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着重要作用。 结构。化学状态或构象的变化 NaHA或其与胶原蛋白的相互作用可改变 玻璃体，并导致液化。虽然玻璃体 液化是正常老化过程的一部分，即凝胶的损失 结构与玻璃体异常有关。 液化与玻璃体后脱离有关，后者是 各种视网膜疾病中的致病因素。玻璃体 液化也是视网膜色素变性的常见表现，高度 近视、先天性视网膜劈裂、扁平部和Wagner‘s 疾病。 这项提案的长期目标是界定 玻璃体结构中的NaHA及其结构功能 分子间的关系。该提案的具体目的 主要内容有：(1)玻璃体大分子成分的研究 包括透明质酸的构象研究，其作用机理 通过它来降解分子，以及它与 胶原蛋白。非胶原蛋白也将被表征，以及 将评估它们在玻璃体结构和功能中的作用。(2) 通过一项新开发的技术，玻璃体包括人类 (正常、老年和患病)将被研究以确定 透明质酸、胶原和非胶原蛋白 组织的结构完整性。(3)牛的液化 玻璃体将由光动力或酶反应诱导 并将评估玻璃体抗坏血酸的保护作用。 我们将使用荧光染料和高碘酸氧化作为探针， 研究Naha的构象方面。研究其作用机制 对于NaHA的降解，我们将使用酶法， 非酶和光动力产生的自由基物种 与NaHA反应；然后我们将从结构上研究该分子结构。 圆二色、荧光与高效液体 将使用层析法对分子进行研究 那霸的性质。

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.