SPECIFIC IMMUNONEUTRALIZATION OF FSH LEADS TO APOPTOTIC CELL-DEATH OFTHE PACHYTENE SPERMATOCYTES AND SPERMATOGONIAL CELLS IN THE RAT

Although requirement for follicle stimulating hormone (FSH) in the ini tiation of spermatogenesis is well documented, its role in adult sperm atogenesis is still debated. In the present communication, we have inv estigated the effect of specific immunoneutralization of FSH on apopto tic cell death in the testicular germ cells both in immature and adult rats. The germ cells of control animals showed predominantly high mol ecular weight DNA while the antiserum (a/s) treated group showed DNA f ragmentation characteristic of apoptosis. The pattern could be detecte d within 24 hours of a/s treatment, and became more pronounced after 4 8 hours. The germ cells were purified from FSH a/s treated rats by cen trifugal elutriation and vulnerability of each cell type to undergo ap optosis on FSH neutralization was investigated. The pachytene spermato cytes were found to be most sensitive to absence of FSH, even in the a dult animals suggesting the involvement of FSH in spermatogenesis. The in situ analysis of DNA strand breakage following FSH a/s treatment s howed fragmentation of the DNA of the pachytene spermatocytes confirmi ng this observation. The in situ analysis also showed that the spermat ogonia undergo apoptosis in addition to the pachytene spermatocytes. T hese data clearly demonstrate the role of FSH in the adult rat spermat ogenesis.