Depressed DNA synthesis in vitro by early prepubertal undescended human testis.

To study the spermatogenic potential of the early prepubertal inguinal testis and the effect of temperature on spermatogenesis, the levels of incorporation of 3H-thymidine and 14C-uridine into the testicular tissue were studied at 31 degrees C and 37 degrees C in vitro and compared with those of scrotal (descended) testis. 3H-thymidine incorporation into the inguinal testicular tissue at 31 degrees C, which is close to normal testicular temperature, was significantly lower than that of the scrotal testis. There was no significant differences in 14C-uridine incorporation between inguinal and scrotal testis at that temperature. At 37 degrees C, which is close to normal body temperature, 3H-thymidine and 14C-uridine incorporation into the tissues of inguinal and scrotal testes was significantly higher than at 31 degrees C. It would appear that DNA synthesis of the inguinal testis is lower than that of the scrotal testis at 31 degrees C, and higher temperature, at least for a short while, did not contribute to the impairment of spermatogenic potential in early prepubertal inguinal testis.