We describe a male patient with four episodes of acute renal failure a
fter strenuous exercise occurring between the age of 14 and 25 years.
He was found to have low serum uric acid (0.4 mg dl(-1) after recovery
) and high fractional excretion of uric acid. A benzbromarone/pyrazina
mide test suggested that renal hypouricemia was due to defective proxi
mal tubular reabsorption of uric acid at a presecretory site. A renal
biopsy revealed acute tubular necrosis, a renal computer tomography sc
an showed patchy contrast enhancement and a treadmill exercise test in
duced an immediate fall in creatinine clearance. These findings sugges
t that the cause of acute renal failure was renal vasoconstriction rat
her than obstruction by uric acid crystals.