【摘要】 本文对豚鼠耳蜗离体外毛细胞的细胞活性及底侧膜处电压依赖性钾离子通道进行了研究，结果表明：（１）离体外毛细胞悬液保存在４℃时，可延长存活时间达７ｈ以上。（２）外毛细胞的静息电位：应用电流钳方法，在刚形成全细胞方式时其细胞内静息电位为－７３．７±６．９ｍＶ，２ｍｉｎ后为－９４．８±４．１ｍＶ（ｘ±ｓ，ｎ＝１０）。（３）全细胞方式记录到的电压依赖性外向Ｋ＋电流是由快钾电流和延迟整流钾电流两部分组成，快钾电流的激活电位为－６０～－５０ｍＶ，延迟整流钾电流的激活电位为－４０～－３０ｍＶ，电流－电压关系曲线呈“Ｓ形上升”趋势。外向Ｋ＋电流被ＴＥＡ（２０ｍｍｏｌ／Ｌ）阻断后，可观察到一种电压依赖性内向电流更多还原

【Abstract】 he cell viability and voltagedependent potassium currents were studied in the basolateral cell membrane of outer hair cells(OHCs) isolated from guineapig cochlea by using the whole cell configuration of the patchclamp techniques.The results were:(1).these cells in vitro could remained viable for up to 7 hours at the temperature 4℃;(2).the mean resting potentials were 73.7±6.9 mV on patch rupture and became 94.8±4.1 mV as the pipette contents equilibrated with the cell interior over 2 mins(±s,n=10);(3).depolarizing voltage steps from a holding potential of about 70 mV resulted in a time and voltagedependent complex outward currents.The outward currents were blocked by 20 mmol/Ltetraethylammonium chloride(TEA) in the bath.This indicated that the outward currents were mainly carried by potassium ions.The outward K+ currents had two components.A transient K+ current was activated by steps to 60～50 mV.Whereas a slow K+ currents,Ik,was activated by steps to 40～30 mV.The IV curve of Ik showed‘Sshaped’relationship.After blocking of outward K+ currents by adding TEA(20mmol/L) in extracellular solution,a time and voltagedependent inward current was clearly detectable.更多还原