CU ZN SUPEROXIDE-DISMUTASE, CATALASE AND GLUTATHIONE-PEROXIDASE MESSENGER-RNA EXPRESSION IN THE RAT TESTIS AFTER SURGICAL CRYPTORCHIDISM AND EFFERENT DUCT LIGATION/

The testis is known to be highly sensitive to a number of physical str esses. Previous investigations suggest that oxidative stress may be an important mediator of testicular injury. The ability of the testis to manage oxidative stress may be limited by enzymatic clearance of reac tive oxygen species (ROS). To evaluate the ability of the testis to wi thstand the common pathologic conditions of cryptorchidism and obstruc tion, we measured mRNA levels of testicular antioxidant enzymes. Prepu bertal rats were rendered unilaterally cryptorchid and 40 days after t he procedure, cryptorchid, contralateral and control (sham) testes wer e harvested for RNA extraction. Adult rats were subjected to unilatera l efferent duct ligation and the obstructed testes harvested 1 to 28 d ays after the procedure. Antioxidant enzyme mRNA expression was assess ed by Northern blot analysis using P-32-labeled DNA probes for classic al cellular glutathione peroxidase (GSHPx), phospholipid hydroperoxide glutathione peroxidase (PHGPX), Cu/Zn superoxide dismutase (SOD) and catalase, In both cryptorchid and contralateral testes, the germ cell- specific 0.9 kb SOD and PHGPX mRNA transcript levels were significantl y decreased compared to control testes (p <0.05). Similarly, after eff erent duct ligation, the 0.9 kb SOD and PHGPX mRNA transcript levels a lso decreased compared to control testes (p <0.05). These findings sug gest that the overall decline in testicular mRNA transcript levels aft er efferent duct ligation and cryptorchidism is primarily due to germ cell depletion. Reduced levels of antioxidant enzyme mRNAs in cryptorc hid testes have been documented. Further experiments may elucidate the role of increased oxidative stress associated with decreased antioxid ants in cryptorchidism. It remains to be determined whether oxidative stress has a causative role in the abnormal spermatogenesis and tumori genesis associated with cryptorchidism.