Exenatide injection to female Wistar rats induced an increase in diuresis, urinary sodium and mild potassium excretion. The maximum natriuretic effect of exenatide was 18500 times more pronounced compared to that of furosemide in equimolar dose. The natriuretic and diuretic effects after combined administration of maximum doses of exenatide and furosemide were additive, which was indicative of different mechanisms of their action on the nephron. Exenatide probably inhibits sodium reabsorption in renal proximal segment. The data obtained might be essential for assessment of the clinical use of exenatide to excrete extracellular fluid excess in cases of edemation and to maintain potassium balance.