OBJECTIVE In this study, explored the pathologic mechanism of the contralateral testes impairment in unilaterally cryptorchid rats by investigating the gene expression level. METHODS Thirty male Sprague-Dawley rats were randomly and evenly divided into two groups: cryptorchid group and control group. Cryptorchidism was induced by surgical relocation. RT-PCR was then applied to examine the mRNA expression level of antioxidant enzymes in descended testes, including glutathione peroxidase (GSH-PX), copper/zinc-superoxide dismutase (Cu/Zn-SOD), and catalase (CAT). The concentration of malondialdehyde (MDA) was determined by spectrophotometry. In addition, germ-cell apoptosis was detected by a terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. RESULTS Two weeks after the operation, the mRNA expression levels of GSH-PX and Cu/Zn-SOD in the cryptorchid group were significantly downregulated; the expression of MDA, as well as the number of apoptotic germ cells, significantly increased compared to the control group (p < 0.01). The mRNA expression of CAT did not show significant changes (p > 0.05). CONCLUSION GSH-PX and SOD were downregulated in the testis contralateral to the undescended testis, leading to the accumulation of reactive oxygen species and germ-cell apoptosis. Our results may provide molecular explanations for the impairment of the descended testis in unilateral cryptorchidism.

中文翻译：

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对侧睾丸受损的对侧睾丸大鼠的抗氧化酶表达。

目的通过研究基因表达水平探讨单侧隐睾大鼠对侧睾丸对侧睾丸损伤的病理机制。方法30只雄性Sprague-Dawley大鼠随机分为两组，即隐睾组和对照组。隐睾症是由外科手术引起的。然后应用RT-PCR检测降级睾丸中抗氧化酶的mRNA表达水平，包括谷胱甘肽过氧化物酶（GSH-PX），铜/锌超氧化物歧化酶（Cu / Zn-SOD）和过氧化氢酶（CAT）。用分光光度法测定丙二醛（MDA）的浓度。另外，通过末端脱氧核苷酸转移酶dUTP缺口末端标记（TUNEL）测定法检测了生殖细胞凋亡。结果术后两周，隐睾组的GSH-PX和Cu / Zn-SOD的mRNA表达水平明显下调。与对照组相比，MDA的表达以及凋亡性生殖细胞的数量均显着增加（p <0.01）。CAT的mRNA表达没有显示出显着变化（p> 0.05）。结论GSH-PX和SOD在睾丸中相对于未下降的睾丸被下调，导致活性氧的积累和生殖细胞凋亡。我们的结果可能为单侧隐睾症中睾丸下降的损害提供分子解释。CAT的mRNA表达没有显示出显着变化（p> 0.05）。结论GSH-PX和SOD在睾丸中相对于未下降的睾丸被下调，导致活性氧的积累和生殖细胞凋亡。我们的结果可能为单侧隐睾症中睾丸下降的损害提供分子解释。CAT的mRNA表达没有显示出显着变化（p> 0.05）。结论GSH-PX和SOD在睾丸中相对于未下降的睾丸被下调，导致活性氧的积累和生殖细胞凋亡。我们的结果可能为单侧隐睾症中睾丸下降的损害提供分子解释。