How can one define urate overproduction in man?: 61

Abstract

Initial studies suggested that a patient suffered from urate overproduction if the urine urate exceeded 600 mg/24 hours on a low purine diet or if glycine incorporation into urinary urate exceeded 0.3% in seven days (Seegmiller, Wyngaarden). Subsequent studies in normal subjects suggested that urate production relates to body size and that some relativity to body weight or surface area needs to be incorporated into any definition of overproduction (Sorensen). The variation in the percentage of produced urate which was excreted by the renal route also needs to be considered in assessments involving the 24 hour urinary urate excretion. More recent studies have shown a wider range of urine urate in healthy subjects on a low purine diet (Emmerson). In addition, lower values for urine urate excretion were obtained with synthetic purine free diets than with diets containing food low in purines (Loeffler & Zollner). Our recent studies in lymphoblasts from patients with urine urate exceeding normal values by standard criteria have not demonstrated any increase in de novo purine biosynthesis. Although severe degrees of urate overproduction can be defined from measurements of urine urate, it now seems very difficult to establish minor degrees of urate overproduction by such measurements.