THE EFFECT OF PERITONEAL MACROPHAGE-DERIVED FACTOR(S) ON OVARIAN PROGESTERONE SECRETION AND LH RECEPTORS - THE ROLE OF CALCIUM

Macrophages and their secretory products, cytokines, play an integral role in many reproductive processes. In this study we examined the effect of conditioned media from cultured human peritoneal macrophages on progesterone production by granulosa cells and the role of calcium in this process. Macrophages were pretreated with various concentrations of a calcium channel blocker (verapamil) or a calcium ionophore (A23187). Macrophage-conditioned media (MCM) or cell-free media that contained calcium channel modifiers were added at three dose levels to cultured porcine granulosa cells. Progesterone production and LH receptor content were determined. Macrophage-conditioned media alone elevated basal progesterone production, but significantly attenuated granulosa cell LH receptor content. These effects were neither potentiated nor suppressed by pretreating macrophages with verapamil. However, production of the LH receptor lowering factor(s) appeared to be suppressed by calcium ionophore. We conclude that (1) one or more factors produced by macrophages have a net stimulatory effect on basal progesterone production and these factor(s) may not be calcium-dependent and (2) macrophage-derived secretory products reduce granulosa cell LH receptor content. The production of these factor(s) may be calcium-dependent.