Effects of follicle-stimulating hormone on intermediate filaments and cell division of Sertoli cells of fetal rat testis in culture

The present study was aimed to examine the effects of follicle-stimulating hormone (FSH) on cell division of Sertoli cells from rat fetal testes and on the kinetics of 2 kinds of intermediate filaments, cytokeratin and vimentin, which comprise the cytoskeleton of Sertoli cells. Testes from rat fetuses of different ages (from day 15 to day 17 of gestation) were cultured for 48 hr, with or without added FSH. In 15-day testes, FSH influenced neither cell division of Sertoli cells nor kinetics of intermediate filaments. In 16-day testes, FSH promoted cell division of Sertoli cells and kinetic differentiation of intermediate filaments distributed toward the lumen of the seminiferous tubules. These findings suggest that 16-day testes in culture can respond to FSH in a fashion that cell division of Sertoli cells is promoted and that intermediate filaments increase in number and change in intracellular distribution. It is concluded that FSH influences both proliferation and morphological differentiation of Sertoli cells.