Rat Ghrelin (aa 252-267) Synthetic Peptide. GHRL encodes ghrelin-obestatin preproprotein, which generates ghrelin and obestatin. Ghrelin is an the ligand for the growth hormone secretagogue receptor type 1 and is involved in regulating growth hormone release. Ghrelin has an appeptite-stimulating effect and induces adiposity and stimulates gastric acid secretion. Obestatin may be the ligand for the orphan G protein-coupled receptor GPR39 and is involved in satiety and can have an appetite-reducing effect resulting in decreased food intake.