Angayarkanni N, Selvam R
Department of Medical Biochemistry, Dr. ALM Post-Graduate Institute of Basic Medical Sciences, University of Madras, Taramani, India.
Nephron. 1999;81(3):342-6. doi: 10.1159/000045303.
The gamma-carboxy glutamic acid (gla) containing proteins have been shown recently to have a role in calcium oxalate urolithiasis. Therefore, the effect of carboxylation on calcium oxalate monohydrate (COM) binding was studied in experimental hyperoxaluria.
Urolithiasis was induced in experimental rats by oral feeding 1% ethylene glycol (EG). The microsomes were carboxylated in presence of reduced vitamin K and COM binding activity was determined.
Microsomal proteins adsorbed maximally with COM crystals. On carboxylation of the renal microsomal proteins, a significant increase in the COM crystal adsorption by 2.5-fold (p < 0.001) was observed in the hyperoxaluric condition. Further cyboxylated microsomes of EG-treated rats showed significant binding with calcium oxalate.
This study presents an increased COM adsorption after the carboxylation of renal microsomes of hyperoxaluric rats.
近期研究表明，含γ-羧基谷氨酸（gla）的蛋白质在草酸钙尿路结石形成中起作用。因此，本研究在实验性高草酸尿症中探讨了羧化作用对一水草酸钙（COM）结合的影响。
通过给实验大鼠口服1%乙二醇（EG）诱导尿路结石形成。在还原型维生素K存在的情况下使微粒体羧化，并测定COM结合活性。
微粒体蛋白与COM晶体的吸附达到最大量。在高草酸尿症状态下，对肾微粒体蛋白进行羧化后，观察到COM晶体吸附显著增加了2.5倍（p < 0.001）。此外，EG处理大鼠的进一步羧化微粒体显示出与草酸钙有显著结合。
本研究表明，高草酸尿症大鼠肾微粒体羧化后，COM吸附增加。
