Rodgers A L, Ball D, Harper W
Department of Chemistry, University of Cape Town, South Africa.
Scanning Microsc. 1994 Mar;8(1):71-7.
After filtration and ultrafiltration (10 kD) of 24 hour urine specimens from 12 healthy male subjects, calcium oxalate crystallization was induced in the filtered (FILTD) and ultrafiltered (UF) fractions by administration of a sodium oxalate load. In addition crystallization was also induced in UF fractions to which physiological quantities of chondroitin sulphate (CHON) had been added (UF+CHON). The rate of calcium oxalate crystallization was determined by measuring the rate at which turbidity increased. Crystal numbers and sizes were measured with a Malvern particle size analyzer and by scanning electron microscopy. Crystallization rates, crystal numbers and crystal sizes were generally lower in UF fractions than in FILTD fractions suggesting that urinary macromolecules are promoters of calcium oxalate crystallization. No increase in crystallization rate, crystal numbers or sizes occurred when chondroitin sulphate was added to UF fractions, indicating that the promoter activity of urinary macromolecules is not due to this particular glycosaminoglycan. On the contrary, crystallization rates were qualitatively lower in UF+CHON fractions than in UF fractions alone, suggesting a possible inhibitory role for chondroitin sulphate in real urine. Scanning electron microscopy revealed that while aggregates were present in UF and FILTD fractions, they were absent in UF+CHON fractions. This observation indicates that chondroitin sulphate might be an inhibitor of calcium oxalate crystal aggregation in real urine.
对12名健康男性受试者的24小时尿液样本进行过滤和超滤（10 kD）后，通过给予草酸钠负荷，在过滤后的（FILTD）和超滤后的（UF）组分中诱导草酸钙结晶。此外，在添加了生理量硫酸软骨素（CHON）的超滤组分（UF+CHON）中也诱导了结晶。通过测量浊度增加的速率来测定草酸钙结晶的速率。用马尔文粒度分析仪和扫描电子显微镜测量晶体数量和大小。超滤组分中的结晶速率、晶体数量和晶体大小通常低于过滤后组分，这表明尿液中的大分子是草酸钙结晶的促进剂。当向超滤组分中添加硫酸软骨素时，结晶速率、晶体数量或大小没有增加，这表明尿液大分子的促进活性不是由于这种特定的糖胺聚糖。相反，UF+CHON组分中的结晶速率在质量上低于单独的超滤组分，这表明硫酸软骨素在实际尿液中可能具有抑制作用。扫描电子显微镜显示，虽然在超滤和过滤后组分中存在聚集体，但在UF+CHON组分中不存在。这一观察结果表明，硫酸软骨素可能是实际尿液中草酸钙晶体聚集的抑制剂。
