Some Effects of Chronic Gamma Irradiation on Mouse Testis

Abstract

Mice exposed to 12, 24, 43, and 74 r gamma radiation per day were observed with reference to the following parameters and compared with controls: testis weights, testis areas in section, tubular areas in section, Chalkley counts on cell types and on empty space within and surrounding the tubules, and srecial counts of type A and intermediate spermatogonia, type B spermatogonia, and leptotene spermatocytes. The results show that under prolonged gamma irradiation testis weights decrease concomitantly with the loss of spermatogenic cells from the tubules. Measurements of cross sectional areas of testes and tubules were found to decrease along with testis weight. There is an increase in the relative area occupied by the Sertoli cells surviving the gamma doses, because of decreasing tubular dimensions. Spermatogonia under 12 and 24 r/day survive with low levels of mitotic activity. At higher intensities they do not survive beyond 2000 r cumulated dose. Spermatocytes vanish due to lack of recruitment as well as through irradiation death. Their disappearance time is intensity-dependent, The same is true of spermatids and spermatozoa. (auth)