THE EFFECT OF ACTIVIN AND FSH ON THE DIFFERENTIATION OF RAT GRANULOSA-CELLS

The differentiation of granulosa cells is regulated by follicle-stimul ating hormone (FSH) and local ovarian factors. To further analyze the role of FSH and activin in this process, we have examined the effect c l of FSH and activin on TSH and luteinizing hormone/human chorionic go nadotropin (LH/hCG) receptor induction in granulosa cells. Granulosa c ells from diethylstilbestrol (DES)-primed immature rats produce activi n and maintain FSH receptor without LH/hCG receptor expression in the absence iol FSH. On thr other hand, FSH induced granulosa cells to dif ferentiate into more mature granulosa cells in which higher LH/hCG rec eptor expression and diminished activin production were observed. (C) 1998 Federation of European Biochemical Societies.