Abnormal urate transport in erythrocytes of patients with idiopathic calcium nephrolithiasis: a possible link with hyperuricosuria.
1. The demonstration of an inheritable anomaly of erythrocyte oxalate transport in 'primary' calcium nephrolithiasis suggested that this disease might be a generalized metabolic disorder characterized by a defect in cellular anion transport. 2. To determine whether this anomaly is restricted to oxalate alone, we studied erythrocyte transmembrane urate self-exchange in calcium-oxalate renal stone formers in whom urinary excretion of uric acid is frequently increased. 3. Abnormal urate self-exchange was found in 30% of the patients. The urate self-exchange rate constant was correlated with 24 h urinary excretion of uric acid; the erythrocyte anomaly was also associated with the frequency of hyperuricosuria and a more intense disease activity. Transmembrane urate self-exchange was inhibited by stilbene and heparan sulphate. Morphazinamide administration did not reduce urinary urate excretion in patients with abnormal urate erythrocyte self-exchange. 4. These findings suggest that hyperuricosuria during calcium-oxalate renal stone disease might be due to a cellular defect in urate transport, and further support the hypothesis that idiopathic nephrolithiasis is a metabolic disorder characterized by a defect in cellular anion transport.
Gambaro
G
G
Institute of Internal Medicine, University of Padova, Italy.
Vincenti
M
M
Marchini
F
F
D'Angelo
A
A
Baggio
B
B
D001692:Biological Transport; D002129:Calcium Oxalate / Q000097:blood; D004910:Erythrocyte Membrane / Q000378:metabolism*; D006801:Humans; D007669:Kidney Calculi / Q000097:blood*; D014527:Uric Acid / Q000097:blood / Q000378:metabolism* / Q000652:urine
D002129:Calcium Oxalate; D014527:Uric Acid