4-acetamido-4--isothiocyanatostilbene-2-2--disulfonic-acid and Kidney-Calculi

We established a method of human red blood cell oxalate influx rate under the condition of steady state exchange. Using this method we measured the influx rate in 10 patients with recurrent calcium oxalate nephrolithiasis and in 18 controls. DIDS inhibited oxalate flux across the human red blood cell membrane. This result suggested that band 3 protein mediates oxalate transport. Oxalate influx rate depended on reaction temperature and pH of reaction buffer. Although the oxalate influx rate in 4 degrees C could not be determined under an initial condition rate, the measurable condition was in 0 degrees C of reaction temperature. Consequently we measured the oxalate influx rate under the condition of 0 degrees C reaction temperature and 20 ml volume of washing buffer. The mean oxalate influx rate was significantly higher in patients with nephrolithiasis than in controls (-1.00 +/- 0.19 vs. -0.78 +/- 0.14).

Topics: 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; Adult; Aged; Anion Exchange Protein 1, Erythrocyte; Biological Transport; Calcium Oxalate; Cells, Cultured; Erythrocyte Membrane; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Male; Middle Aged; Temperature

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.

Topics: 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; Animals; Biological Transport; Hydrogen-Ion Concentration; In Vitro Techniques; Kidney Calculi; Kidney Cortex; Kidney Medulla; Kidney Tubules; Male; Oxalates; Rats; Rats, Inbred Strains