Ghrelin Affects the Release of Luteolytic and Luteotropic Factors in Human Luteal Cells

Context: Ghrelin, well-known modulator of food intake and energy balance, is a rather ubiquitous peptide involved in several endocrine and nonendocrine actions. A possible as-yet-unknown role for ghrelin in modulating luteal function has been suggested because both ghrelin and its receptor (GRLN-R) have been immunohistochemically detected in human corpus luteum. Objective: We first investigated GRLN-R mRNA expression in midluteal phase human luteal cells. Ghrelin effect on basal and human chorionic gonadotropin (hCG)-stimulated progesterone (P) release was then analyzed. Finally, we investigated whether ghrelin could affect luteal release of vascular endothelial growth factor (VEGF), prostaglandin (PG) E2, both luteotropic factors, and PGF2α, luteolytic modulator. Ghrelin effect on both basal and hypoxia-stimulated VEGF luteal expression was analyzed. Methods: Human luteal cells were incubated for 24 h with ghrelin (10−13 to 10−7 m) or hCG (100 ng/ml) or CoCl2 (10 μm), chemical hypoxia, or with hCG or CoC...