TEAR GLAND FLUID FORMATION

泪膜对于视觉图像的质量是必需的 用于保护眼表。干眼症是主要的 眼部疾病的原因，以及房水的不足 泪膜的成分，由泪液产生 腺体与干眼症有很大比例的关系 案子。人们对其正常机制知之甚少。 泪液分泌功能。部分原因是特定的功能 缺陷尚未确定，目前的干眼治疗方法 必须依靠人工泪水替代。 拟议的研究将描述一种最近发现的 泪腺泡细胞功能方面，与刺激相关 钠泵酶Na，K-ATPase的重新分布。在 泪腺泡细胞，Na，K-ATPase，Na/H逆向转运蛋白，Cl/HCO3 抗转运蛋白和M碱乙酰胆碱受体存在于 基侧膜，至少在两个基本的 不同种类的细胞质池，第一个相对丰富的 基底膜表达的成分 Na，K-ATPase含量相对较高，其次是Na，K-ATPase。 在M受体激活后，Na，K-ATPase和 其他成分从细胞质池中动员出来， 转移到基底膜-侧膜。可用的数据包括 与这种整体移位的假设一致 过程分两步进行：从第一个细胞质池到 基侧膜，从第二池到第一池。 提出了识别Na，K-ATPase信号的实验方法 移位，以描述所涉及的步骤顺序，以 确定细胞质池的功能特性 Na、K-ATPase，并阐明它们之间的关系 移位现象与基底膜-侧膜循环。 实验设计将利用从大鼠身上分离出来的完整腺泡 眼眶外泪腺。这些结构保留了cell：cell 交界处和正常的顶端与底部-侧极。因为 腺泡可以在短期培养中保持2天，它 将有可能进行新陈代谢、液体相和表面- 标记程序，然后将腺泡替换为多维 结合差异性的亚细胞分离程序 沉淀法、密度梯度离心法和分割法 水相聚合物体系，它解决了一系列 亚细胞膜群。与此同时，它将是 可能将形态和免疫细胞化学联系起来 结果与分析分馏数据一致。

The tear film is necessary for the quality of the visual image and for protection of the ocular surface. Dry eye states are major causes of ocular morbidity, and deficiencies of the aqueous component of the tear film, which is produced by the lacrimal glands, have been implicated in a large proportion of dry eye cases. Little has been known about the normal mechanisms of lacrimal secretory function. In part because specific functional defects have not yet been identified, current dry eye treatments must rely on replacement with artificial tears. The proposed studies will characterize a recently discovered aspect of lacrimal acinar cell function, stimulation-associated redistribution of the sodium pump enzyme, Na,K-ATPase. In the lacrimal acinar cell, Na,K-ATPase, Na/H antiporters, Cl/HCO3 antiporters, and muscarinic acetylcholine receptors are present in the basal-lateral membranes, and in at least two fundamentally different kinds of cytoplasmic pools, the first relatively richer in the basal-lateral membrane-expressed constituents other than Na,K-ATPase, and the second relatively richer in Na,K-ATPase. Following activation of muscarininc receptors, Na,K-ATPase and other constituents are mobilized from the cytoplasmic pools and translocated to the basal-lateral membranes. Available data are consistent with the hypothesis that this overall translocation procedes in two steps: from the first cytoplasmic pool to the basal-lateral membrane, and from the second pool to the first. Experiments are proposed to identify signals for Na,K-ATPase translocation, to delineate the sequence of steps involved, to identify the functional properties of the cytoplasmic pools of Na,K-ATPase, and to clarify the relationship between these translocation phenomena and basal-lateral membrane recycling. The experimental design will utilize intact acini isolated from rat exorbital lacrimal glands. These structures retain cell:cell junctions and normal apical vs basal-lateral polarity. Because the acini can be maintained in short-term culture for up to 2 days, it will be possible to perform metabolic-, fluid phase-, and surface- labeling procedures, then subect the acini to a multidimensional subcellular fractionation procedure, incorporating differential sedimentation, density gradient centrifugation, and partitioning in aqueous polymer phase systems, which resolves a series of subcellular membrane populations. At the same time, it will be possible to correlate morphological and immunocytochemical results with the analytical fractionation data.