Tritium toxicity in mouse testes: effect of fractionated dose during post-natal development

A qualitative and quantitative study on the effect of fractionated doses of tritium on the testes of Swiss albino mice during post-natal development was undertaken. Examination of the testes at the end of the 6th week of post-natal life showed the following: the doses applied do not result in any major histopathological change except for a dose-dependent fibrosis in the tunica albuginea and hyperaemia. At a dose of 5.0 μCi a few pyknotic nuclei and necrotic cells and exfoliation of the germ cells also occurred; quantitative study revealed different variations in the germ cell population of the seminiferous epithelium. A dose of 1.25 μCi does not bring about any statistically significant variation in number of the different spermatogenic cells except for the decrease in pachytene in the populations of spermatocytes and spermatids; doses of 1.25 and 2.50 μCi, however, raised the spermatogonial population above the norm (statistically nonsignificant); primary spermatocytes showed a dose-dependent reduction in number; in all the groups, the number of spermatids was among all the seminal cell types the most reduced; a dose of 5.0 μCi produced the most significant signs of degeneration and necrosis in the testes of the experimental animals. (author)