Renal Handling of Uric Acid

Abstract

Fifteen years ago Gutman and Yü summarized their views on the then rapidly developing subject of urate excretion in man (1). They proposed that urate was filtered at the glomerulus, reabsorbed by the renal tubule and also secreted by the renal tubule. Five major arguments were used in support of the suggestion that there was bidirectional transport of urate across the renal tubular epithelium. First, there existed demonstrations that in some species of animals there was net secretion of urate, while in others there was net reabsorption (1). It was conceivable that both processes could coexist in a single species one or the other being dominant. Second, they interpreted the “tubular titration curve” for urate in man as being consistent with bidirectional transport, patterning their argument after a more general treatment presented by others (2). Third, they had previously demonstrated net secretion of urate in humans with low filtration rates during treatment with an osmotic diuretic and uricosuric agents (3); normally there is net reabsorption of urate in the human. Fourth, there appeared to be an analogy between the renal mechanisms for urate and the bidirectional tubular transport of potassium (4) or certain foreign organic chemicals (2).