We studied the effects of muscular exertion on uric acid metabolism in a patient with type VII glycogenosis (muscle phosphofructokinase deficiency), who had hyperuricemia.
Atter mild leg exercise on a bicycle ergometer, plasma inosine and hypoxanthine concentrations increased greatly, as did the plasma uric acid concentration, which showed a delayed response. Urinary excretion of uric acid did not decreased during exercise, but increased during the post-exercise period.
When the patient came to our clinic, the plasma hypoxanthine and uric acid concentrations were markedly elevated. By bed rest, plasma hypoxanthine level was normalized in a short time, and the plasma uric acid level decreased gradually but markedly within two days. In the same manner, urinary excretion of these metabolites was reduced by bed rest.
These findings indicate that large amounts of inosine and hypoxanthine are released from exercising muscle into circulating blood in patients with type VII glycogenosis, and thus hyperuricemia may develop due to overproduction of uric acid.
