Phase-dependent influence of nonsteroidogenic cells on steroidogenesis andprostaglandin production by the human corpus luteum

Objective: To test the hypothesis that paraluteal cells in the human corpus luteum (CL) modulate steroidogenesis and prostaglandin production by the C L. Design: In vitro cell culture study using human luteal cells. Setting and Patient(s): Women (n = 7) with normal menstrual cycles who were undergoing operations for benign, nonovarian conditions during the midlute al phase (5-9 days after ovulation) or the late luteal phase (10-14 days af ter ovulation) at a university hospital. Intervention(s): Steroidogenic and nonsteroidogenic human CL cells were iso lated by mechanical and enzymatic digestion and density sedimentation. The cells were cultured (75,000 cells per well) for 24 hours either as a crude sample of all CL cells or as an enriched fraction of steroidogenic CL cells . Main Outcome Measure(s): Levels of progesterone, E-2 prostaglandins F-2 alp ha, E-2, and I-2 in conditioned medium. Result(s): Higher concentrations of progesterone, E-2, and prostaglandins F -2 alpha, E-2, and I-2 were released into the media of the crude sample of all CL cells than into the enriched fraction of steroidogenic CL cells from the midluteal phase. No such difference was noted in CL cells from the lat e luteal phase. Conclusion(s): The paraluteal cells in the human CL stimulated progesterone and E-2 synthesis. This may be mediated by an increase in prostaglandin pr oduction in the midluteal phase. (Fertil Steril(R) 2000;73:359-65. (C)2000 by American Society for Reproductive Medicine.).