THE EFFECT OF PHENYLBUTAZONE ON URIC ACID METABOLISM IN TWO NORMAL SUBJECTS

Abstract

Uric acid-N15 was given to 2 normal subjects on purine-free diets during control periods and again during phenylbutazone ingestion. From a comparison of the magnitudes of contracture of the miscible pools and the cumulative increments in urinary urate excretions, it was concluded that the uricosuric effect of phenylbutazone adequately explains the observed suppressions of serum urate concentration. The rates of urate biosynthesis did not change significantly during the periods of study. Also, extra-renal disposal and catabolistn of urates as measured by urinary recovery of N15 in uric acid decreased in both subjects. These changes were probably secondary to the marked reduction in serum urate concentrations. The uric acid space increased by about 15 l in both subjects, but this expansion explained only a small portion of the suppression of serum urate concentration. Hence phenylbutazone seems to have only one important effect on uric acid metabolism in normal subjects, viz., the enhancement of urinary urate excretion.