HYALURONIC ACID IN THE NORMAL AGED & DISEASED VITREOUS

透明质酸钠（NaHA），一种大分子成分， 玻璃体，在稳定凝胶玻璃体中起重要作用 结构 化学状态或构象的变化 NaHA或其与胶原的相互作用可以改变凝胶状态， 导致玻璃体液化。 虽然玻璃 液化是正常老化过程的一部分， 结构与玻璃体异常相关。 液化与玻璃体后脱离有关， 各种视网膜疾病的致病因素。 玻璃体 液化在视网膜色素变性中也是常见的， 近视、先天性视网膜劈裂、睫状体平坦部炎和瓦格纳 疾病 这项建议的长期目标是界定 玻璃体结构中的NaHA及其结构-功能 分子的关系。 提案的具体目标 （1）玻璃体大分子组成的研究 包括透明质酸的构象研究， 分子被降解， 胶原 非胶原蛋白也将被表征， 将评估它们在玻璃体结构和功能中的作用。 （二） 利用新开发的技术， （正常，老年和患病）将被研究，以确定的作用， 透明质酸、胶原和非胶原蛋白 组织的结构完整性。 (3)牛液化 玻璃体将通过光动力学或酶促反应诱导 并评估玻璃状抗坏血酸的保护作用。 我们将使用荧光染料和高碘酸盐氧化作为探针， 研究NaHA的构象方面。 可能机制 的NaHA降解，我们将使用酶， 非酶促和光动力学产生的自由基物种 与NaHA反应;然后我们将研究分子结构。 圆二色性、荧光性和高性能液体 色谱法将被用来研究分子 NaHA的特性

Sodium hyaluronate (NaHA), a macromolecular component of the vitreous, plays an important role in stabilizing the gel vitreous structure. Changes in the chemical state or conformation of NaHA or its interaction with collagen could alter the gel state of the vitreous and result in liquefaction. Although vitreous liequefaction is part of the normal aging process, the loss of gel structure has been correlated with vitreous abnormalities. Liquefaction is related to posterior vitreous detachment which is a pathogenetic factor in various retinal disorders. Vitreous liquefaction is also a frequent finding in retinitis pigmentosa, high myopia, congenital retinoschisis, pars planitis, and Wagner's disease. The long-term objective of this proposal is to define the role of NaHA in the vitreous structure and the structure-function relationship of the molecular. The specific aims of the proposal are: (1) Study of the macromolecular components of the vitreous including conformational studies of hyaluronate, the mechanism by which the molecule is degraded, and its interaction with collagen. Noncollagenous proteins will also be characterized, and their role in vitreous structure and function will be assessed. (2) With a newly developed technique, vitreous including human (normal, aged, and diseased) will be studied to define the role of hyaluronate, collagen, and noncollagenous proteins in the structural integrity of the tissue. (3) Liquefaction of bovine vitreous will be induced by photodynamic or enzymatic reaction and the protective role of vitreous ascorbic acid will be assessed. We will use fluorescent dye and periodate oxidation as probes to study conformational aspects of NaHA. To study the mechanism of NaHA degradation, we will use enzymatically, nonenzymatically, and photodynamically generated radical species to react with NaHA; we will then study the molecule structurally. Circular dichroism, fluorescence and high-performance liquid chromatography will be employed to study the molecular properties of NaHA.