[Ghrelin--The guardian of energy balance]

Ghrelin was discovered in 1999 and is a subject of various studies. This endogenous ligand for the growth hormone secretagogue receptor (GHS-R) is mostly released by the fundus mucosa in the stomach. Many studies show us, that besides its stimulation of Gh secretion, ghrelin is directly related to the energy balance controlling mechanism. It also influences motoric action of the digestive track, secretion of hydrochloric acid, endo- and exogenic pancreatic function. GHR-S receptors are found in arcuate neurons and other lateral hypothalamus neurons. These areas are critical for the regulation of feeding. Ghrelin stimulates food intake together with other orexy- and anorexygenic peptides like: NPY, AGRP, OXA, and OXB. The plasma ghrelin level depends on the nutrition state. Increased ghrelin levels are observed shortly before food intake, and the decreases can be noted 2 hours after eating. During fasting and/or malnutrition plasma ghrelin level rises. This also happens in eating disorders: anorexia nervosa, bulimia nervosa. This article presents facts and hypotheses supporting the neuroendocrinologic and metabolic mechanisms affecting the plasma ghrelin levels and the role of ghrelin in feeding behaviour.