group B (P < 0.01). Conclusion Germ cell apop- tosis induced by CGRP reduction after GFN reflex might be responsible for the contralateral testicular im- pairment in unilateral cryptorchid in rats.