小鼠耳蜗侧壁α_2 Na,K-ATPase在听觉及年龄相关性听力下降中的作用

The Auditory Functions of α_2 Na,K-ATPase in the Lateral Wall of Mice Cochlea and Its Relation with Age-related Hearing Loss

目的探讨耳蜗侧壁α2Na,K-ATPase通道在听觉功能和年龄相关性听力减退中的作用。方法利用半拷贝基因的α2Na,K-ATPase+/-杂合子小鼠作为试验平台,采用听性脑干反应(ABR)和耳蜗内电位(endoco-chlear potential,EP)检测方法,对α2Na,K-ATPase+/-杂合子小鼠和α2Na,K-ATPase+/+野生型小鼠进行ABR和EP检测,并对各个鼠龄段的小鼠进行ABR检测。结果α2Na,K-ATPase+/-杂合子小鼠的听力和EP值均低于α2Na,K-ATPase+/+野生型鼠;α2Na,K-ATPase+/-杂合子小鼠的听力随鼠龄增长而逐渐下降,高龄期小鼠的ABR阈值与其低龄时相比显著性升高(P<0.05)。结论耳蜗侧壁的α2Na,K-ATPase通道对听觉功能具有重要作用;携带半拷贝基因的αNa,K-ATPase+/-杂合子小鼠表现出轻度年龄相关性听力减退。

Objective Using α2 Na, K - ATPase mouse model to assess the role of α2 Na, K - ATPase in auditory function and the relationship with age - related hearing loss（AHL）. Methods Auditory function of α2 Na, K - ATPase ^＋/ - mice and wild type mice were detected regularly by auditory brainstem response（ABR） and endocochlear potential（EP）. Results The mean value for ABR thresholds in response to stimulus was elevated in aged α2 Na, K- ATPase^＋/- mice, relative to that in younger α2 Na, K - ATPase^＋/＋ mice significantly （P〈 0.05） .The EP value of α2 Na,K - ATPase^＋/- mice was significantly decreased than that observed in α2 Na, K - ATPase^＋/＋ mice（ P 〈 0.05）. α2 Na, K - ATPase^＋/- mice showed a slightly progression of age - related hearing loss. Conclusion The α2 Na, K- ATPase in cochlear lateral wall is important to cochlear auditory function, α2 Na, K - ATPase gene maybe be responsible for the pathogenesis of Presbycnsis. Mice that expressed only one copy of α2 Na, K - ATPase may develop to AHL.