[Leptin and the kidneys. Review article].

Leptin is a protein hormone produced by adipocytes. Its basic known function is its central hypothalamic action leading to reduction of food intake and augmentation of energy expenditure and thus to reduction of body weight. Various types of leptin receptors were found in other organs and tissues. The kidney is the main site, where leptin is eliminated from the body (probably by tubular degradation) under normal conditions and its blood concentrations increase significantly during renal failure. Leptin increases diuresis and natriuresis, increases sympathetic nerve activity in the kidney and participates in the elevation of blood pressure. It can also be involved in morphological changes in renal tissue, such as glomerulosclerosis, or stimulate growth and invasiveness of tumours.