Induction of Spermatogenesis in the Naturally Cryptorchid Pig

Impaired expression of peroxiredoxin 4 in damaged testes by artificial cryptorchidism

“…The involvement of p53-dependent and -independent pathways have been proposed for apoptosis caused by artificial cryptorchidism. 7 By cooling, testes with cryptorchidism were able to produce spermatozoa, 8 which suggests temperature as the sole causal factor for apoptosis. That spermatogenic cell loss is concomitant with the decrease in the level of the unprocessed form of Prx4 is consistent with the contribution of this particular form to the spermiogenic process.…”

The prevention of orchiopexy-induced testicular lesions in the pig

“…Maintenance of the poor histologic appearance in the testes of naturally cryptorchid pigs subjected to orchiopexy supports this theory [6]. On the other hand, artificial cooling of abdominal testes in adult pigs with spontaneous unilateral cryptorchidism resulted in complete differentiation of the Offprint requests to: Dr. M. T. Frankenhuis, Department of Anatomy, School of Veterinary Medicine, State University, Yalelaan 1, 3508 TD Utrecht, The Netherlands spermatogenic epithelium in many seminiferous tubules [7]. In both experimental conditions normal testicular temperatures were achieved.…”

The p53/Retinoblastoma-mediated Repression of Testicular Orphan Receptor-2 in the Rhesus Monkey with Cryptorchidism

“…Early reports suggested that p53-mediated apoptosis in testis could be a result of unrepairable DNA damage induced by high temperatures, which provides a protective mechanism in the human and in other species for the avoidance of propagation of damaged DNA. The direct linkage between p53-mediated apoptosis in cryptorchid testis and male infertility and the mechanisms behind reversal of cryptorchidism-related infertility via lowering of the testis temperature remain unclear (4,5). Perhaps p53 could mediate other nonapoptotic signal pathways that play essential roles in spermatogenesis.…”

“…Cryptorchidism, the failure of the testes to descend into the scrotum at birth, affects 1% of newborn boys in the United States (2) and reports suggest that the worldwide incidence is rising (3). The subsequent infertility associated with cryptorchidism is attributed to testicular suprascrotal temperature, because in situ cooling of abdominal testes in dogs and pigs results in normal spermatogenesis (4,5). In mice, spermatogenesis ceased when the testis was displaced surgically into the abdominal cavity and then was restored when the testis was surgically returned back into the scrotum (6).…”