APOPTOSIS AND SPERMATOGENESIS - EVIDENCE FROM AN IN-VIVO MODEL OF TESTOSTERONE WITHDRAWAL IN THE ADULT-RAT

The seminiferous epithelium is a highly proliferating tissue in which germ cell ''degeneration'' is a constant feature. Recent data based on morphological analysis have shown that spontaneously dying germ cells display some characteristics of apoptosis. In order to evaluate the m olecular signals controlling the phenomenon, adult male rats were stud ied after in vivo treatment with ethane dimethane sulphonate, an agent which leads to testosterone withdrawal by a selective destruction of Leydig cells. DNA fragmentation by agarose gel electrophoresis and cel l DNA content by flow cytometry after propidium iodide staining were u sed to evaluate and quantify apoptosis in the testis. Despite the simu ltaneous presence of cells with different ploidies, the present data s uggest that testosterone withdrawal induces death by apoptosis and tha t this phenomenon is particularly evident in aploid germ cells. Thus, this study support the involvement of testosterone in regulating progr ammed cell death, beside cell proliferation and differentiation,during spermatogenesis. (C) 1994 Academic Press, Inc.