VOLUME REGULATION IN CORNEAL ENDOTHELIUM

角膜内皮的体积调节

• 批准号: 2545875
• 负责人: SANGLY P SRINIVAS
• 金额: $ 11.79万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-30 至 1999-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2545875
• 关键词: acid base balance; aminoacid; animal tissue; biological signal transduction; cell morphology; cell osmotic pressure; corneal endothelium; fluorescent dye /probe; high performance liquid chromatography; hyperglycemia; hypoxia; intraocular aqueous flow; intraocular pressure; ion transport; laboratory rabbit; light scattering; nuclear magnetic resonance spectroscopy; physiologic stressor; second messengers; sorbitol; water flow

Maintenance of cell volume is a homeostatic process expressed in all animal cells. The necessary water movement across the plasma membrane is coupled to solute transport mechanisms that are also involved in other cellular activities such as the accumulation of glucose, pHi regulation or vectorial fluid transport. The corneal endothelium is endowed with an active ion pump mechanism responsible for vectorial fluid transport and hence the maintenance of corneal hydration, a determinant of corneal transparency. Since this fluid transport and cell volume regulation must be intertwined, it is imperative to establish the mechanisms of volume maintenance and regulation to obtain a complete understanding of the fluid transport. In addition, it is of clinical significance to understand how fluid transport is affected during times of osmotic stress such as during contact lens wear and diabetes. The focus of this study is to establish the principles of volume regulation upon acute and sustained disturbances leading to short and long term volume regulations, respectively/ Short term volume regulation will be studied by following changes in cell volume and intracellular ionic activities to identify the mechanisms and second messengers involved. Experiments will employ anisosmotic perturbations, acidosis, hypoxia, ion substitutions and transport-specific inhibitors. Long term volume regulation will be examined in the context of adaptation to sustained anisosmotic loads by adjusting the levels of organic osmolytes (such as amino acids, myo-inositol and sorbitol). Isolated in vitro rabbit corneas and cultured bovine endothelial cells that are confluent and polarized on either glass coverslips or permeable supports will be used. The dynamics of cell volume will be measured using athe sensitive light scattering technique and by following the concentration of a fluorescent dye used as a volume marker. The long term goal of this study is to understand the interaction of the fluid transport, pHi regulation and volume regulation activities of the corneal endothelium under normal conditions and during metabolic stress, hyperglycemia and anisosmotic loads.

细胞体积的维护是所有动物中表达的稳态过程 细胞。穿过质膜的必要水运动是耦合的 溶解也参与其他细胞的运输机制 诸如葡萄糖，PHI调节或媒介物的积累之类的活动 流体传输。角膜内皮赋予活性离子 负责矢量流体运输的泵机制，因此 维持角膜水合，角膜透明度的决定因素。 由于必须将这种流体传输和细胞体积调节交织在一起，因此 必须建立数量维护和 调节以完全了解流体运输。在 此外，了解流体运输方式是临床意义 在渗透压力时受到影响，例如在隐形眼镜磨损期间 和糖尿病。这项研究的重点是建立 急性和持续干扰后的体积调节导致短暂 分别/长期法规/短期体积 通过以下细胞体积的变化和 细胞内离子活性以识别机制和第二 涉及的使者。实验将采用各向异性扰动， 酸中毒，缺氧，离子取代和转运特异性抑制剂。 长期体积法规将在适应的背景下进行检查 通过调节有机渗透液的水平来维持阳极载荷 （例如氨基酸，肌醇和山梨糖醇）。孤立的体外兔子 汇合和培养的牛内皮细胞，汇合和 将使用玻璃盖板上的两极分化或可渗透支撑。 细胞体积的动力学将使用敏感的光进行测量 散射技术并遵循荧光的浓度 染料用作音量标记。这项研究的长期目标是 了解流体转运，PHI调节和 角膜内皮在正常下的体积调节活性 条件和代谢应激期间，高血糖和动态性 负载。