Fluid Movement across Conjunctiva: Stimulation and Reg.

结膜的液体运动：刺激和调节。

• 批准号: 6814995
• 负责人: Oscar A Candia
• 金额: $ 29.66万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6814995
• 关键词: apical membrane; basolateral membrane; biological transport; conjunctiva; diffusion; electrolytes; epithelium; eye pharmacology; fluid flow; histochemistry /cytochemistry; immunocytochemistry; laboratory mouse; laboratory rat; osmosis; polymerase chain reaction; sodium; swine; water channel; western blottings

DESCRIPTION (provided by applicant): We have previously characterized the isolated rabbit conjunctiva as an epithelial model of Na absorption and CI secretion. Our hypothesis was that these transport mechanisms, by providing the driving forces for fluid movement across the tissue, could enable the conjunctiva to either absorb fluid from, or contribute fluid to, the aqueous layer of the tear film. This was demonstrated with direct experiments using the rabbit epithelium. Our current hypothesis is that the human conjunctiva may also possess transporters that enable it to absorb Na and secrete CI with the consequent fluid absorption or secretion. For this fluid flow to occur, the conjunctiva must have (as most fluid transporting epithelia do) water channels, which are usually different in the apical and basolateral domains. We thus propose to identify with biochemical and histochemical protocols, the electrolyte transporters and water channels (aquaporins) in the human conjunctiva relevant towards the movement of fluid flow across the epithelium. Because receptor-mediated responses are atypical in rabbit conjunctiva, assays similar to those in human will be done on murine and porcine tissues to determine the best model for fluid transport in the human conjunctiva. Since aquaporins (AQPs) play a crucial role in fluid transport, and our experiments have shown that anisotonic conditions and cAMP-elevating agents can modify water permeability, protocols to understand the regulation of water permeability in murine and porcine tissues will be implemented. Biochemical, histochemical and functional experiments will be conducted on mice, rat and pig conjunctivae. From the determination of the transporters, the AQPs, and the functional physiological experiments that can be done on the conjunctiva of the selected animal models, a theoretical model for the fluid movement across the human conjunctiva will be proposed. From these studies we expect to expand the understanding of the physiology of the mammalian conjunctival epithelium, and provide evidence that direct or receptor-mediated stimulation of ionic transport mechanisms will result in fluid secretion towards the tear film. These studies may provide the groundwork for the design of future treatment modalities for dry-eye syndromes.

描述（由申请人提供）：我们先前已将分离的兔结膜表征为Na吸收和Cl分泌的上皮模型。我们的假设是，这些运输机制，通过提供驱动力的流体运动通过组织，可以使结膜吸收流体，或有助于流体，泪液膜的水层。这一点在使用兔上皮的直接实验中得到了证实。我们目前的假设是，人结膜也可能具有转运蛋白，使其能够吸收Na和分泌Cl，从而吸收或分泌液体。为了使这种液体流动发生，结膜必须具有（如大多数液体运输上皮所具有的）水通道，其通常在顶侧和基底侧区域中不同。因此，我们建议，以确定与生物化学和组织化学协议，电解质转运蛋白和水通道（水通道蛋白）在人类结膜相关的液体流动的运动，通过上皮。由于受体介导的反应在兔结膜中是非典型的，因此将对鼠和猪组织进行与人体相似的试验，以确定人结膜中液体转运的最佳模型。 由于水通道蛋白（AQP）在液体转运中起着至关重要的作用，并且我们的实验表明，非等渗条件和cAMP升高剂可以改变水渗透性，因此将实施了解鼠和猪组织中水渗透性调节的方案。将对小鼠、大鼠和猪结膜进行生化、组织化学和功能实验。从确定的转运蛋白，水通道蛋白，和功能的生理实验，可以做的结膜上选择的动物模型，一个理论模型的流体运动通过人类结膜将提出。从这些研究中，我们期望扩大哺乳动物结膜上皮的生理学的理解，并提供证据表明，直接或受体介导的离子转运机制的刺激将导致液体分泌到泪膜。这些研究可能为未来干眼症治疗模式的设计提供基础。