Ghrelin: new insights into female reproductive system-associated disorders and pregnancy.

Ghrelin is considered the endogenous ligand of growth hormone secretagogue receptor type 1a, and its modulatory actions have been demonstrated in a large array of endocrine and nonendocrine functions. According to recent studies, ghrelin seems to act at different levels of the reproductive system, exerting predominantly inhibitory effects on mammalian reproduction. It has been shown to influence the reproductive system by regulating hormone secretion from the brain and by acting directly on the gonads to affect tissue development and steroidogenesis. Thus, the endocrine network, which integrates energy balance and fertility, might involve ghrelin. Furthermore, ghrelin levels and actions have been assessed in various female reproductive system disorders. The findings could lead to a better understanding of the pathogenesis of these disorders and, possibly, to more beneficial therapeutic strategies.