Ионорегулирующая функция почек и эффект глюкагоноподобного пептида-1 у крыс на высокосолевой диете

Abstract

Glucagon-like peptide-1 (GLP-1) is the main incretin hormone that has an insulinotropic effect after a meal, as well as a physiologically significant natriuretic factor that contributes to the regulation of sodium and water balance. The aim of the work is to evaluate the effect of GLP-1 and its mimetic on the ion-regulating function of the kidneys in rats that are kept on a diet with a high concentration of NaCl for a long time, as well as in experimental hypervolemia and hypernatremia. In Wistar rats that received feed with a high content of NaCl (4%) for a month compared to animals on a standard diet (0.4% NaCl) the levels of blood pressure and atrial natriuretic peptide did not change, the aldosterone concentration in the blood decreased, the urinary excretion of sodium, calcium and chloride ions increased. After the administration of glucagon-like peptide-1 (GLP-1) and its mimetic, exenatide, the excretion of sodium ions and chlorides by the kidneys increased, the magnitude of natriuresis was equal in rats with different levels of NaCl intake with feed, that indicates the independence of the natriuretic action of GLP-1 from the excess of NaCl in the body due to the long-term high salt intake. In contrast to the standard diet, on high-salt feed, a lower level of aldosterone in the blood of rats caused a lower loss of potassium in the urine under the action of GLP-1 and exenatide. Similar changes in the urinary sodium and potassium excretion were observed under the action of GLP-1 mimetic in rats with hypervolemia caused by intraperitoneal administration of isotonic NaCl solution. A summation of the effects of exenatide and a loading test on the excretion of sodium was observed in rats with hypernatremia after administration of hypertonic solution of NaCl. Thus, GLP-1 is an effective natriuretic factor, both under standard conditions of water-salt balance, as well as with acute and chronic excess of NaCl in the body.