Figure 3. The relationships among insulin, leptin, pituitary gonadotropins, and ovarian steroidogenesis. Insulin stimulates leptin secretion, enhances pituitary gonadotropin response to GnRH, and promotes ovarian steroidogenesis. Leptin stimulates the hypothalamic-pituitary-gonadal axis at the level of the hypothalamus and/or pituitary; it inhibits ovarian E₂ and P production, but may stimulate androgen production by stimulating 17α-hydroxylase activity or expression. Leptin and insulin potentiate each other’s secretion, although leptin may inhibit insulin secretion under some circumstances. Ovarian sex steroids inhibit FSH production and either inhibit (E₂, T, P) or stimulate (E₁) LH responsiveness to GnRH.

Source: Endocr Rev 1999 Aug;20(4):535-82

Print this page

Edited by Aldo Campana,