Abstract
The histological development of both the undescended testes and their contralateral scrotal mates were investigated in two different rat models of unilateral cryptorchidism. In group I (8 rats), endocrinological unilateral cryptorchidism was obtained through the injection of the pregnant dames with the antiandrogen flutamide. In group II (14 rats), mechanical unilateral cryptorchidism was obtained by extra-abdominal fixation of the gubernaculum of the newborn rats. In group III (6 rats), non treated rats were used as controls. At the age of 90 days, the testicular weight, the seminiferous tubular diameter (STD) and the spermatogenesis evaluated by the Johnsen score method were examined in all of the rats. They were all significantly reduced in the undescended testes compared to those of the control testes, although there was no significant difference in these parameters for the undescended testes between group I and II. By contrast, the testicular weight, STD and the Johnsen score of the contralateral testes were all significantly reduced in group I compared to those of groups II and III. There was no significant difference in these parameters of the scrotal testes between groups II and the normal rats.