Влияние глюкагоноподобных пептидов и оксинтомодулина на экскрецию ионов натрия почками у крыс

Abstract

Maintaining sodium balance is ensured by a clear correspondence of salt intake through the gastrointestinal tract and its excretion mainly by the kidneys. It is of interest to evaluate the functional relationship of the digestive system and the kidneys and its contribution to maintaining a constant sodium concentration in the internal environment of the body. The aim of the study was to evaluate the participation of gut regulatory peptides, proglucagon derivatives, in the regulation of urinary sodium excretion. The diuretic and natriuretic effects of the intraperitoneal administration of oxyntomodulin, glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) at a dose of 1.5 nmol/kg were studied under normal and standardized (drink with 0.9% solution NaCl in a volume of 50 ml/kg) conditions of water-salt balance. An increase in urination and sodium excretion under the action of GLP-1 and a decrease in diuresis and natriuresis after injection of GLP-2 were shown. The effect of oxyntomodulin on kidney function has not been identified. The secretory response of the studied peptides to the load with oral administration of a 2.5% NaCl solution causing hypernatremia was evaluated: after 5 min an increase in GLP-1 concentration and a decrease in GLP-2 in the blood were observed, the level of oxyntomodulin did not change. The effect of peptides on the excretion of excess sodium and chloride by the kidneys during hypernatremia after oral and intraperitoneal administration of 2.5% NaCl solution (18 ml/kg) was studied. Injection of GLP-1 increased diuresis, excretion of sodium and chloride by the kidneys with an intraperitoneal NaCl load and accelerated the elimination of ions after oral loading. The antidiuretic and antinatriuretic effects of GLP-2 were revealed upon administration of the hormone with an oral NaCl load. Thus, derivatives of proglucagon, GLP-1 and GLP-2, are involved in the regulation of sodium balance. With an excessive intake of NaCl through the gastrointestinal tract, both the change of secretion of these regulatory peptides and their effects on urinary sodium excretion are oppositely directed.