Objective To study potassium currents in isolated Deiters' cells of guinea pig cochlea and explore possible function of potassium current in Deiters' cell. Methods The whole cell patch clamp recording technique was used to study potassium currents of Deiters' cells in normal external solution and solutions with different K+ concentrations. We also studied the effects on reversal potentials and outward potassium currents. Results Isolated Deiters' cells possess voltage dependent, outwardly rectifying ion channels, which are K+ selective. 50?mmol/L K+ and 150?mmol/L K+ in external solution reduced IK-max from (10.06±2.2)nA (n=13) in normal external solution to (6.43±1.67)nA (n=6, P<0.05) and (5.49±1.33)nA (n=6, P<0.05), respectively. While the amplitude of tailcurrents decreased from (468.76±61.76)pA in 5?mmol K+ external solution to (224.74±35.89)pA (P<0.05) in 50?mmol/L K+ and to (-911.59±78.17)pA (P<0.01) in 150?mmol/L K+ external solution. Conclusions Outwardly rectifying potassium in Deiters' cells could buffer extracellular K+ in the small space between Deiters' cells and outer hair cells or neural fibers and participate in the diffusion of K+ from endolymph to perilymph.%目的 研究豚鼠耳蜗单离Deiters细胞的钾电流及其特性,探讨Deiters细胞钾电流可能的作用。rn方法 运用膜片钳技术，在全细胞膜式下记录正常细胞外液中钾电流，研究不同K +浓度的细胞外液对细胞反转电位和外向钾电流的影响。rn结果 单离Deiters细胞具有电压依赖的外向整流离子选择性通道；高钾外液使Deiters细胞外向钾电流幅度减小, 最大外向电流从正常外液的(10.06±2.2)nA(n=13)分别减少至(6.43±1.67)nA(n=6,P<0.05) （50mmol/L K +外液）和(5.49±1.33)nA(n=6, P<0.05)（150mmol/L K +外液）。同时尾电流的幅度减小，在5mmol/L K +外液中为（468.76±61.76）pA, 50mmol/L K +外液中为（224.74±35.89）pA (P<0.05)，在150mmol/L K +外液中尾电流转为内向，幅度为（-911.59±78.17）pA (P<0.01)。rn结论 Deiters细胞外向整流钾电流的作用可能是缓冲细胞周围间隙的钾离子浓度，并参与K +从内淋巴至外淋巴的运输。
展开▼
