Interaction of growth hormone and insulin-like growth factor-I in the control of steroidogenesis by cultured porcine granulosa cells

Abstract

In order to better understand the factors controlling or modulating ovarian function, and in an attempt to develop a way to increase ovulation rate in gilts, the effects of metabolic hormones such as growth hormone (GH), insulin or prolactin and growth factors such as insulin-like growth factor I or II (IGF-I or IGF-II) on steroidogenesis in cultured porcine granulosa cells were investigated with emphasis on the interaction between GH and IGFs. Experiment one was conducted to examine the influence of metabolic hormones and growth factors on progesterone and estradiol secretion by porcine granulosa cells in culture, and to determine the possible site(s) of action of these agents on steroidogenesis. Both IGF-I and IGF-II increased (P $