Effects of interleukin-8 on estradiol and progesterone production by bovine granulosa cells from large follicles and progesterone production by luteinizing granulosa cells in culture

► IL-8 is included in follicular fluid in bovine ovary, and was high level as follicles grew. ► The signal transduction of IL-8 in granulosa cells may mainly mediate CXCR1 during late follicle development. ► IL-8 regulated steroid production in gonadotropin-treated granulosa cells in culture. ► IL-8 may act as a regulator of steroid synthesis in granulosa cells to promote luteinization after ovulation.