Accelerated purine nucleotide degradation by anaerobic but not by aerobic ergometer muscle exercise

The exact conditions under which exercise causes purine nucleotide degradation are not well understood. We determined plasma hypoxanthine and uric acid levels serially in eight individuals during ergometer muscle exercise. When the load was increased gradually by 15 W/min, plasma hypoxanthine was elevated only after the status exceeded the anaerobic threshold (AT), as determined by analysis of expired gas. Nonstrenuous ergometer exercise, which kept the status continuously below the AT, induced neither blood lactic acid nor plasma hypoxanthine elevation. These results suggest that the AT is also the threshold for the acceleration of purine nucleotide degradation. Muscle exercise to a degree that does not exceed the AT does not cause major purine nucleotide degradation, and, therefore, is expected to be beneficial for patients with gout and/or hyperuricemia.