title: Reduction of urinary uric acid excretion in patients with proteinuria.
abstract: Serum uric acid (UA) concentration is positively associated with proteinuria. However, the relationship between proteinuria and urinary metabolites of purine metabolism remains unknown. This study developed a hydrophilic interaction chromatography (HILIC)-based HPLC method with ultraviolet detection (UV) to quantify creatinine (Cr), UA, xanthine, and hypoxanthine in human urine simultaneously. The urinary concentrations of UA and Cr obtained by our method are consistent with those measured by an autoanalyzer. The HPLC-HILIC-UV method was validated as selective and robust with simple sample preparation for measuring UA, xanthine, hypoxanthine and Cr, which is suitable for large clinical studies. The UA/Cr ratios in random urine samples were 5.5 times lower in proteinuria patients (0.077±0.008) than in healthy individuals (0.424±0.037). Moreover, the UA/hypoxanthine ratio in proteinuria patients was approximately 10 times lower than that in healthy individuals. Our findings revealed a reduced urinary UA excretion, which is one of the factors leading to increased serum UA in proteinuria patients.
authors.affiliation: Jiangxi Provincial Key Laboratory of Molecular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, PR China; School of Pharmaceutical Science, Nanchang University, Nanchang 330006, PR China.
authors.forename: Huiqing
authors.initials: H
authors.lastname: Zou
authors.affiliation: Jiangxi Provincial Key Laboratory of Molecular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, PR China.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Xiang
authors.affiliation: Hospital of Nanchang University, Nanchang 330006, PR China.
authors.forename: Xinming
authors.initials: X
authors.lastname: Ye
authors.affiliation: School of Pharmaceutical Science, Nanchang University, Nanchang 330006, PR China.
authors.forename: Yuanzhen
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Jiangxi Provincial Key Laboratory of Molecular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, PR China; School of Pharmaceutical Science, Nanchang University, Nanchang 330006, PR China. Electronic address: xiebaogang@ncu.edu.cn.
authors.forename: Baogang
authors.initials: B
authors.lastname: Xie
authors.affiliation: Jiangxi Provincial Key Laboratory of Molecular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, PR China. Electronic address: shao5022@163.com.
authors.forename: Jianghua
authors.initials: J
authors.lastname: Shao
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D019271:Hypoxanthine / Q000652:urine; D057230:Limit of Detection; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000652:urine*; D015203:Reproducibility of Results; D014527:Uric Acid / Q000652:urine*; D019820:Xanthine / Q000652:urine; D055815:Young Adult
chemical_list: D019820:Xanthine; D014527:Uric Acid; D019271:Hypoxanthine; D003404:Creatinine
keywords: HPLC-HILIC-UV; Hypoxanthine and creatinine; Proteinuria; Uric acid; Xanthine