EFFECTS OF FOLLICLE-STIMULATING-HORMONE ON INTERMEDIATE FILAMENTS ANDCELL-DIVISION OF SERTOLI CELLS OF FETAL-RAT TESTIS IN CULTURE

The present study was aimed to examine the effects of follicle-stimula ting hormone (FSH) on cell division of Sertoli cells from rat fetal te stes and on the kinetics of 2 kinds of intermediate filaments, cytoker atin and vimentin, which comprise the cytoskeleton of Sertoli cells. T estes from rat fetuses of different ages (from day 15 to day 17 of ges tation) were cultured for 48 hr, with or without added FSH. In 15-day testes, FSH influenced neither cell division of Sertoli cells nor kine tics of intermediate filaments. In 16-day testes, FSH promoted cell di vision of Sertoli cells and kinetic differentiation of intermediate fi laments distributed toward the lumen of the seminiferous tubules. Thes e 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 in termediate filaments increase in number and change in intracellular di stribution. It is concluded that FSH influences both proliferation and morphological differentiation of Sertoli cells.