Effects of dietary sodium intake on blood pressure and urinary excretion of prostaglandins in normotensive and hypertensive subjects

Abstract

Blood pressure and the urinary excretion of prostaglandins (PG) E 2 and F 2α were evaluated in all female normotensive (NS), borderline hypertensive (BHS) and sustained essential hypertensive (EHS) subjects receiving diuretic treatment under normal and reduced dietary sodium intake. Plasma cholesterol, sodium, and potassium, and urinary sodium, potassium and creatinine were also assessed. As dietary sodium intake decreased, a decrease in blood pressure, an increase in urinary excretion of PGE 2 were observed in NS and BHS. Urinary PGF 2α excretion was increased in NS with dietary sodium restriction. There was no correlation between urinary sodium excretion and urinary excretion of PGE 2, PGF 2α or the ratio of PGE 2/PGF 2α. With normal sodium intake, urinary PGE 2 excretion was greater in NS as compared to BHS whereas with reduced dietary sodium intake, PGF 2α excretion was greater in NS than in EHS. Plasma cholesterol was decreased in NS and BHS during the sodium restriction period with the reduction occurring in very low density and low density lipoprotein fractions. The results of this study do not support a natriuretic role of renal PGE 2 but does support the hypothesis of decreased renal PGE 2 synthesis in hypertensive subjects.