Substrate specificity of urate transporter in rat renal brush border membranes.
To further demonstrate the substrate specificity of urate-anion exchanger in rat renal brush border membrane vesicles, the hydroxyl ion gradient-dependent [2-14C] urate uptake was studied by a rapid filtration technique. The [2-14C] urate uptake was more sensitive to unlabeled urate than to unlabeled xanthine and hypoxanthine. In addition, urate derivatives which are methylated at the positions 3 and 9 hardly inhibited the urate uptake. Because of the substrate specificity, the urate-anion exchanger in brush border membranes appears to selectively use urate as the endogenous substrate.
Dan
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Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., Shizuoka, Japan.
Koga
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D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000493:pharmacokinetics*; D002462:Cell Membrane / Q000378:metabolism; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000493:pharmacokinetics; D007672:Kidney Cortex / Q000378:metabolism*; D008297:Male; D008871:Microvilli / Q000378:metabolism*; D051381:Rats; D013329:Structure-Activity Relationship; D013379:Substrate Specificity / Q000187:drug effects; D014527:Uric Acid / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics*; D019820:Xanthine; D014970:Xanthines / Q000493:pharmacokinetics
D002352:Carrier Proteins; D007042:Hypoxanthines; D014970:Xanthines; D019820:Xanthine; D014527:Uric Acid; D019271:Hypoxanthine