内向矫正性钾通道Kir4.1和Kir7.1在大鼠睫状体的分布

目的:在蛋白水平探讨Kir4.1和Kir7.1在大鼠睫状体的分布情况。方法:用间接免疫荧光组织化学和免疫荧光双标记在冰冻切片上检测Kir4.1和Kir7.1在大鼠睫状体的分布和定位。结果:Kir4.1蛋白分布于睫状体的色素上皮细胞和无色素上皮细胞的胞质和胞膜,内层的无色素上皮细胞免疫活性较强,免疫双标显示Kir4.1蛋白与谷氨酰胺合成酶蛋白重叠分布,Kir4.1蛋白免疫活性在睫状体的扁平部和睫状突上无明显差异。Kir7.1蛋白分布于睫状体的无色素上皮细胞和睫状肌,与特异性标记睫状上皮的Ezrin蛋白双标显示Kir7.1分布在无色素上皮的基底面,其免疫活性在睫状突强表达,在睫状体扁平部弱表达。结论:Kir4.1和Kir7.1均分布于大鼠睫状体的无色素上皮的基底面,可能与房水的生成有重要关系。睫状肌的Kir7.1分布,与调节睫状肌的舒缩、参与房水的排出密切相关。

Localization of inwardly rectifying potassium channel Kir4.1 and Kir7.1 in rat ciliary body

Objective:To explore the localization of Kir4.1 and Kir7.1 in rat ciliary body at protein level.Methods:In- direct immunofluorescence was used to detect the distribution of Kir4.1 and Kir7.1 in rat ciliary body on frozen sec- tions,and double immunofluorescence was used to further determine their localization in the ciliary epithelium.Re- sults:Kir4.1 was distributed in the plasma and membrane of both pigment epithelial cells and non-pigment epithelial cells.The positive signal was higher in the inner non-pigment epithelial cells and co-localized with glutamine synthetase positive distribution.There was no difference between the expression of Kir4.1 in ciliary processes and the pars plaua of ciliary body.Kir7.1 was expressed in non-pigment epithelial cells and ciliary muscle,and at the basal membrane of non-pigment epithelial cells showed by double labeling with Ezrin.It was strongly expressed in ciliary process cells, but weakly expressed in the cells from the pars plaua of ciliary body.Conclusion.The localization of Kir4.1 and Kir7.1 in the basal membrane of ciliary non-pigment epithelial cells suggests that they may play an important role in maintai- ning the balance of K~ in the extracellular fluid of ciliary epithelium,promoting the influx of K~ ,and maintaining the resting potential of membrane and generation of aqueous fluid.The distribution of Kir7.1 in ciliary muscle suggests its role in regulating muscle contraction and the depletion of aqueous fluid.