Response of the Sertoli cell and stem germ cell to 60Co γ radiation (dose and dose rate) in testes of immature rats

Abstract

The authors examined γ radiation effects (dose and dose rate) on the Sertoli cells and stem cells of the germinal line in immature rat testes. Prior to day 4 of postnatal development, the gonocyte or primitive germ cell was the most radiosensitive cell in the testis. From day 4 to approximately day 15 the Sertoli cell was the most critical element, and thereafter the stem cell was of first importance. A dose of 100 rads irreversibly reduced the number of Sertoli cells to 63% of control. Of the ages tested beyond Day 2, the 9 day testis was most severely affected. It was estimated that a dose of 400 rads would reduce sperm output of the 9 day testis to 21% of control. After day 4 and prior to Day 20, 300 rads produced a permanent decrement in the stem cell population. Six hundred rads are required to produce this effect in the adult. Dose rate was an important mediator of the radioresponse of both Sertoli and germ cells.