异丙酚对氯化钾和咖啡因诱发豚鼠耳蜗外毛细胞钙离子移动的影响

目的:评价异丙酚对氯化钾和咖啡因诱发豚鼠耳蜗外毛细胞钙离子移动的影响,探讨其对听觉外周感受器(耳蜗)的作用。方法:急性分离豚鼠耳蜗外毛细胞,选择30个活力较高的外毛细胞,随机分为3组(n=10):对照组(C组)、30μmol/L异丙酚组(P1组)和100μmol/L异丙酚组(P2组)。用Fluo-3AM钙荧光指示剂染色后,P1组和P2组分别给予30、100μmol/L异丙酚或咖啡因处理5min,然后加入氯化钾,采用激光共聚焦显微镜测定细胞内荧光强度的峰值,反映细胞内游离钙离子浓度(Ca2+]i)的变化。结果:异丙酚可抑制氯化钾诱发的Ca2+]i增加并与浓度呈正相关,而对咖啡因诱发的Ca2+]i增加无明显影响。结论:异丙酚可抑制豚鼠耳蜗外毛细胞Ca2+跨膜内流,降低Ca2+]i,而对内质网功能无明显影响。

Effect of propofol on Ca2+ mobilization induced by KCI or caffeine in isolated outer hair cells of cochlea in guinea-pigs

Objective:To evaluate the effect of propofol on Ca2+ mobilization induced by KCl or caffeine in isolated outer hair cells(OHCs) of cochlea in guinea-pigs. Methods: Sixty OHCs were isolated, and stained with Fluo-3AM. The effects of propofol(30 and 100μmol/L) on changes in intracellular Ca2+(Ca2+]i) fluorescent intensity induced by KCl or caffeine were determined with laser scanning confocal microscope. Results:Ca2+]i in OHCs was not affected by propofol butpropofol inhibited the increase in Ca2+]i induced by KCl in a concentration-dependent manner. Propofol had no effect on the increase in Ca2+]i induced by caffeine. Conclusion: Propofol can decrease Ca2+]i in isolated OHCs in guinea-pigs probably by decreasing Ca2+ transsarcolemmal influx through calcium channel. But propofol shows little effect on endoplasmic reticulum function.