Na-K-2Cl联合转运子1在小鼠耳蜗侧壁组织中的表达及意义

目的观察Na-K-2Cl联合转运子1(NKCC1)在小鼠耳蜗组织中的表达及分布,并探讨其与耳蜗听觉功能的关系。方法选用健康正常CBA/CaJ小鼠为实验组,NKCC1-/-(突变纯合子,全基因敲除)小鼠为对照组,利用听性脑干反应检测两组动物的听觉功能,取各组小鼠的耳蜗行冰冻切片,同时采用免疫组织化学技术和免疫荧光组织化学法检测Na-K-2Cl联合转运子1在实验组与对照组小鼠的耳蜗中的表达和分布。结果实验组小鼠的ABR反应阈值为18±3.50dBSPL、对照组小鼠在100dBSPL刺激时无反应。NKCC1阳性反应呈棕黄色,主要分布于实验组小鼠耳蜗血管纹边缘细胞和螺旋韧带下部,在耳蜗血管纹边缘细胞和螺旋韧带下部的纤维细胞、纹上区也有适度表达,而在对照组未见阳性表达。图像分析显示,两组灰度值差异有显著统计学意义(P<0.01)。结论在正常小鼠耳蜗,Na-K-2Cl联合转运子1主要在血管纹边缘细胞及螺旋韧带下部分布表达,并与耳蜗听觉生理功能密切相关。

Immunohistochemical Localization of Na-K-2Cl Co-transporter in Mouse Cochlear Lateral Wall and Its Significance in Hearing

Objective To study the expression and distribution of NKCC1 (Na-K-2Cl, Co-transporter) in mice and investigate the relationship between NKCC1 and hearing function. Methods Auditory brain response (ABR) were recorded from animals and the expression of NKCC1 in the stria vascularis was examined with immunohistochemical staining.Results Strong expression of NKCC1 channel protein was found on the basolateral membrame of marginal cells of the stria vascularis as well as the fibrocytes in the inferior portion of the spiral ligament.NKCC1 immunoreactive were also observed in some regions. The control group had not positive expression. There was significant difference as compared with the control group (P<0.01).Conclusion NKCC1, mainly expresses in the marginal cells of the stria vascularis, and the fibrocytes of the spiral ligament, suggesting that the NKCC1 might play an important role in maintainence of hearing physiologic function.