Luteinizing hormone receptor appearance in cultured porcine granulosa cells requires continual presence of follicle-stimulating hormone.

Abstract

During the differentiation of ovarian granulosa cells, follicle-stimulating hormone (follitropin; FSH) mediates the induction of cell surface receptors for luteinizing hormone (lutropin; LH). Using primary cultures of porcine granulosa cells, we demonstrate that both the induction and maintenance of LH receptors are critically dependent upon the continual presence of FSH. The termination of FSH-promoted LH receptor induction is paralleled by the termination of FSH-induced intracellular cAMP accumulation. Changing the medium is without effect on FSH-induced appearance of LH receptors. Furthermore, 1 mM aminoglutethimide, which completely blocks FSH-stimulated progesterone biosynthesis, does not decrease the induction of LH receptors by FSH. Thus, the induction of LH receptors by FSH does not appear to require the accumulation of a factor in the medium, nor does it appear to be mediated via FSH-stimulated progesterone synthesis. These data suggest that intracellular cAMP, produced while FSH remains bound to the cell surface, mediates the induction of LH receptors and that the continual presence of FSH is required for both the induction and maintenance of cell surface LH receptors.