Showing papers by "Hospital Universitario La Paz published in 1985"
TL;DR: Results indicate that hypouricemia may provide an important clue for the existence of an underlying disease, and tubular urate transport defects may be of pathogenic importance in patients with recurrent calcium nephrolithiasis.
Abstract: Intrarenal handling of uric acid was evaluated in five patients with diminished serum urate levels (1.4 to 2.0 mg/dl) and increased renal clearance of uric acid (22.9 to 65.3 ml/min/1.73 m2). One patient with kappa light-chain disease and Fanconi syndrome showed a blunted uric acid excretion response to both pyrazinamide and probenecid, indicating a defective tubular reabsorption of urate. Three patients had recurrent calcium oxalate nephrolithiasis and one infant bening idiopathic hematuria. In addition to hyperuricosuria the infant and two patients with recurrent urolithiasis showed renal hypercalciuria. All evidenced normal responses to pyrazinamide. Compared to normal subjects, three patients showed a diminished and one an increased uricosuric response to probenecid. The former were considered to have a defective tubular urate postsecretory reabsorption and the latter an enhanced tubular secretion of urate. These results indicate that (1) hypouricemia may provide an important clue for the existence of an underlying disease, and (2) tubular urate transport defects may be of pathogenic importance in patients with recurrent calcium nephrolithiasis.
4 citations
TL;DR: The lower tubular urate postsecretory reabsorption of age-fertile women compared to men is in accordance with their lower serum urate concentration and higher fractinal excretion of uric acid, and plasma E2 does not influence renal handling of Uric acid.
Abstract: The lower serum urate concentration of age-fertile women compared to men is thought to be related to a higher renal clearance of urate possibly detrmined by plasma estrogen levels. We assessed renal handling of uric acid in 9 normal age-fertile women compared to 9 age-matched men. Women showed significantly lower serum urate concentrations than men (3.5 ± 0.3 vs. 4.9 ± 0.7 mg/dl, P < 0.001), higher fractional excretion of urate (9.8 ± 1.0 vs. 7.3 ± 0.8 percent, P < 0.001) and lower tubular urate postsecretory reabsorption (P <0.01). To test the hypothetical uricosuric effect of plasma E2 we administered estradiol valerate and estradiol benzoate to oophorectomized and age-fertile women, respectively. Plasma E2 levels and urinary total estrogen excretion increased significantly but failed to substantially modify serum urate or the fractional excretion of uric acid. Furthermore, in 4 normal age-fertile women tubular urate transport was not influenced by plasma E2 levels. The lower tubular urate postsecretory reabsorption of age-fertile women compared to men is in accordance with their lower serum urate concentration and higher fractinal excretion of uric acid. Plasma E2 does not influence renal handling of uric acid.
1 citations