The Effect of Testicular X‐irradiation on Spermatogenesis in Man

Abstract

Existing data concerning the effects of x‐irradiation on spermatogenesis in man were analyzed and the results were compared to published data on the mouse. Testicular x‐irradiation produced a transient, but substantial, suppression of sperm counts in man, with an ED 50 near 11 rad. The length of time to recovery was proportional to the irradiation dose. The ED 50 for suppression of type A spermatogonia following radiation exposure in man was similar (9.7 rad), although the response curves for spermatogonia and sperm count were not parallel. The effect of irradiation on type A spermatogonia in the mouse was parallel to that found in man, but with an ED 50 of 30.0 rad. These results suggest that, compared to the mouse, spermatogenesis in man is approximately 3.1 times more sensitive to ionizing irradiation.