摘要
本文运用连续录像手段和荧光测钙技术研究丁胺卡那霉素对离体耳蜗外毛细胞运动及胞内游离钙浓度的影响。结果显示：（１）正常状态下外毛细胞内游离钙的荧光比值为１．３９±０．０９（ｘ±ｓｘ，ｎ＝１５）；从等渗环境进入低渗环境外毛细胞变短变粗（Ｐ＜０．０５，ｎ＝７。（２）丁胺卡那霉素（６．６７ｍｇ／ｍｌ）可使外毛细胞胞膜皱缩内陷，局部直径明显变细（Ｐ＜０．０１，ｎ＝１９），即使在低渗环境中也难以恢复原状。（３）丁胺卡那霉素（３．２３ｍｇ／ｍｌ）可瞬间降低细胞内钙离子浓度，使荧光比值降低１４．６８±２．０５％（Ｐ＜０．０１，ｎ＝１２）。提示丁胺卡那霉素的耳毒性作用机制可能通过降低细胞内游离钙浓度，进而影响外毛细胞钙依赖性的“慢能动性”
Abstract The effects of amikacin on intracellular free calcium and mobility in guinea pig cochlear outer hair cells were studied by aids of continuously monitored via video camera system and Fluorescent indicator Fura 2. The results showed that fluorescence intensity of intracelluar calcium in the control group was 1.39±0.09( n =15, ±s ),and the outer hair cells swelled and shortened in the hypotonic solution.The motile response of the outer hair cells was observed in the presence of 6.67 mg/ml amikacin,cell membrane shrank and caved in,and the diameter in part significantly decreased was also found( P <0.01, n =19).The changes in cell volume were not reversible to the hyposmotic pressure.The application of amikacin(3.23 mg/ml)to the incubition medium led to a decrease of intracellular free calcium (-14.68±2.05%, P <0.001, n =12).These observations suggest that the molecular mechanisms of amikacin ototoxicity possibly involved in reduction of intracellular free calcium which affected the calcium dependent actin mediated slow mobility of outer hair cells which depends on calcium. KEY WOEOS amikacin; mobility of outer hair cell; intracellular free calcium
出处
《中国应用生理学杂志》
CAS
CSCD
1998年第4期361-363,共3页
Chinese Journal of Applied Physiology
基金
江苏省自然科学基金
铁道部基金
