Ernst A, Reuter G, Zimmermann U, Zenner H P
Department of Otolaryngology, University of Tübingen, Germany.
Brain Res. 1994 Feb 4;636(1):153-6. doi: 10.1016/0006-8993(94)90191-0.
The acute effects of the aminoglycoside antibiotics gentamicin on isolated cochlear outer hair cells (OHC) was investigated by whole-cell patch-clamp and measurements of the intracellular potassium level by means of the potassium-sensitive dye PBFI. In addition, the accompanying length changes of OHC are described. It could be shown that gentamicin at different concentrations reversibly induces a hyperpolarization by about 5-10 mV, potassium outflow from the cytoplasm (by about 22 mM) and a cellular elongation (by about 10%). It is suggested that these effects are the result of an interaction between gentamicin and the cochlear transduction channels in OHC as suggested earlier. These acute effects are distinctly different from the chronic gentamicin effects which are based on the metabolization of the antibiotics to cause the death of the OHC by interaction with the phosphoinositide signalling cascade.
通过全细胞膜片钳技术以及使用钾敏感染料PBFI测量细胞内钾水平，研究了氨基糖苷类抗生素庆大霉素对离体耳蜗外毛细胞（OHC）的急性作用。此外，还描述了OHC伴随的长度变化。结果表明，不同浓度的庆大霉素可使细胞可逆性超极化约5 - 10 mV，使细胞质中的钾外流（约22 mM），并使细胞伸长（约10%）。正如之前所提出的，这些作用被认为是庆大霉素与OHC中的耳蜗转导通道相互作用的结果。这些急性作用与慢性庆大霉素作用明显不同，慢性作用是基于抗生素的代谢，通过与磷酸肌醇信号级联相互作用导致OHC死亡。
