EFFECT OF ACTIVIN-A ON PROGESTERONE SYNTHESIS IN HUMAN LUTEAL CELLS

Objective: To examine the effect of activin-A on basal and hCG-stimula ted P production by human luteal cells. Design: Mixed luteal cell cult ures and distinct cultures of two luteal cell types: small and large l uteal cells from early and midluteal phase. Setting: Corpora lutea (CL ) were obtained from the Obstetrics and Gynecology Department of the C atholic University, Rome, Italy. Patients: Fifteen nonpregnant women b etween 30 and 45 years of age underwent surgery for nonendocrine gynec ological diseases. Interventions: Corpora lutea were obtained at the t ime of hysterectomy. The luteal cells were dispersed in Ham's F-12 med ium containing collagenase at 37 degrees C in shaking water bath for 2 hours, filtered, centrifuged, and resuspended in fresh medium. Main O utcome Measures: The cells diluted to a final concentration of 60,000 to 100,000 cells/ mt of medium. After 24 hours, the cells attached to the wells and were incubated with or without hCG and/or activin-A at d ifferent concentrations. Results: Activin-A starting from 25 mu g/L si gnificantly decreased basal and hCG (250 mIU/mL [conversion to SI unit , 1.00])-induced P production by mixed luteal cells. The small luteal cells responded to hCG (250 mIU/mL), and the treatment with activin-A (from 25 to 100 mu g/L) reduced their basal and hCG-induced P producti on. Activin-A addition did not change the amount of P release by large luteal cells at any concentration. Conclusions: These results imply t hat activin-A plays a role in the local regulation of human CL.