IMPAIRMENT OF URIC ACID EXCRETION IN GOUT

The urinary excretion of uric acid in individuals with primary gout has been shown to be approxi-mately the same as, or in a minority of instances greater than, that of normal subjects on com-parable diets (2, 3). These observations, plus the failure to demonstrate significant differences in the renal clearance of uric acid in gouty and non-gouty control subjects, have led to the conclusion that patients with gout excrete uric acid in a nor-mal manner (2-5). This view has, however, recently been chal-lenged (6) on the ground that in the studies on which it was based, differences in the plasma urate concentrations of gouty and nongouty subjects were not taken into account. In order to elimi-nate such differences Nugent and Tyler (6) in-duced hyperuricemia in nongouty individuals by the oral administration of uric acid precursors and compared uric acid excretion in these subjects and patients with gout. Under these conditions an impairment in urate excretion was clearly evi-dent in patients with gout; both the excretion and clearance of urate were significantly less than in nongouty subjects with equivalent plasma urate levels. These observations of impaired uric acid excre-tion were fully supported by the present study, in which urate was administered intravenously to gouty and nongouty subjects in order to a) study urate excretion at equivalent and various plasma levels and b) examine the dynamics of the renal tubular transfer mechanisms for urate