HOMEOSTATIC ABILITY OF THE RETINAL PIGMENT EPITHELIUM

视网膜色素上皮的稳态能力

• 批准号: 3072797
• 负责人: SHELDON S MILLER
• 金额: $ 5.29万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-09-01 至 1988-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3072797
• 关键词: biological fluid transport; cyclic AMP; dark adaptation; electrophysiology; fresh water environment; homeostasis; light adaptations; membrane permeability; microelectrodes; oxygen consumption; oxygen tension; retina; retina circulation; retinal pigment epithelium

This project has three principal objectives: (1) to specify the membrane transport and cellular mechanisms that help control the rate, direction and composition of the fluid transported by the pigment epithelium (PE); (2) to determine the PE transport mechanisms that help control calcium homeostasis in the subretinal and choroidal spaces; (3) to measure the O2 consumption of this metabolically active tissue with and without the retina attached, in the light and dark. An important hypothesis to be tested is that control of fluid secretion is mediated by cAMP activated increase in cell membrane C1 conductance. This idea will be examined in a series of microelectrode experiments. The fluid transport measurements will be carried out using the isolated PE-choroid of the frog and cat. Other experiments will determine which Ca transport mechanisms (e.g., ATP dependent pumps, exchangers, passive channels) control the movements of Ca across the apical and basal membranes of the PE. A series of transport and electrophysiological experiments will examine the interactions between the active and passive components of the Ca, K, and taurine transport systems. Finally, the O2 consumption of the PE-choroid will be measured and the dependence on active transport will be determined. The relationship between retinal activity and choroidal O2 tension will be studied using the isolated retinal PE-choroid preparation (frog). An O2 microelectrode will be used to monitor retinal activity in the light and dark, and the response of this electrode will be measured as a function of choroidal O2 tension. The life of the retina depends on a healthy, normal relationship to the pigment epithelium. In physiological terms, this means that O2, water, ions and metabolites are transported by the epithelium between the retinal and choroidal spaces and that changes in retinal activity and blood flow can modulate the activity of the epithelium. The proposed experiments are specifically designed to quantify this relationship when it is normal and when it has been severely altered. Hence, this work could have considerable significance for understanding diseases which affect the epithelium or the choriocapillaris.

该项目有三个主要目标：（1）指定膜 有助于控制速率，方向和的运输和蜂窝机制 颜料上皮（PE）转运的液体的组成； （2）至 确定有助于控制钙稳态的PE运输机制 在视网膜下和脉络膜中； （3）测量O2消耗 有和没有视网膜的代谢活性组织中， 在光线和黑暗中。 要测试的一个重要假设是 液体分泌的控制是由CAMP激活的细胞增加介导的 膜C1电导。 这个想法将在一系列 微电极实验。 流体传输测量将是 使用青蛙和猫的孤立的Pe-choroid进行。 其他 实验将确定哪种CA传输机制（例如ATP 依赖的泵，交换器，被动通道）控制CA的运动 跨PE的顶端和基底膜。 一系列运输和 电生理实验将检查 CA，K和牛磺酸传输系统的主动和被动组件。 最后，将测量PE-choroid的O2消耗，并 将确定对主动运输的依赖。 关系 在视网膜活性和脉络膜O2张力之间将使用 孤立的视网膜PE-螺状制剂（Frog）。 O2微电极将 用于监测浅色和黑暗中的视网膜活动，响应 该电极的测量将是脉络膜O2张力的函数。 视网膜的寿命取决于与 色素上皮。 用生理术语，这意味着O2，水， 离子和代谢产物由视网膜之间的上皮转运 和脉络膜空间以及视网膜活性和血流的变化 可以调节上皮的活性。 提出的实验是 专门设计用于量化这种关系的正常和 当它被严重改变时。 因此，这项工作可能有 对于影响影响的疾病的重要意义 上皮或绒毛膜。