Effect of epidermal growth factor on steroidogenesis by caprine granulosa cells in culture: interaction with FSH

Besides gonadotrophins various peptide growth factors have been implicated in the ovarian folliculogenesis. In this study, the effect of epidermal gro wth factor (EGF) (0, 0.1, 1.0, 10 ng/ml culture medium) on steroidogenesis by caprine granulosa cells at various stages of maturation was investigated using serum free culture medium. Caprine granulosa cells were obtained fro m ovarian follicles and classified into three classes: small (<3 mm), mediu m (3-6 mm) and large (>6 mm in diameter). EGF (10 ng/m culture medium) alon e reduced estradiol secretion in granulosa cell from small, medium and larg e follicles by 62, 48 and 29%, respectively, as compared with control. This inhibition was 50, 36 and 21%, respectively, when EGF (10 ng/ml culture me dium) was applied in combination with FSH (100 ng/ml culture medium). EGF a lone stimulated the secretion of progesterone in granulosa cells from all t he three categories of follicles only at highest dose tested (10 ng/ml cult ure medium). FSH acted synergistically with EGF in stimulating progesterone secretion by cultured granulosa cells. EGF in combination with FSH (100 ng /ml culture medium) significantly (P <0.05) stimulated progesterone secreti on by cultured granulosa cells from all three categories of follicles even at the lowest dose (0.1 ng/ml culture medium) tested. In conclusion, EGF si gnificantly influences the steroidogenesis by caprine granulosa cells in vi tro and may play important role in the follicular growth and maturation. (C ) 2001 Elsevier Science B.V. All rights reserved.