Jennings M L
J Membr Biol. 1976 Aug 26;28(2-3):187-205. doi: 10.1007/BF01869697.
Transient extracellular pH changes accompany the exchange of chloride for sulfate across the erythrocyte membrane. The direction of the extracellular pH change during chloride efflux and sulfate influx depends on experimental conditions. When bicarbonate is present, the extracellular pH drops sharply at the outset of the anion exchange and tends to follow the partial ionic equilibrium described by Wilbrandt (W. Wilbrandt, 1942. Pfluegers Arch. 246:291). When bicarbonate is absent, however, the anion exchange causes the pH to rise, indicating that protons are cotransported with sulfate during chloride-sulfate exchange. The pH rise can be reversed by the addition of HCO(-3) (4 muM) or 2,4-dinitrophenol (90 muM). This demonstrates that the proton-sulfate cotransport can drive proton transport uphill. The stoichiometry of the transport is that one chloride exchanges for one sulfate plus one proton. These results support the titratable carrier model proposed by Gunn (Gunn, R.B. 1972, In: Oxygen Affinity of Hemoglobin and Red Cell Acid-Base Status. M. Rorth and P. Astrup, editors. p. 823. Munksgaard, Copenhagen) for erythrocyte membrane anion exchange.
短暂的细胞外pH变化伴随着氯离子与硫酸根在红细胞膜上的交换。氯离子外流和硫酸根内流过程中细胞外pH变化的方向取决于实验条件。当存在碳酸氢根时，在阴离子交换开始时细胞外pH会急剧下降，并倾向于遵循威尔布兰特（W. Wilbrandt，1942年。《普弗吕格氏文献》246:291）描述的部分离子平衡。然而，当不存在碳酸氢根时，阴离子交换会导致pH升高，这表明在氯离子-硫酸根交换过程中质子与硫酸根协同转运。加入4 μM的HCO₃⁻或90 μM的2,4-二硝基苯酚可使pH升高逆转。这表明质子-硫酸根协同转运可以驱动质子向上运输。运输的化学计量关系是一个氯离子与一个硫酸根加一个质子进行交换。这些结果支持了冈恩（Gunn，R.B. 1972年，载于《血红蛋白的氧亲和力和红细胞酸碱状态》。M. Rorth和P. Astrup编。第823页。蒙克斯gaard，哥本哈根）提出的红细胞膜阴离子交换的可滴定载体模型。
