EFFECT OF PNEUMONECTOMY AND EXERCISE ON LUNG GROWTH

我们的目标是确定成熟肺的适应潜力 广泛肺切除术（即肺切除术）后， 结构-功能方法 有两种补偿机制 肺切除术后剩余肺：1）更多地利用 现有的生理储备（募集），和2）新肺的生长。 我们的具体目标是确定的限制和功能的重要性， 各机制在整体功能补偿中的作用。 这些问题的答案对于理解 适应在成熟的肺;他们有广泛的基本生理和 优化肺切除术后处理的临床意义 切除术 将输入16只同窝和性别匹配的幼犬（2月龄） 分为两组。 一半的狗将接受右肺切除术。 另 其中一半将接受假肺切除术。 他们将同时被提升 直到完全长大（14个月大），并将保持运动训练后， 手术直至处死。 将评估功能补偿率 在成熟过程中，通过连续测量肺弥散量及其 成分，最大耗氧量，肺容量，压力-容量 关系和工作的呼吸在休息和在不同的工作量了 最大限度的锻炼。 在达到成熟后， 补偿将通过类似的测量和研究进行评估， 血液动力学和气体交换。 在得到 成熟时的生理数据，将动物处死，并测量肺部 原位固定用于详细的形态测定分析。 通过比较结果评估生理募集的程度 在相同的工作量下进行分组。 采用系统方法， 将生理扩散能力解释为 肺血流量和肺容量。 结果与 从同一动物的形态测量数据计算的弥散能力。 将评估肺切除术后肺生长的范围和来源 通过形态计量学测量肺泡表面积、 肺泡的成分和每种类型细胞的数量。

Our objective is to define the adaptive potential of the maturing lung after extensive lung resection (i.e. pneumonectomy) using an integrated structure-function approach. Two mechanisms of compensation are available to the remaining lung after pneumonectomy: 1) greater utilization of existing physiologic reserves (recruitment), and 2) growth of new lung. Our specific aims are to define the limits and functional significance of each mechanism in the overall functional compensation. Answers to these questions are important in understanding the limits of adaptation in the maturing lung; they have broad basic physiological and clinical significance in the optimal management of patients undergoing lung resections. Sixteen litter and sex matched puppies (2 months of age) will be entered into 2 groups. Half the dogs will undergo right pneumonectomy. The other half will undergo sham pneumonectomy. They will be raised simultaneously until full grown (14 months of age) and will be kept exercise trained after surgery until sacrifice. Rates of functional compensation will be assessed during maturation by serial measurements of lung diffusing capacity and its components, maximal O2 consumption, lung volume, pressure-volume relationships and work of breathing at rest and at different workloads up to maximal exercise. After reaching maturity, the ultimate extent of compensation will be assessed by similar measurements plus studies of hemodynamics and gas exchange during heavy exercise. After obtaining physiologic data at maturity, the animals are sacrificed and the lungs fixed in situ for detailed morphometric analysis. The extent of physiologic recruitment is assessed by comparison of results between groups at the same workload. A systematic approach is used to interpret physiologic diffusing capacities as functions of changes in pulmonary blood flow and lung volume. Results are correlated with diffusing capacities calculated from morphometric data in the same animal. The extent and sources of lung growth after pneumonectomy will be assessed by morphometric measurements of alveolar surface area, volume densities of components of the alveoli and number of each type of cells.