Spicer S S, Schulte B A, Adams J C
Department of Pathology, Medical University of South Carolina, Charleston 29425.
Hear Res. 1990 Jan;43(2-3):205-17. doi: 10.1016/0378-5955(90)90229-i.
The distribution of two ion transport enzymes in the vestibular system was investigated immunocytochemically. Immunostaining demonstrated abundant Na+,K(+)-ATPase in the basolateral plasmalemma of all dark cells and of cuboidal (transitional) cells bordering maculae and planum semilunatum cells bordering cristae. Na+,K(+)-ATPase was also present in nerve terminals impinging on vestibular hair cells and around nerve fibers and ganglion cells. Na+,K(+)-ATPase containing cells with fine intertwining processes were found within the perilymphatic stroma beneath maculae and cristae. These cells and interspersed nerves form a distinct, highly cellular plate that lies under neurosensory epithelium selectively. The catalytic alpha subunit of Na+,K(+)-ATPase in vestibular epithelia differs antigenically from the alpha subunit in nerves and from the alpha subunit in salivary gland and renal epithelium. Carbonic anhydrase (CA) isozyme II was localized in the apex of all supporting cells in neurosensory epithelia. In contrast, CA II immunostaining varied in vestibular dark cells showing heterogeneity in ion transport activity among these cells. Immunostaining evidenced CA II also in perilymphatic stromal cells which were presumably fibroblastic in nature and which correspond in location with the Na+,K(+)-ATPase positive cells under the vestibular neurosensory epithelium.
采用免疫细胞化学方法研究了两种离子转运酶在前庭系统中的分布。免疫染色显示，在所有暗细胞的基底外侧质膜以及与黄斑相邻的立方形（过渡性）细胞和与嵴相邻的半月形细胞中，Na⁺,K⁺-ATP酶含量丰富。Na⁺,K⁺-ATP酶也存在于前庭毛细胞上的神经末梢以及神经纤维和神经节细胞周围。在黄斑和嵴下方的外淋巴基质中发现了含有Na⁺,K⁺-ATP酶且有精细交织突起的细胞。这些细胞和散布其中的神经形成了一个独特的、细胞高度密集的板层，选择性地位于神经感觉上皮下方。前庭上皮中Na⁺,K⁺-ATP酶的催化α亚基在抗原性上与神经中的α亚基以及唾液腺和肾上皮中的α亚基不同。碳酸酐酶（CA）同工酶II定位于神经感觉上皮中所有支持细胞的顶端。相比之下，CA II免疫染色在前庭暗细胞中有所不同，表明这些细胞的离子转运活性存在异质性。免疫染色还证明，在外淋巴基质细胞中也有CA II，这些细胞可能本质上是成纤维细胞，其位置与前庭神经感觉上皮下方的Na⁺,K⁺-ATP酶阳性细胞相对应。
