الفهرس 
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Abstract
Ghrelin is a 28-amino acid peptide produced predominantly by X/A-like cells of the mucosal layer in the fundus of the stomach. It is a key regulator of nutrient sensing, meal initiation, and appetite. Ghrelin signaling has increasingly been recognized as a key regulator of obesity, insulin resistance and diabetes; intriguingly, many of these regulatory functions appear to be independent of ghrelin’s effect on food intake. It has also been proposed to be involved in the control of the reproductive function.
Ghrelin‟s role in reproduction was first suggested by its wide expression in many human reproductive tissues including its immunohistochemical expression in the human ovary. Ghrelin expression is identified in the seminiferous tubuli of the interstitial Leyding and Sertoli cells in male testicles, whereas it is identified in the ovarian hilus interstitial cells and mature corpus lutea in females.
It is postulated that ghrelin plays a local regulatory role in the male and female gonads. In females, Ghrelin acts centrally by suppressing hypothalamic GnRH release and GnRH-induced gonadotropin secretion by the pituitary; and in gonads it acts by increasing luteolytic factors such as PGF2 alfa, and ghrelin inhibiting estradiol and progesterone biosynthesis in granulose-lutein cells as well as granulosa cell (GC) proliferation.