TEAR GLAND FLUID FORMATION

泪膜对于视觉图像的质量和对于 眼表的保护和干眼状态是眼内分泌失调的主要原因。 眼部发病率 泪液膜的含水成分的缺陷， 由泪腺产生的，已经被牵连在一个大的 干眼症的比例。 关于泪腺分泌 功能 因此，干眼症治疗必须依赖于用 人工泪液 泪液分泌的工作假设将在此评估 该项目由离子转运蛋白组成，预计将催化 外分泌腺中驱动渗透水分泌的电解质通量。 这些 包括：Na，K-ATPase，钠、钾和氯电导 途径，NaCl，NaKCl和KCl同向转运体，以及平行的Na/H和Cl/阴离子 反向转运体 大多数研究泪液分泌的常规方法利用完整的 组织或细胞制备物，其中不可能测量运输 通过根尖膜或区分替代 基底-外侧核中钠和氯的耦合转运机制 膜。 因此，以前不可能设计 模型的最终测试，以了解运输活动是如何 控制，或识别导致干眼症的特定运输缺陷。 在拟议的研究中，示踪剂吸收和分光光度法将 用于表征功能质膜中的转运过程 从大鼠眶外泪腺分离的囊泡。 这种方法 避免了常规制剂的技术局限性。 的 运输方法已经被有效地应用于囊泡 肾脏和肠道转运机制的研究。 离心和 聚合物相分配方法可用于分离外眶 腺体基底侧质膜作为保持运输的密封囊泡 完整的细胞膜系统。 分离程序还产生 囊泡人口暂时确定为顶膜。 在 与转运实验平行，免疫细胞化学研究基于 将对单克隆抗体进行检测，以验证该人群的 顶膜特性

The tear film is necessary for the quality of the visual image and for the protection of the ocular surface, and dry eye states are major causes of ocular morbidity. 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 is known about lacrimal secretory function. Consequently, dry eye treatments must rely on replacement with artificial tears. The working hypothesis for lacrimal fluid secretion to be evaluated in this project is comprised of ion transporters predicted to catalyze the electrolyte flux driving osmotic water secretion in exocrine glands. These include: Na,K-ATPase, sodium, potassium, and chloride conductance pathways, NaCl, NaKCl, and KCl symporters, and parallel Na/H and Cl/anion antiporters. Most conventional methods for studying lacrimal secretion utilize intact tissue or cell preparations, in which it is impossible to measure transport through the apical membranes or to distinguish between alternative mechanisms for coupled sodium and chloride transport in the basal-lateral membranes. Therefore, it has not previously been possible to design definitive tests of the model, to learn how the transport activities are controlled, or to identify specific transport defects causing dry eyes. In the proposed studies, tracer uptake and spectrophotometric methods will be used to characterize transport processes in functional plasma membrane vesicles isolated from the rat exorbital lacrimal gland. This approach will avoid the technical limitations of conventional preparations. The transport methodologies have already been productively applied in vesicle studies of renal and intestinal transport mechanisms. Centrifugation and polymer phase-partitioning methods are available for isolating exorbital gland basal-lateral plasma membranes as sealed vesicles retaining transport systems of the intact cell membrane. The isolation procedures also yield a vesicle population provisionally identified as apical membranes. In parallel with the transport experiments, immunocytochemical studies based on monoclonal antibodies will be performed to verify this population's apical membrane identity.