[Uric acid and arterial hypertension. II. Evaluation of uric acid transport in the nephrons in primary arterial hypertension].

In forty patients with mild to moderate essential hypertension correlation between serum uric acid as well as renal excretion of urate and the transport of uric acid in nephron was evaluated. Quantity of the separate phases of uric acid transport in nephron was calculated based upon pharmacological tests with pyrazinamide and benzbromarone. The results obtained in twenty normotensive subjects were assumed to be a normal values. Positive correlation between serum uric acid and presecretory reabsorption of urate was found in hypertensive patients. However presecretory reabsorption of urate did not significantly differ between hypertensive patients with concomitant hyperuricemia and normotensive subjects. Tubular secretion of uric acid was significantly lower in hypertensive patients in comparison with normotensive subjects. Plasma uric acid correlated inversely++ with tubular secretion of urate in patients with essential hypertension. There was no difference in postsecretory reabsorption of uric acid between the groups. Plasma uric acid did not correlate with postsecretory reabsorption of urate in hypertensive patients. These findings suggest that decreased uric acid clearance in hypertension with concomitant hyperuricemia is connected with impaired tubular secretion of urate.