外淋巴钙离子对畸变产物耳声发射的影响

The effect of calcium ion in perilymphatic fluid on guinea pig's distortion product otoacoustic emissions

目的研究外毛细胞运动产生畸变产物耳声发射（ＤＰＯＡＥ）的机理。方法观察９只豚鼠（１１耳）采用无钙和有钙的人工外淋巴灌流外淋巴腔后ＤＰＯＡＥ的变化。结果用无钙人工外淋巴灌流后ＤＰＯＡＥ的均值从４１．３ｄＢＳＰＬ降至１３．７ｄＢＳＰＬ，再用正常钙浓度的外淋巴灌流后又可回升到３６．７ｄＢＳＰＬ。结论ＤＰＯＡＥ的产生需外淋巴中正常浓度的钙离子为必要条件。提示外毛细胞在产生ＤＰＯＡＥ中并非以毛细胞的电运动性机制起作用，而是与一般肌纤维相似的收缩机理起作用，需要钙离子的中介。

Objective To study the mechanism of the production of distortion product otoacoustic emissions (DPOAE) by electromobility of out hair cell. Methods The changes of nine gninea pig's DPOAE by means of perfusion of artificial perilymphatic fluid with and without calcium ion were observed. Results The mean value of DPOAE decreased from 41.3 dB to 13.7 dB after perfusion of fluid devoid of calcium ion, it revived to 36.7 dB after reperfusion with normal perilymphatic fluid. The result supports Pickle's muscle theory for DPOAE′s mobile mechanism and does not support Brownell′s electromobility theory. Conclusion A normal concentration of calcium ion in perilymphatic fluid is necessary for outer hair cell to produce DPOAE.