VOLUME REGULATION IN CORNEAL ENDOTHELIUM

细胞体积的维持是一个在所有动物身上表达的动态平衡过程 细胞。必要的水在质膜上的运动是耦合的。 以解决也涉及到其他细胞的运输机制 葡萄糖的积累、phi调节或载体等活动 流体运输。角膜内皮细胞被赋予一种活性离子 负责向量流体传输的泵机构，因此 维持角膜水化，这是角膜透明度的决定因素。 由于这种流体传输和细胞体积调节必须交织在一起， 必须建立量的维护和管理机制 规则，以获得对流体传输的完整了解。在……里面 此外，了解体液如何转运具有临床意义。 在渗透应激期间会受到影响，例如在戴隐形眼镜期间 还有糖尿病。这项研究的重点是建立 对导致空头的急性和持续扰动的成交量调节 和长期成交量分别调整/短期成交量 将通过以下方式研究调节：细胞体积和 确定细胞内离子活性的机制和第二 有信使参与。实验将采用非等渗微扰， 酸中毒、缺氧、离子置换和转运特异性抑制物。 将在适应的范围内审查长期的音量调节 通过调节有机渗透分子的水平来维持非渗透负荷 (如氨基酸、肌醇和山梨醇)。体外分离的兔 角膜和培养的牛内皮细胞融合在一起 将使用在玻璃套上或透气支架上极化的材料。 细胞体积的动态将用灵敏的光来测量。 散射技术和通过跟踪荧光的浓度 用作音量标记的染料。这项研究的长期目标是 了解流体运输、phi调节和 正常状态下角膜内皮细胞的容量调节活性 在代谢应激状态下，高血糖和不等渗症 大把的。

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.