七氟醚对豚鼠耳蜗外毛细胞Ca^2＋跨膜内流和内质网钙释放功能的影响  

Effects of sevoflurane on Ca^2＋ transsarcolemmal influx and Ca^2＋ release function of endoplasmic reticulum in isolated outer hair cells of guinea pigs

作　　者：李元涛[1] 杨京利[1] 周龙[1] 王燕[1] 罗向红[1] 刘菊英[1] 

机构地区：[1]郧阳医学院附属太和医院麻醉科,湖北省十堰市442000

出　　处：《中华麻醉学杂志》2008年第5期427-429,共3页Chinese Journal of Anesthesiology

基　　金：湖北省教育厅重点资助项目（D200524008）;湖北省卫生厅科研基金指导性项目（JX2C32）

摘　　要：目的观察七氟醚对豚鼠耳蜗外毛细胞Ca^2＋跨膜内流和内质网钙释放功能的影响，探讨其对听觉外周感受器（耳蜗）作用的可能机制。方法第一部分成年豚鼠，雌雄不拘，迅速断头，取耳蜗，酶孵育后，机械分离法分离外毛细胞，30个活力良好的外毛细胞随机分为3组（n=10）：对照组（C组）、低浓度七氟醚组（S1组）和高浓度七氟醚组（S1组），用Fluo-3AM钙荧光指示剂染色后，分别给予纯氧、1．7％七氟醚、3．4％七氟醚处理20min，然后加入40mmol／L氯化钾，测定细胞内游离钙离子浓度（[Ca^2＋]i）。第二部分以20mmol／L咖啡因代替氯化钾，其余处理及分组同第一部分。结果第一部分与基础值比较，各组给予七氟醚后[Ca^2＋]．差异无统计学意义（P〉0．05），加入氯化钾后[Ca^2＋]．升高（P〈0．01）；S1组和S2组加入氯化钾后[Ca^2＋]．低于C组，且S2组低于S1组（P〈0．05）。第二部分与基础值比较，各组给予七氟醚后[Ca^2＋]．差异无统计学意义（P〉0．05），加入咖啡因后[Ca^2＋]．升高（P〈0．0）；加入咖啡因后各组[Ca^2＋]．差异无统计学意义（P〉0．05）。结论七氟醚可浓度依赖性地抑制豚鼠耳蜗外毛细胞电压依赖型Ca^2＋通道开放，而对内质网Ryanodine敏感性钙释放功能无影响。Objective To investigate the effects of sevoflurane on Ca^2＋ transsarcolemmal influx and Ca^2＋ release function of endoplasmic reticulum in isolated outer hair cells （OHCs） of guinea pigs and the possible mechanism by which sevoflurane acts on cochleas. Methods The experiment was performed in 2 parts. In experiment Ⅰ twelve adult guinea pigs （8 male, 4 female） weighing 180-230 g were used. OHCs were mechanically separated after enzymatic incubation. Thirty OHCs with favorable activity were divided into 3 groups （ n = 10 each） ： group Ⅰ control （C） ; group Ⅱ low concentration sevoflurane （ 1.7 % , group S, ） and group Ⅲ high concentration sevoflurane （3.4% ,group S2 ）. The OHCs were stained with 6μmol/L Fluo-3AM in esterified form for 40 min. Group S1 and S2 were pretreated with 1.7% and 3.4% sevoflurane respectively for 20 min. KCl 40 mmol/L was then added. The intracellular ionized Ca^2＋ concentration （ [Ca^2＋] i） was determined by intracellular Ca^2＋ fluorescent intensity using laser scanning confocal microscope The protocol of the experiment It was the same as the experiment Ⅰ . The only difference was that caffeine 20 mmol/L was added instead of KCl 40 mmol/L. Results In experiment Ⅰ： tbere was no significant difference in baseline [ Ca^2＋ Ⅰ i and [ Ca^2＋ ] i after being exposed to sevofluraue among the 3 groups. [ Ca^2＋ ] i was significantly increased after addition of KCl as compared with the baseline [Ca^2＋ i and was significantly lower in group S1 and S2 than in group C and was the lowest in group S2 In experiment Ⅱ ： the [ Ca^2 ＋ ] i was significantly increased after addition of caffeine but there was no significant difference in [ Ca^2＋ ]i among the 3 groups. Conclusion Sevoflurane can inhibit voltagedependent Ca^2＋ channel opening in a concentration-dependent manner but can not affect ryanodine-sensitive Ca^2＋ release function of endoplasmic reticulum in isolated outer hair cells of guinea pigs.

关 键 词：钙通道 内质网 毛细胞 外 耳蜗 七氟醚 

分 类 号：R96[医药卫生—药理学]