Sziklai I
ENT Department, Semmelweis University Medical School, Budapest, Hungary.
Hear Res. 1996 May;95(1-2):100-7. doi: 10.1016/0378-5955(96)00027-5.
An otosclerotic peptide (OP) (Sziklai et al., 1985a.b) was purified from perilymph and stapes footplate of otosclerotic patients by Sephadex G-25 gel column chromatography and subsequent isotachophoretic (ITP) separation. The transfer function of the electromotility was measured by inserting the isolated outer hair cells (OHC) into a partitioning microchamber (Evans et al., 1991) and applying a series of pairs of brief square-pulse stimuli with opposite polarity and with increasing magnitude. Somatic length changes of the inserted part of the OHCs were measured by an optoelectronic system. The isotachophoretically homogeneous peptide exerted a gain and magnitude decreasing effect on the transfer function of electromotility of isolated OHCs of the guinea pig, in vitro. The operating point of the electromotility did not change due to the effect of the peptide. The peptide decreased the electromotile performance within a minute and bath exchange to normal saline did not completely restore the transfer curve to baseline. Application of caffeine to the cells already under the effect of the otosclerotic peptide produced an opposite effect: gain and magnitude increase. Simultaneous application of acetylcholine (ACh) did not antagonize the effect of OP. The underlying mechanism of the action of OP on the transfer function of electromotility of OHCs is postulated to involve the modulation of intracellular Ca2- concentration.
通过Sephadex G - 25凝胶柱色谱法以及随后的等速电泳（ITP）分离，从耳硬化症患者的外淋巴和镫骨足板中纯化出一种耳硬化肽（OP）（Sziklai等人，1985a，b）。通过将分离出的外毛细胞（OHC）插入分隔微室（Evans等人，1991）并施加一系列具有相反极性且幅度逐渐增加的短方波刺激对，来测量电运动的传递函数。通过光电系统测量OHC插入部分的体细胞长度变化。等速电泳均一的肽对豚鼠离体OHC的电运动传递函数具有增益降低和幅度降低的作用。电运动的工作点并未因该肽的作用而改变。该肽在一分钟内降低了电运动性能，用生理盐水进行浴液交换并不能使传递曲线完全恢复到基线。对已经受到耳硬化肽作用的细胞施加咖啡因产生了相反的效果：增益和幅度增加。同时施加乙酰胆碱（ACh）并未拮抗OP的作用。推测OP对OHC电运动传递函数作用的潜在机制涉及细胞内Ca2 +浓度的调节。
