[乙酰胆碱和三磷酸腺苷诱导的豚鼠耳蜗孤立外毛细胞及Deiters细胞电流]

[ACh and ATP-induced current in isolated outer hair cells and Deiters' cells of guinea pig cochlea].

作者信息

Yang J, Wang J

机构信息

Department of Otorhinolaryngology Head and Neck Surgery, Renji Hospital, Shanghai Second Medical University, Shanghai 200001, China.

出版信息

Zhonghua Er Bi Yan Hou Ke Za Zhi. 2001 Dec;36(6):418-21.

PMID:12761954

Abstract

OBJECTIVE

To determine ACh- and ATP-induced currents in isolated outer hair cells of guinea pig cochlea, respectively.

METHOD

The whole-cell patch-clamp technique was used to investigate potential and concentration dependence of ACh- and ATP-induced ion currents.

RESULTS

ACh(100 mumol/L) induced an early inward current followed by a late outward current when the cells were voltage-clamped at -70 mV. Only outward current occurred when potential was over -60 mV and its reversal potential was (-80 +/- 5.61) mV(n = 6). When depolarization protocols were applied, amplitude of inward currents activated by ATP(100 mumol/L) decreased and reversed at (3.2 +/- 0.23) mV(n = 8). Ion currents activated by ATP (100 mumol/L) were also recorded from isolated Deiters' cells.

CONCLUSION

ACh-induced outward current was carried by K+ and ATP-induced inward current was through non-selective cations channel. Effects of ACh and ATP on OHCs were voltage dependent.

摘要

目的

分别测定豚鼠耳蜗孤立外毛细胞中乙酰胆碱（ACh）和三磷酸腺苷（ATP）诱导的电流。

方法

采用全细胞膜片钳技术研究ACh和ATP诱导的离子电流的电位和浓度依赖性。

结果

当细胞在-70 mV电压钳制时，100 μmol/L的ACh诱导出一个早期内向电流，随后是一个晚期外向电流。当电位超过-60 mV时仅出现外向电流，其反转电位为（-80±5.61）mV（n = 6）。当应用去极化方案时，100 μmol/L的ATP激活的内向电流幅度减小，并在（3.2±0.23）mV处反转（n = 8）。从孤立的Deiters细胞中也记录到了100 μmol/L的ATP激活的离子电流。