地塞米松对气压创伤性中耳炎模型大鼠中耳黏膜上皮钠通道mRNA转录的影响

Dexamethasone Can Raise the Expression of ENaC in Middle Ear Mucosa of Barotrauma-induced Otitis Media in Rat

宗雨;李祥翠;张奕;李吉平;

1:上海交通大学医学院附属仁济医院耳鼻咽喉头颈外科

2:上海交通大学(医学院)耳鼻咽喉科研究所

摘要
目的探讨地塞米松对气压创伤性中耳炎模型大鼠中耳黏膜中上皮钠通道(epithelial sodium channel,ENaC)转录的影响。方法 18只清洁级SD大鼠随机分为为干预组、模型组及正常对照组,每组6只(12耳)。正常对照组未予任何处理,干预组及模型组通过增加环境气压制作气压创伤性中耳炎模型,干预组在造模后连续三天腹腔注射地塞米松(2mg/kg,加入生理盐水0.5ml)。在造模后第1、3、7天分别观察各组鼓膜形态变化;在造模后第七天取中耳黏膜,采用实时定量-聚合酶链反应(real time-polymerase chain reaction,Real time-PCR)检测各组大鼠中耳黏膜中ENaC转录情况。结果对照组大鼠各时间段鼓膜均未见明显异常。模型组第1天每只大鼠至少有一耳鼓室内充满琥珀色积液,鼓膜充血,松弛部膨出,可见小气泡;第3天时鼓室仍有琥珀色积液,以上鼓室为著,松弛部内陷,气泡消失;第7天时未见鼓室积液,鼓膜亦基本恢复正常。干预组第1天每只大鼠至少有一耳可见鼓室内充满琥珀色积液,鼓膜充血,松弛部膨出,可见小气泡;第3天时所有大鼠双耳均未见明显鼓室积液征,鼓膜浑浊;第7天时未见鼓室积液,鼓膜亦基本恢复正常。干预组大鼠中耳黏膜α-ENaC-mRNA、β-ENaC-mRNA、γ-ENaC-mRNA均上调,分别为模型组的2.04、2.56、2.00倍(P<0.01)。结论地塞米松能加速气压创伤性中耳炎模型大鼠中耳腔内积液的清除,增加ENaC在中耳黏膜中的基因转录,可能是糖皮质激素清除中耳腔积液的机制之一。
关键词
上皮钠通道;动物模型;气压创伤性中耳炎;地塞米松;实时定量-聚合酶链反应
基金项目(Foundation):
作者
宗雨;李祥翠;张奕;李吉平;
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