Ghrelin in vitro modulates vasoactive factors in human umbilical vein endothelial cells.

Objective: To determine whether Ghrelin could affect prostaglandins (PGs) and nitric oxide synthesis in human umbilical vein endothelial cells (HUVEC). The effect of Ghrelin on endothelial cell proliferation was also evaluated.

Design: In vitro research report.

Setting: Third-level referral academic centers, including molecular and cellular biology laboratories.

Patient(s): Human umbilical cords were obtained from healthy female volunteers at term of uncomplicated pregnancies.

Intervention(s): HUVEC were cultured with Ghrelin (from 10(-11) to 10(-7) M). After 24 hours supernatants were collected and HUVEC were treated for total RNA extraction.

Main Outcome Measure(s): In the culture medium PGs release was evaluated by RIA. Prostaglandin-endoperoxide synthase 2 (COX2) and both the constitutive and the inducible isoforms of nitric oxide synthases (ECNOS and INOS) mRNA expressions were evaluated by retrotranscriptase polymerase chain reaction. Endothelial cell proliferation was evaluated by bromo-deoxy-uridine incorporation and by cell counting.

Result(s): Ghrelin negatively affected PGs release as well as COX2, ECNOS, and INOS mRNA expressions in HUVEC. Furthermore, Ghrelin increased bromo-deoxy-uridine incorporation in HUVEC without affecting cell counting.

Conclusion(s): Our in vitro results allowed to hypothesize that Ghrelin could be involved in the modulation of vascular tone by affecting nitric oxide-related protein synthesis and PGs production in endothelial cells.