Worcester E M, Nakagawa Y, Coe F L
Miner Electrolyte Metab. 1987;13(4):267-72.
Urine is normally supersaturated with respect to calcium oxalate. Inhibitors of the growth and aggregation of calcium oxalate crystals are present in urine and probably protect against calcium stone formation. These inhibitors are deficient in stone formers. The major inhibitor of calcium oxalate crystal growth is a non-dialyzable, anionic macromolecule. An acidic glycoprotein has been isolated from urine and human kidney tissue culture medium which inhibits calcium oxalate crystal growth in vitro. This glycoprotein crystallization inhibitor has a molecular weight of 14,000 daltons and contains 2-3 residues of gamma-carboxyglutamic acid. The dissociation constant for the calcium oxalate crystal-inhibitor complex is about 10(-7) M. The glycoprotein isolated from the urine of calcium stone formers has a decreased affinity for crystal surface, and a proportionally weaker inhibitory activity; it also lacks gamma-carboxyglutamic acid.
正常情况下，尿液相对于草酸钙处于过饱和状态。尿液中存在草酸钙晶体生长和聚集的抑制剂，可能对预防钙结石形成起到保护作用。这些抑制剂在结石形成者体内缺乏。草酸钙晶体生长的主要抑制剂是一种不可透析的阴离子大分子。已从尿液和人肾组织培养基中分离出一种酸性糖蛋白，它在体外可抑制草酸钙晶体生长。这种糖蛋白结晶抑制剂的分子量为14,000道尔顿，含有2 - 3个γ-羧基谷氨酸残基。草酸钙晶体 - 抑制剂复合物的解离常数约为10^(-7) M。从钙结石形成者尿液中分离出的糖蛋白对晶体表面的亲和力降低，抑制活性也相应减弱；它还缺乏γ-羧基谷氨酸。
