依托咪酯对氯化钾和咖啡因诱发豚鼠耳蜗外毛细胞内钙离子移动的影响  

The Effect of Etomidate on Ca^(2+) Mobilization Induced by KCl or Caffeine in Isolated Outer Hair Cells in Guinea Pigs

作　　者：李元涛[1] 黄穗萍[1] 黄晓雷[1] 吴铭广[1] 李亚文[1] 王芳 周龙[3] 

机构地区：[1]南方医科大学附属深圳妇幼保健院麻醉科,深圳518028 [2]南方医科大学附属深圳妇幼保健院内科,深圳518028 [3]郧阳医学院附属太和医院麻醉科,十堰442000

出　　处：《华中科技大学学报（医学版）》2010年第2期246-248,共3页Acta Medicinae Universitatis Scientiae et Technologiae Huazhong

基　　金：湖北省教育厅重点资助项目(No.D200524008);湖北省卫生厅科研基金指导性项目(No.JX2C32)

摘　　要：目的观察不同浓度依托咪酯对氯化钾和咖啡因诱发的豚鼠耳蜗外毛细胞内钙离子移动的影响,探讨其对听觉外周感受器(耳蜗)作用的可能机制。方法①30个活性良好的外毛细胞随机分为3组(n=10):对照组(C组)、低浓度依托咪酯组(E1组)、高浓度依托咪酯组(E2组),用Fluo-3AM荧光指示剂染色,分别给予Hanks液、50、100μmol/L依托咪酯预处理20 min。在激光共聚焦显微镜下动态观察各组预处理前、后以及40 mmol/L氯化钾诱发的细胞内钙荧光染色强度峰值的变化。②分组同①,观察各组预处理前、后以及20 mmol/L咖啡因诱发的细胞内钙荧光染色强度峰值的变化。结果①C组加入40 mmol/L氯化钾后细胞内钙荧光强度峰值从基础值105上升至221(P<0.01),E1组从基础值101上升至187(P<0.01),E2组从基础值103上升至150(P<0.01),E1组、E2组峰值分别较C组下降了近15.4%(P<0.05)和32.1%(P<0.01)。②C组加入20 mmol/L咖啡因后细胞内钙荧光强度峰值从基础值112上升至154(P<0.05),E1组从基础值103上升至148(P<0.05),E2组从基础值104上升至143(P<0.05)。但E1组和E2组细胞内钙荧光强度峰值较C组差异无显著性意义(P>0.05)。结论依托咪酯可浓度依赖性地抑制耳蜗外毛细胞电压依赖性Ca2+通道开放,减少胞外钙内流,降低耳蜗外毛细胞内钙离子浓度,而对内质网Ryanodine型钙库无明显影响。Objective To study the effect of etomidate on Ca2＋ mobilization induced by KCl or caffeine in isolated outer hair cells（OHC） in guinea pigs,to elucidate the effect of etomidate on cochleas.Methods The cells were divided into 3 groups,and 10 OHCs were assessed for each group,i.e.the control group（group C）,etomidate（50 μmol/L） group（group E1） and etomidate（100 μmol/L） group（group E2）.The OHCs were stained for 40 min with Fluo-3AM in the 6 mol/L esterification form.Groups E1 and E2were respectively preconditioned with 50 and 100 μmol/L etomidate and retained for 20 min.The Hanks culture fluid alone was turned on in the group C for duration of 20 min.The effects of etomidate（50,100 μmol/L） on changes of intracellular Ca2＋ fluorescent intensity induced by 40 mmol/L KCl or 20 mmol/L caffeine were investigated by laser scanning confocal microscope.Results ①After addition of KCl in group C,the basic value of the intracellular Ca2＋ fluorescent intensity was increased from 105 up to 221（P0.01）,from 101 up to 187 in group E1（P0.01）,from 103 up to 150 in group E2（P0.01）,and the peak value in groups E1 and E2 was respectively decreased with a ratio of approximate 15.4% and 32.1%,compared to group C（P 0.01）;②After adding caffeine into group C,the intracellular Ca2＋ fluorescent intensity was increased,from 112,the basic value,up to 154（P0.05）,from 103 up to 148 in group E1（P0.05）,and from 104 up to 143 in group E2（P0.05）,but there was no significant difference in the peak value between groups E1 or E2 and group C（P0.05）.Conclusion Etomidate dose-dependently decreased Ca2＋ transsarcolemmal influx through calcium channel in isolated OHCs in guinea pigs,but it had no significant influence on ryanodine-sensitive Ca2＋ stores of endoplasmic reticulum.

关 键 词：依托咪酯 细胞内钙离子 外毛细胞 耳蜗 豚鼠 

分 类 号：R329.2[医药卫生—人体解剖和组织胚胎学]