Out-of-equilibrium CO2/HCO3− solutions and their use in characterizing a new K/HCO3 cotransporter
Out-of-equilibrium CO2/HCO3− solutions and their use in characterizing a new K/HCO3 cotransporter
复制标题
非平衡 CO2/HCO3− 溶液及其在表征新型 K/HCO3 协同转运蛋白中的应用
作者：
Jinhua Zhao;E. Hogan;M. O. Bevensee;W. Boron
在典型的生理溶液中，CO2与HCO 3 −和H+处于平衡状态（CO2 + H2O\[lrna] HCO 3 − + H+）。因为人们不能独立地改变CO2和HCO 3 −的浓度和pH值，所以不可能区分CO2和HCO 3 −对生理过程的影响。在这里，我们描述了一种连续流动、快速混合的方法，用于生成具有生理pH和CO2（但很少HCO 3-）或pH和HCO 3-（但很少CO2）的失衡CO2/HCO 3-溶液。我们已经利用这些失衡的解决方案将HCO 3-专门引入鱿鱼巨轴突的外部或内部，并验证了新的K/HCO 3协同转运蛋白的存在。这种非平衡方法可以在各种应用中用于独立控制CO2和HCO 3 −浓度和pH值。
IN typical physiological solutions, CO2 is in equilibrium with HCO3− and H+ (CO2 + H2O\[lrarr]HCO3− + H+). Because one cannot independently alter CO2 and HCO3− concentrations and pH, it is impossible to distinguish between the effects of CO2 and HCO3−on physiological processes. Here we describe a continuous-flow, rapid-mixing approach for generating out-of-equilibrium CO2/ HCO3− solutions with a physiological pH and CO2 (but little HCO3−), or pH and HCO3− (but little CO2). We have exploited these out-of-equilibrium solutions to introduce HCO3− exclusively to either the outside or inside of a squid giant axon, and verify the presence of a new K/HCO3 cotransporter. The out-of-equilibrium approach could be useful in a variety of applications for independently controlling CO2 and HCO3− concentrations and pH.