Werness P G, Duckworth S C, Smith L H
Invest Urol. 1979 Nov;17(3):230-3.
Calcium oxalate dihydrate (COD), although thermodynamically unstable with respect to calcium oxalate monohydrate (COM), is more commonly seen in human urine. For the first time, a COD-seeded crystal growth assay has been developed. Seed crystals of COD were precipitated from filtered urine by the addition of ammonium oxalate and were stored dry and added to a supersaturated calcium oxalate solution to initiate an experiment. The growth rate in the COD-seeded system was 22 per cent of that for a COM-seeded system, for equivalent surface areas. Urine samples from normal subjects have similar inhibitory activity in the COD- and COM-seeded systems, as do pyrophosphate and heparin, which are known inhibitors of COM crystal growth. These results indicate that the technically simpler COM-seeded growth assay is suitable for measurement of inhibitors of calcium oxalate growth in urine.
二水合草酸钙（COD）虽然相对于一水合草酸钙（COM）在热力学上不稳定，但在人类尿液中更常见。首次开发了一种以COD为晶种的晶体生长试验。通过添加草酸铵从过滤后的尿液中沉淀出COD晶种，将其干燥保存并添加到过饱和草酸钙溶液中以启动实验。对于相同的表面积，以COD为晶种的系统中的生长速率是COM为晶种的系统的22%。正常受试者的尿液样本在以COD和COM为晶种的系统中具有相似的抑制活性，焦磷酸盐和肝素也是如此，它们是已知的COM晶体生长抑制剂。这些结果表明，技术上更简单的COM为晶种的生长试验适用于测量尿液中草酸钙生长的抑制剂。
