Effect of salt loading on renal hemodynamics and electrolytes excretion in essential hypertension and in chronic glomerulonephritis.

Abstract

The salt loading test was performed in 7 normal aduls, 21 patiens With essential hypertension and 15 patients with chronic nephritis with and without hypertension. After an overnight fast, 5% saline solution was injected intravenously every 2 cc. per Kg. pf body weight and the changes in plasma electrolytes, renal hemodynamics, urine volume and urinary excretion of electrolytes were observed. The saline injection provoked the increase in plasma Na and Cl con-centrations, and the decrease in plasma K concentration was more prominent in the groups of essential hypertension and chronic nephritis with hypertension and it became greater with an increase in blood pressure. A linear relationship was observed between an increase in urinary excretion of Na and increase in glomerular fitration rate which were produced by the saline injection. In the patients with essential hypertension and with chronic hypertensive glomerulonephritis, the urinary excretion of Na after the saline injection became greater with an increase in blood pressure. The present experimental results seem to indicate that hypertension promotes a urinary excretion of Na, unless any remarkable decrease in renal blood flow and glomerular filtration rate exists.