Antioxidant Enzymes Expression of the Impaired Contralateral Testes in Unilaterally Cryptorchid Rats.

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.