Differential development of ectopic testes based on their location in rats

ObjectiveIn order to investigate the effect of location on the development of ectopic testes, the relationship between the degree of degenerative change in ectopic testes and their original position was examined in rat models of cryptorchidism.Materials and methodsUnilateral ectopic testes were created by excising the future scrotal skin on either the right or left side in newborn rats. At 60 days of age, the position of the testes was examined, the testicular weight and seminiferous tubular diameter (STD) were measured, and spermatogenesis was evaluated using the Johnsen score.ResultsAll the rats showed maldescended testes on the operated side, with the testes descending into the superficial inguinal pouch, the perineum or the transverse contralateral scrotum. The testicular weight, STD and Johnsen score were all significantly lower for the superficial inguinal testes than for either the perineal or contralateral scrotal testes.ConclusionThese findings suggest that the degree of testicular degeneration depends on the position of the ectopic testes; the higher the testicular location, the greater the histological changes.