草酸钙结石患者尿中蛋白结合型γ-羧基谷氨酸的检测意义

目的　探讨含γ 羧基谷氨酸 (Gla)蛋白质及其Gla残基在尿石形成中的作用。　方法　采用过饱和结晶法从新鲜尿液中提取草酸钙晶体基质 ,高效液相色谱法 (HPLC)测定 2 5例草酸钙结石患者尿液和提取的晶体基质中蛋白结合型Gla含量。　结果　草酸钙结石患者尿蛋白结合型Gla浓度为 (1.32± 0 .2 4)nmol/ml,2 4h尿含量为 (2 .0 4± 0 .6 5 ) μmol,显著低于正常人 ;草酸钙结石患者尿液提取的晶体基质中蛋白结合型Gla含量亦显著低于正常人。　结论　草酸钙结石患者尿液中蛋白结合型Gla含量较少 ,尿液含Gla蛋白质的羧基化程度低下可能是结石形成的重要原因之一。

Protein-bound gamma-carboxyglutamic acid in urine of calcium oxalate calculus formers

Objective To evaluate the role of Gla-bound protein and its Gla residue in urinary lithogenesis. Methods Calcium oxalate crystal matrix was produced by calcium oxalate supersaturation crystallization in fresh urine of normal subjects and calcium oxalate stone formers. Protein-bound Gla was determined in the crystal matrix and urine of normal subjects and in the calcium oxalate stone formers by high performance liquid chromatography. Results Protein-bound Gla in the crystal matrix and urine of calcium oxalate stone formers were significantly less than that of normal subjects. Conclusions Highly carboxylated Gla-bound proteins are inhibitory factors of calcium oxalate calculus. Insufficient carboxylation of urinary Gla-bound proteins may be correlated with urinary lithogenesis.