BASIC MECHANISMS OF RE-EXPANSION PULMONARY EDEMA

这个应用程序的总体目标是充分描述 基本的生化机制，解释了单侧的， 复发性肺水肿的通透性形式 肺部扩张。再扩张性肺水肿(RPE) 传统上被归因于扩张期间的力量 降低肺间质压并导致肺组织渗出 流体。我们的初步数据支持这样一种假设： RPE的机制涉及氧自由基介导的损伤 到肺泡毛细血管衬里细胞在快速再扩张和 先前塌陷和低灌流的肺重新充氧。 为了澄清这一机制，我们计划完成 以下具体目标：1)评估促炎因素 02代谢物(包括超氧化物和过氧化氢)在RPE中的作用 2)研究O2代谢物的酶和线粒体来源 以及细胞内的抗氧化剂，3)研究 中性粒细胞在单侧肺损伤中的作用 中性粒细胞趋化剂的分离与鉴定 在崩溃/再扩张期间。这些实验将是 使用兔的再扩张性水肿模型完成的 这些自由基探针的效果可以被测试。 细胞内的抗氧化防御，特别是线粒体超氧化物歧化酶， 将在重新扩建之前和之后进行评估。的影响 细胞外超氧化物歧化酶和过氧化氢酶 浮肿的形成将通过静脉酶来测试 前处理，脂质体包裹的SOD和CAT将 用于测试增强的细胞内抗氧化剂的效果 酶对水肿症形成的影响。其他实验将包括 以确定醛氧化酶是否是一种 该模型中超氧化物或过氧化氢的重要来源。氰化物- 不敏感的组织呼吸将被测量为肺的一个指数 自由基的形成。将对肺灌洗液进行检测 趋化活性及其细胞组成的表征 在重新扩张前后的不同时间点。学位 细胞毒性O2代谢物的产生，抗氧化剂的影响， 而化学诱导剂的产生也将在Re-Re 中性粒细胞减少兔的扩张肺，以进一步明确 中性粒细胞的贡献。这种形式的单侧肺损伤 在许多方面与成人呼吸窘迫综合征相似。它 将作为测试实验干预措施的模型 急性肺损伤，内控自肺会大大 最大限度地减少实验动物的消耗，不产生外源性 需要投放毒药。

The overall goal of this application is to fully characterize the basic biochemical mechanisms which account for the unilateral, permeability form of pulmonary edema which occurs in re- expanded lungs. Re-expansion pulmonary edema (RPE) has traditionally been attributed to forces during expansion which decrease lung interstitial pressure and lead to transudation of fluid. Our preliminary data support the hypothesis that the mechanism of RPE involves oxygen free radical-mediated injury to alveolar-capillary lining cells during rapid re-expansion and re-oxygenation of previously collapsed and hypoperfused lungs. In order to clarify this mechanism, we plan to accomplish the following specific aims: 1) assessment of the pro-inflammatory role of 02 metabolites (including superoxide and H2O2) in RPE, 2) study enzymatic and mitochondrial sources of O2 metabolites along with intracellular antioxidants, 3) investigate the contribution of neutrophils to the unilateral lung injury, and 4) isolate and characterize neutrophil chemoattractants produced during collapse/re-expansion. These experiments will be accomplished using a rabbit model of re-expansion edema in which the effects of free radical probes can be tested. Intracellular antioxidant defenses, especially mitochondrial SOD, will be assessed before and after re-expansion. The effects of extracellular superoxide dismutase (SOD) and catalase (CAT) on edema formation will be tested by intravenous enzyme pretreatment, and liposome-encapsulated SOD and CAT will be used to test the effects of augmented intracellular antioxidant enzymes on edema formation. Additional experiments will be conducted to determine whether aldehyde oxidase is an important source of superoxide or H2O2 in this model. Cyanide- insensitive tissue respiration will be measured as an index of lung free radical formation. Lung lavage fluid will be assayed for chemotactic activity and its cellular composition characterized at various time points before and after re-expansion. The degree of cytotoxic O2 metabolite production, effects of antioxidants, and generation of chemoattractants will also be measured in re- expanded lungs of neutropenic rabbits, to further specify the contribution of neutrophils. This form of unilateral lung injury resembles, in many ways, adult respiratory distress syndrome. It will serve as a model for testing experimental interventions in acute lung injury, since the internal control lung will greatly minimize consumption of experimental animals and no exogenous toxicant need be administered.