REGULATION OF PHI AND FLUID FLUX IN CORNEAL ENDOTHELIUM

角膜内皮中 PHI 和流体流量的调节

• 批准号: 2162506
• 负责人: Joseph Aurelio Bonanno
• 金额: $ 14.65万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2162506
• 关键词: Fuchs' dystrophy; acidity /alkalinity; adenosinetriphosphatase; animal tissue; apical membrane; basolateral membrane; bicarbonates; biological fluid transport; biological transport; corneal endothelium; cow; fluorescent dye /probe; human tissue; intracellular transport; ion transport; lactates; membrane transport proteins; potassium; sodium; tissue /cell culture

Corneal hydration and transparency are dependent on the ion and fluid transport properties of the corneal endothelium. Fluid transport from stroma to aqueous humor is apparently coupled to the net transport of Na and HCO3 and is sensitive to the pH of the bathing solution. A complete model for ion coupled fluid transport however, is not available. Since extra- and intracellular [HCO3] are determined by extra- and intracellular pH (pHo and pHi), it is reasonable to suggest that any model of HCO3 transport will require an understanding of pHi regulation. This notion is supported by work showing that additions of drugs which are known to influence pHi regulation (amiloride and DIDS) also inhibit endothelial fluid transport. This study proposes to identify and characterize the pHi regulatory and HCO3- transport mechanisms present in fresh and cultured bovine corneal endothelial cells by utilizing the pH sensitive intracellular fluorescent probe, BCECF. Cells will also be grown on filter supports to allow independent access to apical and basal surfaces in order to determine the locations of the HCO3 transport mechanisms and establish a complete model for transendothelial HCO3- transport. Transendothelial fluid secretion can also be measured across filter cultures so that the HCO3- transport mechanisms essential for fluid transport and the transport mechanism-that is rate limiting for fluid flux can be identified. A long term goal is to identify agents or conditions that stimulate HCO3- transport and test their ability to stimulate fluid secretion as well. Lastly, post-surgical specimens of Fuch's Endothelial Dystrophy will be obtained and the pH regulatory and HCO3- transport capacities will be tested in order to determine if and how pump function is deranged in this disease. Once the transport deficit is identified, the long term goal is to test drugs which stimulate it or drugs that inhibit an opposing transport mechanism in order to enhance fluid secretion in this diseased endothelia.

角膜水合和透明度取决于离子和流体 角膜内皮的转运特性。 流体转运 基质到水幽默显然与Na的净运输耦合 和HCO3，对沐浴溶液的pH值敏感。 完整 但是，离子耦合流体传输的模型尚不可用。 自从 细胞内和细胞内[HCO3]由外部和 细胞内pH（pho和phi），合理的建议 HCO3运输模型将需要了解PHI调节。 该概念得到的工作得到了支持，表明添加药物 已知会影响PHI调节（Amiloride和Dids）也抑制 内皮流体转运。 这项研究建议识别和 表征存在的PHI调节和HCO3传输机制 新鲜和培养的牛角膜内皮细胞通过使用pH 敏感的细胞内荧光探针，BCECF。 细胞也将是 在过滤器支架上生长，以允许独立访问顶端和基础 表面以确定HCO3传输的位置 机理并建立了跨内皮HCO3-的完整模型 运输。 跨内皮液分泌也可以在 过滤培养物使HCO3-运输机制对于 流体运输和运输机构 - 这是限制的速率 可以识别流体通量。 一个长期目标是确定代理商或 刺激HCO3的条件 - 运输并测试其能力 还刺激流体分泌。 最后，外科手术标本 将获得Fuch的内皮营养不良症，并进行pH调节性和 HCO3-运输能力将进行测试，以确定是否和 该疾病中泵功能如何破坏。 一旦运输 确定了赤字，长期目标是测试药物 刺激它或抑制相反运输机制的药物 为了增强这种患病的内皮的液体分泌。