Klocke R A
J Appl Physiol. 1976 May;40(5):707-14. doi: 10.1152/jappl.1976.40.5.707.
The rate of exchange of bicarbonate and chloride ions across the red cell membrane was studied in a continuous flow rapid reaction apparatus at 37 degrees C. A transmembrane gradient both ions was produced by mixture of cells suspended in a solution of one ion with an isosmotic solution of the other ion. Carbonic anhydrase activity was inhibited by acetazolamide to prevent changes in CO2 concentration during the experiments. Chloride and bicarbonate efflux from cells were studied in separate experiments at each experimental pH. Using a least squares technique, values of chloride and bicarbonate permeabilities were fitted to each pair of independent experiments. Chloride permeability averaged 1.1 (+/- 0.2 SD) X 10-4 cm/s and was not affected by change in pH. Recovered bicarbonate permeabilities varied widely, always remaining at least fivefold greater than chloride permeability. While bicarbonate permeability could not be accurately characterized, it appears to be greater than chloride permeability. Analysis of CO2 transfer with the estimated permeabilities indicates that the bicarbonate-chloride exchange by itself probably does not limit CO2 transfer.
在37摄氏度下，使用连续流动快速反应装置研究了红细胞膜上碳酸氢根离子和氯离子的交换速率。通过将悬浮在一种离子溶液中的细胞与另一种离子的等渗溶液混合，产生了两种离子的跨膜梯度。实验过程中，用乙酰唑胺抑制碳酸酐酶活性，以防止二氧化碳浓度发生变化。在每个实验pH值下，分别进行实验研究细胞中氯离子和碳酸氢根离子的外流情况。采用最小二乘法，将氯离子和碳酸氢根离子的渗透率值与每对独立实验进行拟合。氯离子渗透率平均为1.1（±0.2标准差）×10⁻⁴厘米/秒，且不受pH值变化的影响。恢复后的碳酸氢根离子渗透率变化很大，始终至少比氯离子渗透率大五倍。虽然碳酸氢根离子渗透率无法准确表征，但似乎大于氯离子渗透率。用估计的渗透率分析二氧化碳转运表明，碳酸氢根离子-氯离子交换本身可能并不限制二氧化碳的转运。
