Shum D K, Liong E
Department of Biochemistry, Faculty of Medicine, University of Hong Kong.
Urol Res. 1995;23(2):103-10. doi: 10.1007/BF00307940.
To study the influence of renal polyanions on crystallization of urinary calcium oxalate, we recovered polyanionic macromolecules from media conditioned by primary cultures of renal proximal tubular epithelial cells of rats in serum-free, hormonally defined medium. Cells cultured on microporous supports showed a higher degree of morphological and functional proximal differentiation into a polarized monolayer than those on plastic impervious substrata. Papainization of the polyanions yielded the glycosaminoglycans chondroitin/dermatan sulphate and heparan sulphate. These accounted respectively for 60% and 80% of the crystal nucleation-promoting activities of polyanions recovered from the apical and basal media conditioned by polarized cultures on microporous supports. Similar relative activities were observed among the urinary glycosaminoglycans and polyanions similarly tested. Primary cultures of polarized proximal tubular epithelial cells are useful then as an in vitro model to study the crystallizing activities of polyanionic macromolecules produced by renal cells.
为研究肾多阴离子对草酸钙结晶的影响，我们在无血清、激素限定培养基中，从大鼠肾近端小管上皮细胞原代培养条件培养基中回收了多阴离子大分子。在微孔支持物上培养的细胞比在不透塑料的基质上培养的细胞表现出更高程度的形态和功能近端分化，形成极化单层。多阴离子经木瓜蛋白酶处理后产生糖胺聚糖硫酸软骨素/硫酸皮肤素和硫酸乙酰肝素。这些分别占从微孔支持物上极化培养条件培养基的顶端和基底培养基中回收的多阴离子晶体成核促进活性的60%和80%。在尿糖胺聚糖和经类似测试的多阴离子中也观察到类似的相对活性。因此，极化近端小管上皮细胞原代培养作为体外模型，可用于研究肾细胞产生的多阴离子大分子的结晶活性。
