Abstract
In order to more fully clarify the suppression of plasma renin activity (PRA) in essential hypertension with low PRA, PRA, plasma aldosterone, serum and urinary sodium, potassium and osmorality were measured in patients with low, normal and high PRA before and after the intravenous administration of furosemide (0.7mg/kg) and 2 hours of ambulation. Before the above test, patients with low PRA showed lower levels of hematocrit, significantly higher levels of serum sodium and serum osmorality than other two groups. After the above test, the same group showed lower blood pressure, more increased urinary volume, more decresed urinary sodium and potassium excretion, higher reabsorption of sodium, and lower reabsorption of free water than other groups. Therefore, it might be concluded that patients with low PRA have abnormalities in renal tubular sodium reabsorption and urinary concentration mechanism as a factor for the suppression of PAR, as compared with other two groups.
