PREVENTION OF INCREASED VASCULAR PERMEABILITY

β-肾上腺素能激动剂已被证明可以减轻水肿， 增加的血管通透性，各种药物可在全身 和肺血管床。 更新的目标是：（1） 确定β-受体激动剂是否通过直接作用减少水和蛋白质通量 对水和白蛋白的内皮渗透性的影响和/或通过改变 （2）确定β-受体激动剂作为潜在的有效性 用于肺水肿和血管通透性增加的治疗剂， 以及（3）确定从刺激腺苷酸环化酶到 细胞骨架和连接组织，用于增强屏障 内皮的功能。 我们假设β-受体激动剂，尤其是 当作为气雾剂给药时，可以防止或减少液体增加， 血液动力学、气体交换和 肺顺应性 我们还假设，这些代理修改渗透性 通过它们对连接相关微丝的作用， 连接结构、细胞形状和渗透性的改变。 的 本次更新的总体设计采用了结构-功能方法， 细胞培养模型、离体器官模型和整个动物模型。 这些模型 重点关注肺内皮，并利用白蛋白摄取作为常见的 蛋白质渗透性指标。 毛细管压力的测量， 水力传导率、扩散白蛋白通量和白蛋白反射 将使用离体灌注豚鼠肺中的系数来 区分血流动力学和β- 通过循环或气道给药的激动剂。 测量 肌醇磷酸代谢和胞质钙将被制造， 确定β-受体激动剂是否影响这些过程， α-凝血酶的渗透性增加作用。 羊会习惯 确定β-受体激动剂是否是肺部疾病的潜在治疗药物 水肿和血管通透性增加，后者由 反射系数的计算。 研究将比较 静脉内与气道给药的药物对液体和蛋白质 流量、血液动力学、气体交换和肺顺应性。 内皮细胞 从牛肺动脉内皮细胞培养的单层将被 用于继续确定渗透性的机制- 降低β-激动剂的作用。 用于激活或抑制 膜环化酶和激酶也将决定cAMP的作用是否是 cGMP增强剂共享。 相关的光，免疫荧光， 电子显微镜可以确定β-受体激动剂是否会增加 以及肌动蛋白微丝的外周带与 内皮细胞的连接元件，从而防止 内皮连接、细胞形状和通透性的改变 由α-凝血酶诱导 与这些目标并行的是长期的- 长期目标是确定跨细胞信号通路， 改变内皮细胞和上皮细胞的形状， 起到半透膜的作用。

Beta-adrenergic agonists have been shown to attenuate the edema and increased vascular permeability that various agents can produce in systemic and pulmonary vascular beds. The objectives of this renewal are to: (1) determine if beta-agonists reduce water and protein fluxes by a direct effect on endothelial permeability of water and albumin and/or by changes in hemodynamics; (2) determine the validity of beta-agonists as potential therapeutic agents for pulmonary edema and increased vascular permeability, and (3) determine the mechanism, from stimulation of adenylate cyclase to cytoskeletal and junctional organization, for enhancement of the barrier function of the endothelium. We hypothesize that beta-agonists, especially when administered as an aerosol, can prevent or reduce increased fluid and protein fluxes with minimal alterations in hemodynamics, gas exchange, and lung compliance. We also hypothesize that these agents modify permeability by their action on junctional associated microfilaments to prevent alterations in junctional architecture, cell shape, and permeability. The overall design of this renewal utilizes a structure-function approach and models of cell culture, isolated organ, and whole animal. These models focus on the pulmonary endothelium and utilize albumin uptake as the common indicator of protein permeability. Measurements of capillary pressure, hydraulic conductivity, diffusive albumin flux, and the albumin reflection coefficient in the isolated, perfused guinea pig lung will be used to differentiate between hemodynamic and direct permeability effects of beta- agonists administered via the circulation or airway. Measurements of inositol phosphate metabolism and cytosolic calcium will be made to determine if beta-agonists affect these processes in opposition to the permeability - increasing action of alpha-thrombin. Sheep will be used to determine if beta-agonists are potential therapeutic agents for pulmonary edema and increased vascular permeability, the latter assessed by the calculation of the reflection coefficient. Studies will compare intravenous versus airway administration of the agents on fluid and protein fluxes, hemodynamics, gas exchange, and lung compliance. Endothelial cell monolayers cultured from bovine pulmonary artery endothelial cells will be used to continue to determine the mechanism for the permeability - decreasing action of beta-agonists. Drugs designed to activate or inhibit membrane cyclases and kinases will also determine if the action of cAMP is shared by cGMP-enhancing agents. Correlative light, immunofluorescence, and electron microscopy will determine if beta-agonists increase the number and interaction of the peripheral band of actin microfilaments with junctional elements of endothelial cells and, thereby, prevent the alterations in the endothelial junction, in cell shape, and in permeability induced by alpha-thrombin. In parallel with these objectives is the long- term goal of determining the transcellular signalling pathways that may alter the shape of endothelial and epithelial cells to influence their function as semipermeable membranes.