The Anti-Edematous Effect of Ghrelin in Brain Hypoxia is Associated with Decreasing Expression of Vascular Endothelial Growth Factor.

There is increasing evidence that vascular endothelial growth factor (VEGF) has a role in the development of vascular leakage in the hypoxic brain. Our recent work showed an anti-edematous effect of ghrelin on brain hypoxia. However, the underlying mechanisms by which ghrelin exerts its anti-edematous effect are still unclear. For this purpose, we examined the effects of ghrelin on VEGF expression in the hypoxic brain. Adult male Wistar rats were divided into acute or chronic controls, acute or chronic hypoxia, and ghrelin-treated acute or chronic hypoxia groups. Systemic hypoxia was induced in rats by a hypoxic chamber (O2 10-11 %) for 2 days (acute) or 10 days (chronic). Effects of ghrelin on VEGF expression were evaluated using immunoblotting. Our data revealed that acute and chronic hypoxia increased VEGF expression in both acute and chronic hypoxia (P < 0.001). Ghrelin significantly reduced this expression in hypoxic conditions (P < 0.001). Our findings demonstrated the beneficial effects of ghrelin might be mediated, at least in part, through a decline in VEGF production.