Although a genetic predisposition to gout has been recognised for centuries, its mechanism has never been defined. This study was designed to determine whether this factor might be the renal clearance of urate, which is an important determinant of the concentration of urate in serum. In this study the renal clearance of urate was examined in 37 pairs of normouricaemic twins to determine whether...

1. The renal mechanism for urate excretion in the Dalmatian dog resembles that in birds. Urate is cleared at a rate considerably greater than the glomerular filtration rate, indicating that its excretion is the result of both glomerular filtration and active tubular secretion. The basic physiological mechanisms involved in the anomalous purine metabolism of the Dalmatian are indicated and their...

(1) Calcium greatly increased crystallization of monosodium urate in otherwise pure water, by enhancing both nucleation and growth. (2) Acid accelerated urate nucleation, both by its direct action and indirectly by increasing the free calcium in physiological fluids. (3) Synovial fluid from one gouty patient accelerated urate nucleation, while that from one rheumatoid patient inhibited nucleati...

The theory of the "four-component model" of urate excretion in humans is reevaluated, considering that a decrease in urate excretion induced by drugs like pyrazinamide or by endogenous compounds like lactate and ketone bodies might be a result of stimulation of urate reabsorption and not, as previously considered, of inhibition of urate secretion.

Inhibition of [14C]-urate uptake by uricosuric and antiuricosuric agents was investigated in human brush-border membrane vesicles, urate being transported either by anion exchange mechanisms or by voltage sensitive pathway. The IC50 for drugs on [14C]-urate uptake in vesicles loaded with 1 mM cold urate or with 5 mM lactate was, respectively: 0.7 and 0.3 microM for benzbromarone; 6 and 4 microM...

The urate concentration of the supernatant was greater after supersaturated solutions of sodium urate were incubated in a suspension of CM-Sephadex C-25 than in one of Sephadex G-25. The supernatant urate concentration was greater when the CM-Sephadex had been equilibrated with potassium than with sodium. The results are analogous with those obtained in studies of urate solubility in proteoglyc...

uricase or urate oxidase (urate:oxygen oxidoreductase, ec 1.7.3.3), a peroxisomal enzyme which is found in many bacteria, catalyzes the oxidative opening of the purine ring of urate to yield allantoin, carbon dioxide, and hydrogen peroxide. in this study, the phylogeny of urate oxidase (uricase) producing bacteria was studied based on gene sequences of 16s rrna and uricase protein. representati...

      Uricase or Urate oxidase (urate:oxygen oxidoreductase, EC 1.7.3.3), a peroxisomal enzyme which is found in many bacteria, catalyzes the oxidative opening of the purine ring of urate to yield allantoin, carbon dioxide, and hydrogen peroxide. In this study, the phylogeny of urate oxidase (uricase) producing bacteria was studied based on gene sequences of 16S rRNA and uricase protein. Repres...

Department of Pharmacology and Toxicology, Kyorin University School of Medicine, 6-20-2, Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan Corresponding author: Naohiko Anzai, M.D., Ph.D. Department of Pharmacology and Toxicology, Kyorin University School of Medicine, 6-20-2, Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan Tel. +81 4224 7551 1 ext. 3452 Fax. +81 4227 9132 1 E-mail: [email protected]...

The effect of various drugs on urate binding to plasma proteins was investigated in normal subjects. Whereas allopurinol, aspirin, phenylbutazone, probenecid, and sulphinpyrazone all significantly reduced plasma urate concentrations, only aspirin, phenylbutazone, and probenecid significantly impaired urate binding. Colchicine and indomethacin in the doses administered had no significant effect ...