Sigmon D, Kumar S, Carpenter B, Miller T, Menon M, Scheid C
Department of Surgery, University of Massachusetts Medical School, Worcester 01655.
Am J Kidney Dis. 1991 Apr;17(4):376-80. doi: 10.1016/s0272-6386(12)80626-3.
To investigate the cellular mechanism(s) underlying kidney stone disease, we examined oxalate uptake in suspensions of renal cortical and papillary cells derived from control and stone-forming animals. In control animals, both cortical and papillary cells exhibited a time-dependent accumulation of oxalate. This uptake was mediated both by passive diffusion and by one or more transport processes sensitive to the anion transport inhibitor, DIDS. Oxalate uptake was also markedly sensitive to extracellular pH, showing increased uptake at acidic pH outside (pHo) (6.0), and reduced uptake at alkaline pHo (8.0). In renal tubular cells from stone-forming animals, oxalate uptake was markedly altered. Uptake was significantly reduced in cortical cells, whereas it was significantly stimulated in papillary cells from the same animals. Since the observed changes in oxalate handling occurred only in stone-forming animals, it is possible that alterations in renal cell oxalate transport contribute to calcium oxalate stone formation.
为了研究肾结石疾病潜在的细胞机制，我们检测了来自对照动物和结石形成动物的肾皮质和肾乳头细胞悬液中草酸盐的摄取情况。在对照动物中，皮质细胞和肾乳头细胞均表现出草酸盐的时间依赖性积累。这种摄取是由被动扩散以及对阴离子转运抑制剂DIDS敏感的一种或多种转运过程介导的。草酸盐摄取对细胞外pH也非常敏感，在细胞外酸性pH（pHo）为6.0时摄取增加，而在碱性pHo（8.0）时摄取减少。在结石形成动物的肾小管细胞中，草酸盐摄取明显改变。皮质细胞中的摄取显著减少，而同一动物肾乳头细胞中的摄取则受到显著刺激。由于观察到的草酸盐处理变化仅发生在结石形成动物中，因此肾细胞草酸盐转运的改变可能导致草酸钙结石的形成。
