0886-1714/99 5.00 © 1999 Int. Union Physiol. Sci./Am.Physiol. Soc. 80 The renal urate handling in humans has been explained for many years by a “four-component model.” The purpose of this review is to reevaluate the validity of the theory behind this hypothetical model in the light of the transport mechanisms that were characterized recently in the apical membrane (brush-border membrane; BBM) o...

BACKGROUND AND PURPOSE Serum urate concentration is associated with cardiovascular disease, and hyperuricemia predicts first-ever stroke. We explored the association of admission urate level with mortality, placement, and risk of further vascular events after acute stroke. METHODS In patients with ischemic stroke or primary intracranial hemorrhage, we determined the association of urate level...

GLUT9 (SLC2A9) is a newly described urate transporter whose function, characteristics, and localization have just started to be elucidated. Some transport properties of human GLUT9 have been studied in the Xenopus laevis oocyte expression system, but the type of transport (uniport, coupled transport system, stoichiometry ... .) is still largely unknown. We used the same experimental system to c...

Excretion of uric acid, a compound of considerable medical importance, is largely determined by the balance between renal secretion and reabsorption. The latter process has been suggested to be principally mediated by urate transporter 1 (URAT1; slc22a12), but the role of various putative urate transporters has been much debated. We have characterized urate handling in mice null for RST, the mu...

Compoundswhich interfere in the analytic determination of uric acid are referred to as “non-urate chromogens.”Ascorbic acid, when added to serum, causes a significant increase in apparent uric acid levels as determined by a carbonate-phosphotungstate method. The ratio of apparent urate to ascorbicacid is 1:3, a value in close agreement with that obtained for the ratio of labile non-urate chromo...

Elevated plasma urate levels are associated with metabolic, cardiovascular, and renal diseases. Urate may also form crystals, which can be deposited in joints causing gout and in kidney tubules inducing nephrolithiasis. In mice, plasma urate levels are controlled by hepatic breakdown, as well as, by incompletely understood renal processes of reabsorption and secretion. Here, we investigated the...

The inflammatory response to intraarticular urate crystals is known to be variable in gouty arthritis. One source of variability may be the modulation of cellular responses by crystal-bound proteins. We have identified three apolipoproteins among the polypeptides bound to urate crystals exposed to plasma. Identification was first based on their coelectrophoresis with polypeptides from isolated ...

BACKGROUND Increasing evidence suggests that urate may play an important role in neurodegenerative disease. In Parkinson's disease (PD) higher, but still normal, levels of blood and cerebrospinal fluid urate have been associated with a lower rate of disease progression. OBJECTIVE We explored the hypothesis that lower levels of urate and its purine precursors in brain may be associated with PD...

Uric acid, generated from the metabolism of purines, has both proven and emerging roles in human disease. Serum uric acid in humans is determined by production and by the net balance of reabsorption and secretion in kidney and intestine. In the human kidney, epithelial reabsorption dominates over secretion, such that in normal subjects there is at least 90% net reabsorption of filtered urate re...

When the level of uric acid, primarily in the form of monosodium urate (Wilcox, Khalaf, Weinberger, Kippen, and Klinenberg, 1972), exceeds the point of maximum solubility, crystals of monosodium urate may then form, particularly in the joints and connective tissues. These crystals initiate attacks of acute gout (Buchanan, Klinenberg, and Seegmiller, 1965; Seegmiller, 1965; Weissmann, 1971), and...