PRESSURE AND FLOW IN THE RETINAL CIRCULATION

视网膜微血管疾病在许多疾病中都很重要。 这会损害视力。视网膜血流已被广泛研究， 然而，视网膜血管压力决定了两者的毛细血管 灌流和过滤压力，还没有直接测量。 这项建议中描述的实验利用了新开发的 微穿刺术研究微血管的控制 血压和视网膜中的流量。伺服微穿刺术 使用微吸管测量流体静力的技术 压力，将被用来测量完整视网膜的血管压力 一只被麻醉的猫。 该提案分为几个部分，其中有相当大的重叠 实验技术和科学目的。在第一部分，压力 在视网膜血管下将测定几种生理状态 与自动调节机制相关的条件。条件 将接受测试的包括改变的血气紧张和 高血糖症。在第二部分，我们注意到我们对 视网膜静脉压与目前对视网膜的认识相矛盾 我们对我们的数据提出了两种可能的解释 提出实验来检验我们的假设。在第三部分，影响 一种新的基于氟碳的替代品，这可能被证明是有用的 一种治疗视网膜血管阻塞的方法，将测试其效果 微血管压力和血流量。在第四部分中，我们将使用我们的 新近发展的视网膜血管阻塞模型 视网膜血栓形成对视网膜微血管压的影响。 这些研究有望阐明以下几种疾病的病因 有循环成分的疾病，包括糖尿病、青光眼、 视网膜水肿和视网膜阻塞性疾病。 猫将成为所有这些研究的首选动物，因为 它的视网膜和视网膜血管系统与中国人的比较相似 人类。

Disorders of the retinal microvasculature are important in many diseases which impair vision. Retinal blood flow has been studied extensively, however retinal vascular pressures, which determine both capillary perfusion and filtration pressures, have not been directly measured. The experiments described in this proposal make use of newly developed micropuncture techniques to investigate the control of microvascular blood pressure and flow in the retina. The servonull micropuncture technique, in which micropipettes are used to measure hydrostatic pressure, will be used to measure vascular pressures in the intact retina of an anesthetized cat. The proposal is divided into several parts with considerable overlap in experimental technique and scientific purpose. In part one, pressures in retinal vessels will be determined under several physiological conditions which are related to autoregulatory mechanisms. Conditions to be tested include the effects of altered blood gas tensions and hyperglycemia. In part two, we note that our preliminary studies of retinal vein pressure contradict current understanding of retinal hemodynamics and we present two possible explanations for our data and propose experiments to test our hypotheses. In part three, the effect of a new fluorocarbon-based substitute, which may prove to be useful as a treatment for retinal vascular occlusion, will be tested for its effect on microvascular pressures and flow. In part four, we will use our recently developed model of retinal vascular occlusion to assess the effects of a retinal thrombosis on retinal microvascular pressures. These studies are expected to shed light on the etiology of several diseases which have circulatory components including diabetes, glaucoma, retinal edema and retinal occlusive disease. The cat will be the animal of choice for all these studies because of the comparative similarity of its retina and retinal vasculature to those of humans.