Renal handling of uric acid in normal and gouty subject: evidence for a 4-component system.

Bidirectional renal urate tranport was studied in both control and gouty subjects. 99.3% of filtered urate undergoes reabsorption as assessed by pyrazinamide suppression of urate secretion. The maximum uricosuric response to benzbromarone, equated with the minimum secretory rate, amounted to 50% of the filtered load in normal persons and was lower in gouty normoproducers. Since benzbromarone selectively inhibits reabsorption of secreted urate, the difference between secreted and excreted uric acid becomes a valid measure of urate reabsorption distal to the secretory site and amounts to 80% of the secreted load in both groups. These data conform to a 4-component model of renal urate handling in man.