Immunohistochemical detection of transforming growth factor-alpha in Leydig cells during the development of the rat testis.

In this paper the localization of transforming growth factor alpha (TGF-alpha) is described in the rat testis at various stages throughout development, e.g. neonatal, prepubertal, and adult, in order to examine somatic cells and germinal cells at different stages of differentiation. This was done by immunoperoxidase staining using a monoclonal antibody that does not cross-react with epidermal growth factor (EGF). In sections of testes from neonatal rats, intense staining was present in Leydig cells. In the cells of the seminiferous tubules the staining was faint or undetectable. At the time when many mesenchymal cells differentiate into Leydig cells in the 21-day-old rat, TGF-alpha was visualized in most but not all of the identifiable Leydig cells. In interstitial cell cultures derived from 21-day-old rats, the majority of the Leydig cells contained TGF-alpha, but in a proportion of the Leydig cells TGF-alpha was undetectable. No staining was apparent in Sertoli cells and germ cells in seminiferous tubules or in Sertoli cell cultures derived from 21-day-old rats. Under these in vitro conditions it was found that peritubular-myoid cells also possessed TGF-alpha immunoreactivity. In the adult testis all Leydig cells stained positively for TFG-alpha, whereas no staining was found in the cells of the seminiferous tubules. Treatment of adult rats with ethylene-1,2-dimethane-sulfonate (EDS) resulted in the destruction of Leydig cells and the loss of all positively stained for TGF-alpha.(ABSTRACT TRUNCATED AT 250 WORDS)