ROLE OF OXYGEN IN OCULAR PATHOLOGY

分子氧可以光生氧的四种活性态：单线态 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人类具有破坏性影响， 蛋白质，研究特别局限于它们对眼组织的影响 例如透镜和玻璃体。 在本研究中，化学物质的变化 分子氧活性物种的性质和构象 玻璃体和透镜组分（透明质酸和胶原，以及透镜 晶体蛋白）进行研究。 光谱方法 例如吸收、荧光和圆二色性将用于 构象研究 生物化学和流体力学技术，包括 粘度、凝胶电泳、光散射和沉降 平衡将用于聚集和交联研究。 到 将特定种类的氧的影响与 大分子的构象，抑制剂或清除剂的特异性， 将使用每种分子氧。 太阳光中的近紫外线与这种物质的产生有关 通过光动力作用的单线态氧或其他活性氧种类的 存在于正常眼睛中的光敏剂。 我们计划将 这些药物在体外系统中产生的物理化学变化 含有透镜或玻璃体大分子成分的白内障患者， 玻璃体液化 这项建议的长远目标是 确定玻璃体和透镜变化的分子机制 成分，看看是否有可能是光氧化和 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.