链霉素对豚鼠耳蜗外毛细胞钙敏感外向钾电流的影响

Effects of Streptomycin on Calcium-Sensitive Outward Potassium Currents in Isolated Outer Hair Cells of Guinea Pig Cochlea

目的 :研究链霉素对豚鼠耳蜗外毛细胞底侧膜 K+ 电流的影响 ,以进一步揭示氨基甙类抗生素耳毒性的离子机制。方法 :全细胞膜片钳制技术。结果 :记录到 Ca2 + 敏感的外向 K+ 电流 [Ik(Ca) ];分别观察了 0 .1,1,10 ,10 0 ,10 0 0 μm ol/ L 链霉素对 Ca2 +敏感的外向 K+电流的影响。在指令电位 + 80 m V时 ,链霉素的抑制率分别为 0 ,(6 .72± 4.42 ) % ,(15 .5 4± 5 .43) % ,(18.0 2± 5 .32 ) % ,(30 .86± 11.2 1) %。结论 :链霉素以浓度依赖方式抑制 Ca2 +敏感的外向 K+电流 ,这可能是其急性耳毒性机制之一。

Objective:our purpose was to study the effects of streptomycin on calcium sensitive outward potassium currents in isolated outer hair cells of guinea pig cochlea. Methods:Whole cell patch clamp techniques were used. Results:Calcium sensitive outward potassium currents were recorded. When the concentrations of streptomycin were 0.1,1,10,100,1 000 μmol/L and the command potential was +80 mV, the inhibitory rates were 0,(6.72±4.42)%,(15.54±5 43)%,(18.02±5.32)%,(30.86±11.21)%. Conclusion:Streptomycin reduced I k(Ca) in a concentration dependent manner, which suggested that was one of the mechanisms of acute ototoxicity.