Rat Retina-RPE-Choroid Preparation: Electrophysiological

大鼠视网膜-RPE-脉络膜制备：电生理学

• 批准号: 7322459
• 负责人: sheldon s miller
• 金额: --
• 依托单位: NATIONAL EYE INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7322459
• 关键词: Rat; Retina; RPE; Choroid; Preparation

The RPE is a monolayer of pigmented cells that interact with retinal photoreceptors and helps maintain visual function. We have developed a new preparation to study RPE physiology in rat that includes the neural retina. The retina-retinal pigment epithelium-choroid (R-RPE-Ch) preparation was mounted in an Ussing chamber which allowed independent perfusion of retinal and choroidal baths. The intact monolayer had a mean (+/- SD) transepithelial potential of 4.3 +/- 1.0 mV and a total transepithelial resistance of 152 +/- 37 ohm*cm^2 (n =10). As in other mammalian RPE preparations, we found barium-sensitive K channels at the apical and basolateral membranes. Intracellular microelectrodes at the basolateral membrane showed that step increases of basal potassium ([K]o) depolarized the basolateral membrane ~8 mV (n=2) and were blocked by barium. Decreasing apical [K]o mimics light-onset and hyperpolarizes the apical membrane; increasing apical [K]o depolarized the apical membrane by ~6 mV (n=3). [K]o responses were blocked by barium. The R-RPE-Ch preparation was developed to study light-induced changes in RPE physiology, and provides an in-vitro model of in-vivo function. It can be used to analyze light-evoked alterations in RPE physiology that occur in Best?s disease, which is thought to result from a mutation in basolateral membrane calcium-activated chloride channels.

RPE是一种单层色素细胞，与视网膜感光细胞相互作用，帮助维持视觉功能。我们开发了一种新的制备方法来研究大鼠RPE生理学，包括神经视网膜。将视网膜-视网膜色素上皮-脉络膜（R-RPE-Ch）制备物置于Ussing腔中，允许视网膜和脉络膜液独立灌注。完整单层膜的平均（+/- SD）传上皮电位为4.3 +/- 1.0 mV，总传上皮电阻为152 +/- 37 ohm*cm^2 （n =10）。与其他哺乳动物RPE制剂一样，我们在根尖和基底外膜上发现了钡敏感的K通道。基底膜上的细胞内微电极显示，基底钾（[K]o）的阶跃增加使基底膜去极化~8 mV (n=2)，并被钡阻断。减少的根尖[K]o模拟起光并使根尖膜超极化；增加根尖[K]o使根尖膜去极化~6 mV （n=3）。[K]没有反应被钡阻断。R-RPE-Ch的制备是为了研究光诱导的RPE生理变化，并提供了一个体内功能的体外模型。它可以用来分析光诱发的RPE生理变化，这些变化发生在Best？S病，被认为是由基底外侧膜钙激活的氯离子通道突变引起的。