Localization of Irradiation Damage in Rat Seminiferous Tubules

Abstract

VISIBLE irradiation damage to the germ cells in mammalian gonads has been investigated extensively (review in ref. 1), but many questions about the dynamics of cellular turnover and the nature of barriers to recovery remain unanswered. Following certain radiation treatments, cross-sections of seminiferous tubules have been observed either to be spermatogenically inactive or to possess various degrees of spermatogenic activity². In testes of animals irradiated during foetal or early postnatal life, the lack of adjoining active and inactive tissue within a single seminiferous tubule might be a barrier to recovery. Germinal elements are unlikely to migrate through the rete testes from one tubule to another, and so an entirely atrophied tubule would be unlikely to recover, but active tissue might repopulate an adjacent inactive area. To determine whether single seminiferous tubules contain both active and inactive tissue, serial longitudinal sections of isolated fragments of seminiferous tubule were obtained and examined histologically.