Augmentation by epidermal growth factor of basal and stimulated progesterone production by human luteinized granulosa cells

Human granulosa cells were prepared from follicular aspirates obtained during oocyte collection for in vitro fertilization. Following several days in culture, cells were washed and then progesterone output was measured in 2-h incubations. After culture for 3 days, incubated cells responded well to human chorionic gonadotrophin (hCG) and prostaglandin (PG) E2 with similar levels of maximum response. Exposure of cultured cells to epidermal growth factor (EGF) for 2 days (days 3-5) led to substantial increases both in basal production and in responses to hCG and PGE2 during subsequent incubations. These effects of EGF were not accompanied by measurable increases in DNA levels in cultures over this time. Results may point to a possible paracrine role for EGF-like factors modulating the activity of cells forming the early corpus luteum.