assessment of testis histological changes and sperm parameters in experimentally–induced unilateral and bilateral cryptorchid mouse model

Background: in most mammals, the testis is always maintained at a lower temperaturethan that in the abdomen, and exposure of the testis to body temperature causesdegeneration of germ cells.objective: in this research, the long effect of heat exposure on sperm parameters andmicrostructure of mouse testis were investigated. cryptorchid mouse were induced byexposure to abdominal heat.materials and methods: immature mice were anesthetized and a small incision wasmade in the abdominal skin, then fat pad at the upper end of testis was sutured toperitoneum. weight of testis, spermatogenic cell numbers, tubular ectasis (rate oftubular lumen comparing to the thickness of germinal epithelium) as well as epididymalsperm parameters were measured.results: the results showed that spermatogenesis was arrested and testicular weights,seminiferouse tubular diameters and epididymal sperm parameters were significantlyreduced in the bilateral undescended testis compared with unilateral undescended testisand the control mice. however, complete depletion of seminiferous tubules and absenceof germ cells was not found in the animals.conclusion: in general, high temperature caused a decreased in all analyzed parametersexcept spermatogonial cell number probably due to the apoptosis and these changessignificantly increase in bilateral groups compared with unilateral groups. we believethat the present model is a suitable tool for enrichment of spermatogonial stem cells,also it is useful for treatment of cryptorchidism and further biological research onspermatogenesis.