Song Jae-Jun, Kown Seong Keun, Kim Eo-Jin, Lee Yung-Seop, Kim Bo-Yeon, Chae Sung-Won
Department of Otorhinolaryngology-Head and Neck Surgery, Dongguk University International Hospital, Goyang, Gyeonggi, Republic of Korea.
Int J Pediatr Otorhinolaryngol. 2009 Nov;73(11):1589-93. doi: 10.1016/j.ijporl.2009.08.011. Epub 2009 Sep 3.
We investigated the expression of the epithelial sodium channel (ENaC) and aquaporins (AQPs) in the middle ear mucosa of a rat model of otitis media with effusion caused by surgical obstruction of the Eustachian tube.
Sixty-four rats were randomly assigned to either undergo unilateral Eustachian tube obstruction (groups 1, 2, and 3) or to undergo no procedure (control group). Bony Eustachian tubes were approached through ventral incisions and obstructed with electrocautery. On days 14, 28, and 56, the ears were evaluated, and the rats were sacrificed for otoscopic evaluation and real-time RT-PCR. Immunohistochemistry was done for ENaC-alpha and AQP-1.
The level of ENaC-alpha expression decreased 0.28- and 0.73-fold at 2 and 4 weeks, respectively, but increased 1.48-fold at 8 weeks (p<0.05). The change in ENaC-beta expression at 2 weeks was insignificant. However, the level of ENaC-beta expression increased 3.17- and 7.85-fold at 4 and 8 weeks, respectively (p<0.05). The level of ENaC-gamma expression increased 1.51-, 4.82- and 14.79-fold at 2, 4 and 8 weeks, respectively (p<0.05). The level of AQP-1 expression decreased 0.10- and 0.04-fold at 4 and 8 weeks, respectively (p<0.05). The change in AQP4 expression at 4 and 8 weeks was insignificant (p>0.05). The pattern of immunoreactivity of ENaC-alpha and AQP-1 was similar with that of gene expression.
The experimental methods provoked reproducible otitis media with effusion. This model is well suited for studies of middle ear homeostasis during disease pathogenesis. Middle ear mucosa homeostasis is altered significantly by ETO, and the subunits of AQP proteins show a characteristic expression pattern over time.
我们研究了在因咽鼓管手术阻塞导致的中耳积液大鼠模型中，上皮钠通道（ENaC）和水通道蛋白（AQP）在中耳黏膜中的表达情况。
64只大鼠被随机分为两组，一组接受单侧咽鼓管阻塞（第1、2和3组），另一组不进行任何操作（对照组）。通过腹侧切口暴露骨性咽鼓管，用电灼法进行阻塞。在第14、28和56天，对耳朵进行评估，并处死大鼠进行耳镜检查和实时逆转录聚合酶链反应（RT-PCR）。对ENaC-α和AQP-1进行免疫组织化学检测。
ENaC-α的表达水平在第2周和第4周分别下降了0.28倍和0.73倍，但在第8周增加了1.48倍（p<0.05）。第2周时ENaC-β表达的变化不显著。然而，ENaC-β的表达水平在第4周和第8周分别增加了3.17倍和7.85倍（p<0.05）。ENaC-γ的表达水平在第2、4和8周分别增加了1.51倍、4.82倍和14.79倍（p<0.05）。AQP-1的表达水平在第4周和第8周分别下降了0.10倍和0.04倍（p<0.05）。第4周和第8周时AQP4表达的变化不显著（p>0.05）。ENaC-α和AQP-1的免疫反应模式与基因表达模式相似。
实验方法引发了可重复的中耳积液。该模型非常适合用于研究疾病发病机制期间的中耳内环境稳态。咽鼓管阻塞显著改变了中耳黏膜的内环境稳态，AQP蛋白亚基随时间呈现出特征性的表达模式。
