Objective  To investigate the effect of location of the testis on both testicular development and fertility in unilateral cryptorchidism. Material and methods  Forty‐nine Wistar King A newborn male rats were divided into three groups. In group 1 (15 rats) intra‐abdominal unilateral cryptorchidism were created by the intra‐abdominal fixation of the testis in the neonatal period. In group 2 (16 rats) extra‐abdominal unilateral cryptorchidism was created by extra‐abdominal fixation of the gubernaculum in the neonatal period. In group 3, 18 rats underwent a sham operation as controls. At 90 days of age, fertility was then assessed in each rat by housing it with two mature virgin females for 2 weeks. Thereafter, at 115–120 days of age, the rats were killed and their testes removed for histological examination. Results  There was no significant difference in the pregnancy rate between females coupled with rats from any group, but the mean number of offspring was significantly lower in females coupled with rats in group 1 than in group 2. Furthermore, histological examination of both the cryptorchid and contralateral scrotal testes showed more severe changes in the intra‐abdominal than the extra‐abdominal testes. Conclusion  These results suggest that intra‐abdominal cryptorchid testes are significantly more impaired than extra‐abdominal cryptorchid testes, and that such impairment might be caused by exposure of the testis to a higher temperature. The more severely impaired undescended testes may thus induce the degeneration of the contralateral scrotal testis and thereby cause subfertility in the intra‐abdominal unilateral cryptorchid rat model.

Objective To investigate whether the division of the cryptorchidism was significantly higher in the 90-180-day-old mature rats than in 30-day-old preproximal genitofemoral nerve (GFN) in neonatal rats induces testicular undescent or ascent in adulthood.pubertal rats (P<0.01). The mean (sd) weight of the undescended testes, at 2.36 (0.21) mg/g body weight, Materials and methods Neonatal Wistar King A rats underwent a unilateral proximal GFN transection on was significantly less than that of the contralateral scrotal testes, at 3.83 (0.23) mg/g; P<0.01) and of either the right or left side. At the age of 30 days, testicular descent was examined in all rats and the the control testes at the age of 90-180 days. In the sham-operated rats, all testes were located at the position of the testis recorded. The animals were allowed to develop further and the position of the bottom of the scrotum at 30 days of age and no rats showed any testicular ascent thereafter. testis re-examined at the age of 90-180 days, when the testes were removed and weighed. Sham-operatedConclusions The proximal division of the GFN in neonatal rats not only causes inguinoscrotal testicular malrats were used as controls.Results At the age of 30 days, four of the 46 (9%) descent but may also induce testicular ascent in adulthood. Testicular ascent may thus be caused by some operated rats showed a unilateral undescended testis on the operated side. At the age of 90-180 days, 43 intrauterine disorders of the GFN in patients with ascending testis. rats were re-examined (three rats died before re-examination); 34 (79%) of these rats showed undeKeywords Ascending testis, genitofemoral nerve, rat scended testes on the operated side. The occurrence of induced cryptorchidism, although Clarnette et al. [11] Introduction and Han and Choi [12] reported that accurate division of the GFN did not cause undescended testes. In the Several authors have described ascending testes as a new variant of cryptorchidism in which the testis once present study, we investigated whether division of the proximal GFN in neonatal rats induced testicular ascent descends into the scrotum in early infancy and then later spontaneously ascends out of the scrotum [1][2][3][4][5][6][7][8].in adulthood. However, the mechanism involved in spontaneous testicular ascent is still not completely understood. Some Materials and methods authors have postulated that the absorption of the processus vaginalis would retract the testis [2], whileWistar King A newborn rats, used within 72 h after birth, were obtained from a colony maintained at Kyushu other authors suggested that a failure of the natural elongation of the spermatic cord may cause spontaneous University and anaesthetized with ether. Forty-six rats underwent a laparotomy through a small transverse ascending testes [1].On the other hand, the genitofemoral nerve (GFN) has lower abdominal incision just below the umbilicus. The GFN was transected proximally by dividing the nerve on been proposed to play an important role in inguinoscrotal ...

Objective To investigate the eCect of age on fertility and early adulthood. However, in late adulthood there was a significant reduction in pregnancy rate in females testicular development in rats with untreated unilateral undescended testes.coupled with cryptorchid rats compared with that of females coupled with control rats. There was a signifiMaterials and methods Newborn male Wistar King-A rats were divided into two groups. In group 1, a cant degeneration of the unilateral cryptorchid testes compared with control testes in both early and late mechanical model of unilateral undescended testis was created by performing extra-abdominal fixation of the adulthood. In contrast, there were no significant changes in histological development between the congubernaculum in the neonatal period, and in group 2, sham-operated rats were used as controls. At 90 tralateral scrotal testes and the controls in early adulthood, although they were significantly diCerent days old (early adulthood), the fertility of both groups was assessed by mating the rats with mature virgin from the controls in late adulthood. Conclusion These results suggest that fertility is aCected females for 2 weeks. Thereafter, some of the rats were killed and their testes examined histologically, while by ageing in untreated unilateral cryptorchidism; this may be induced by extensive damage not only in the the remaining rats were allowed to develop further. At the age of 180 days (late adulthood), fertility was undescended testes, but also in the contralateral scrotal testis, in this mechanically induced model of unilatre-assessed in the same way. All the rats were then killed and their testes removed for histological eral cryptorchidism.