ROLE OF OXYGEN IN OCULAR PATHOLOGY

分子氧可以光产生氧的四个活化态：单态 氧、超氧阴离子、过氧化氢和羟基自由基。 尽管这些物种已被证明对 蛋白质的研究尤其局限于它们对眼睛组织的影响。 如晶状体和玻璃体。在目前的研究中，化学物质的变化 分子氧活性物种的性质和构象 玻璃体和晶状体成分(透明质酸和胶原，以及晶状体 将分别研究晶体蛋白)。光谱方法 如吸收、荧光和圆二向色性，将用于 构象研究。生物化学和水动力技术，包括 粘度、凝胶电泳法、光散射和沉淀法 平衡将被用于聚集和交联性研究。至 将特定种类的氧气的影响与 特异性的大分子、抑制剂或清道夫的构象 每一种分子氧都将被使用。 太阳光发出的近紫外光与这种现象有关。 单线态氧或其他氧的活性物种通过光动力作用 正常眼睛中存在的光敏剂。我们计划将其与 这些药物在体外系统中产生的物理化学变化 含有晶状体或玻璃体大分子成分并伴有白内障或 玻璃体液化。这项建议的长期目标是 确定玻璃体和晶状体变化的分子机制 成分，看看在光氧化和 某些眼部疾病。

Molecular oxygen can photogenerate four active states of oxygen: singlet oxygen, superoxide anion, hydrogen peroxide, and hydroxyl radical. Although these species have been shown to have damaging effects on proteins, research is particularly limited on their effects on eye tissues such as lens and vitreous. In the present study, changes in chemical properties and conformation by the active species of molecular oxygen of vitreous and lens components (hyaluronic acid and collagen, and lens crystallins, respectively) will be investigated. Spectroscopic methods such as absorption, fluorescence, and circular dichroism will be used for conformational studies. Biochemical and hydrodynamic techniques, including viscosity, gel electrophoresis, light scattering, and sedimentation equilibrium will be used for aggregation and crosslinking studies. To correlate the effect of specific species of oxygen with the change in conformation of the macromolecules, inhibitors or scavengers specific for each species of molecular oxygen will be used. Near-ultraviolet light from sunlight has been implicated in the production of singlet oxygen or other active species of oxygen by photodynamic action of the photosensitizers present in the normal eye. We plan to correlate the physicochemical changes produced by these agents in an in vitro system containing lens or vitreous macromolecular components with cataract or vitreous liquefaction. The long-term objective of this proposal is to define a molecular mechanism for the changes in vitreous and lens components and see if there may be a link between photooxidation and certain eye diseases.