Figure 1. A simplified proposed model for ghrelin’s orexigenic action through AMP-AMPK in the VMH.
Fasting stimulates ghrelin production by endocrine cells of the stomach [21]. Ghrelin acts on GHSR on the VMH to phosphorylate AMPK. This results in a change in fatty acid biosynthesis (not shown), resulting in increased feeding.
GHSR: Growth hormone secretagogue receptor; VMH: Ventromedial nucleus of the hypothalamus; AMPK: 5' adenosine monophosphate-activated protein kinase; pAMPK: phosphorylated 5' adenosine monophosphate-activated protein kinase.