see also:

• insulin
• cholecystokinin (CCK)
• glucagon

• Ghrelin is a hormone released into circulation from the stomach and plays a key role in stimulating food intake by inhibiting vagal afferent firing.
• Circulating ghrelin levels are increased by fasting and fall after a meal.
• Central or peripheral administration of acylated ghrelin to rats acutely stimulates food intake and growth hormone release, and chronic administration causes weight gain. The action of ghrelin on feeding is abolished or attenuated in rats that have undergone vagotomy or treatment with capsaicin, a specific afferent neurotoxin.
• In humans, intravenous infusion or subcutaneous injection increases both feelings of hunger and food intake, since ghrelin suppresses insulin release, it is not surprising that secretion is disturbed in obesity and insulin resistance