ENVIRONMENTAL LIGHT AND RETINAL MEMBRANE DEVELOPMENT

环境光与视网膜膜发育

• 批准号: 3256368
• 负责人: DANIEL T ORGANISCIAK
• 金额: $ 17.22万
• 依托单位: WRIGHT STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-04-01 至 1994-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3256368
• 关键词: DNA; antioxidants; ascorbate; cell death; chromatography; congenital vision disorder; electron microscopy; fatty acids; gene expression; histology; laboratory rat; light adaptations; light adverse effect; membrane lipids; membrane proteins; membrane structure; microscopy; monoclonal antibody; radioassay; retina degeneration; retinal pigment epithelium; retinaldehyde; rhodopsin; rod cell; transducin; unsaturated fatty acids; visual photoreceptor; visual photosensitivity

Studies are proposed to continue and extend findings relevant to the pathological effects of visible light in the eye and the mechanisms by which protective agents such as ascorbic acid reduce or prevent light damage. We will study different forms of retinal light damage, involving primarily degeneration of the visual cells, or damage to both the visual cells and the associated retinal pigment epithelium (RPE). Our long term goal is to understand the mechanism of light damage in the rat and, from the insights we gain, to extend our findings to other species. These studies are seen as being relevant to the prevention of light damage in the human eye, especially during periods of intense light exposure as may occur in the clinical, surgical or work-place environments and from the long term-cumulative effects of light in the eye. The protective effects of ascorbic acid administration and dietarily reduced levels of rod outer segment (ROS) docosahexaenoic acid will be studied separately, or in combination under conditions which accelerate and exacerbate different forms of light damage and during early discrete periods of light exposure to identify causative factors of damage. Reversible and irreversible effects of light will be determined by measuring rhodopsin and visual cell DNA, peroxidative metabolites of fatty acids and ERG changes in the retinas of rats. Retinol and enzyme measurements will be made to assess the effects of light's toxic action on the RPE and ROS membranes, in combination with collaborative histological evaluation. Monoclonal antibody based methods will be used to determine adaptive changes in the intracellular visual cell proteins transducin and S-antigen that may alter the form and extent of light damage in developing and adult rats. In general, the specific aims of our proposal are: (1) To determine the kinetics of the retinal uptake of D- and L-ascorbate following injection by different routes and to correlate the severity of damage with the concentration of ascorbate in the retina and RPE. (2) To correlate the magnitude of ROS degeneration, rod cell death and RPE degeneration as produced by intermittent light exposure with ROS polyunsaturated fatty acids and to isolate oxidative metabolites of labeled ROS fatty acids. (3) To measure the levels of rhodopsin, S-antigen and transducin in relation to long-term adaptive states in the retina and the expression of the rdy mutation, and to relate their levels to the light history dependent and age-related susceptibility of rats to damage from continuous or intermittent light exposure.

建议继续进行研究，并扩大与以下方面相关的发现 可见光对眼睛和眼睛的病理影响 抗坏血酸等保护剂降低 或防止光线伤害。我们将研究不同形式的视网膜 光损伤，主要涉及视觉细胞的退化， 或对视觉细胞和相关的视网膜造成损害 色素上皮(RPE)。我们的长期目标是了解 大鼠的光损伤机制，从我们的洞察力来看， 收益，将我们的发现扩展到其他物种。这些研究是 被视为与预防光损害有关 人眼，尤指在强光照射期间，如 可能发生在临床、外科或工作场所环境中， 来自长期累积的光线在眼睛中的影响。这个 服用抗坏血酸对饮食的保护作用 降低杆状外段(ROS)二十二碳六烯酸的水平将 可以单独研究，也可以在下列条件下结合研究 加速和加剧不同形式的光损害和 在早期离散的光暴露期间识别 造成损害的原因。可逆和不可逆效应 将通过测量视紫红质和视觉细胞来确定光的数量 DNA、脂肪酸过氧化代谢产物与视网膜电图的变化 大鼠的视网膜。视黄醇和酶的测定将进行 评估光对RPE和ROS的毒性作用 膜与协作组织学相结合 评估。基于单抗的方法将用于 确定细胞内视觉细胞的适应性变化 转导蛋白和S-抗原，可能改变形式和 发育和成年大鼠的光损伤程度。总体而言, 我们建议的具体目标是：(1)确定 D-和L-抗坏血酸在视网膜中的摄取动力学 通过不同的途径注射，并相互关联严重程度 损伤与视网膜和RPE中抗坏血酸的浓度有关。 (2)ROS变性程度与视杆细胞死亡之间的关系 以及由间歇性光照引起的RPE变性 与ROS多不饱和脂肪酸和分离氧化 标记ROS脂肪酸的代谢物。(3)衡量水平 视紫红质、S抗原和转导蛋白的长期相关性 视网膜适应状态与Rdy的表达 突变，并将它们的水平与依赖于光历史的 和与年龄相关的大鼠对持续性损伤的易感性 或者间歇性光照。