[Proliferation and differentiation of regenerating Leydig cells following ethylene dimethane sulfonate exposure in rats].

Cell type of mammalian testis which is involved in the synthesis and secretion of testosterone and the maintenance of spermatogenesis are the fully differentiated interstitial Leydig cells (LC). Their ultrastructure possesses the typical characteristics of steroid-producing cells. It has been generally accepted that two waves of proliferation and differentiation can be discerned during the development of the Leydig cell population in the rodent and human testis. Treatment with ethane dimethane sulphonate (EDS) destroys selectively LC. A new LC population develops in the following weeks and this model has been used by us to study the proliferation and differentiation of new LC. Our results support the suggestion that the regeneration of a new LC population following EDS administration shows many similarities with the formation of the adult type LC in the prepubertal mammalian testis.