Inhibin production by macaque granulosa cells from pre- and periovulatory follicles: regulation by gonadotropins and prostaglandin E2.

Although inhibin (IN) is secreted by granulosa cells (GC) of preovulatory follicles, the major source of immunoreactive IN circulating during the primate ovarian cycle is the corpus luteum. The aims of this study were (1) to investigate culture conditions for optimal IN production by luteinized GC (LGC) from rhesus monkeys and (2) to compare IN and progesterone (P) production by nonluteinized GC (NGC) and LGC in response to putative agonists. Animals were treated for up to 9 days with human menopausal gonadotropins to promote the development of multiple preovulatory follicles. GC were obtained from large follicles before (NGC) or 27 h after (LGC) an ovulatory injection of hCG. For Aim 1, cells were cultured in Hams F-10 medium +/- hCG (100 ng/ml) with or without the addition of insulin/transferrin/selenium, 10% fetal bovine serum, or 10% Serum-Plus (JRH Biosciences, Lenexa, KS). Medium was changed on Days 1, 2, 4, 6, and 8, and IN and P concentrations were determined by RIA. Basal (unstimulated) IN production by LGC was enhanced and maintained for 6-8 days in the presence of serum, but rapidly declined in the absence of serum. In contrast, basal P secretion declined regardless of exposure to serum. Human CG consistently increased (p less than 0.05) IN production only in the presence of serum but stimulated (p less than 0.05) P production under all conditions. For Aim 2, cells were cultured for 4 days in Ham's F-10 medium + 10% macaque serum +/- hCG (100 ng/ml), hFSH (100 ng/ml), prostaglandin E2(PGE2; 14 microns), or dibutyryl(db)-cAMP (5 mM).(ABSTRACT TRUNCATED AT 250 WORDS)