BREATHING STRATEGY

呼吸泵是一种坚固的多肌肉泵。各种不同的行为 呼吸肌是高度冗余的，并提供维持 在广泛的条件下通风。四足动物，安静 呼吸是通过协调激活各种不同的 呼吸肌，包括那些经典被认为是 无声的，呼气的肌肉。不同呼吸系统的协调 肌肉是产生有效和高效的移位的关键 胸壁结构。在麻醉动物中，产生 膜片的机械效率的降低与 随着呼气相的活跃程度的增加。 在这种情况下，呼气肌对维持 通风。在安静的时候，呼气的活跃性质也存在 容易清醒的动物的呼吸，尽管它们对减少呼吸的反应 吸气肌的效率还没有被解决。研究的目标是 提案中概述的是确定使用、协调和 清醒动物呼吸肌的机械偶联 调查在不同环境下维持通风的策略 横隔膜缩小的生理和病理生理条件 效率。 我们假设清醒四足动物的吸气和呼气肌肉 在维持潮气量方面发挥协同作用。更多 具体地说，我们假设在吸气肌减少的状态下 在清醒状态下保持效率、通风和足够的气体交换 动物通过呼气肌肉系统施加的增强作用。 吸气肌的效率会急剧下降。 姿势的改变(特定目标A)和长期服用木瓜酶- 诱发肺气肿(特定目标B)。为了检验上述假设，我们将 1)评估各种呼吸泵的激活和协调情况 清醒自主呼吸犬的肌肉，2)评估活跃的和 激活和协调之间的被动机械后果 各种肌肉，3)评估肌肉的功能作用 潮汐发生时的吸气/呼气时相 容量，以及4)评估呼吸泵的工作长度 清醒动物的肌肉以其产生最适力的长度为索引。 激活事件(肌电和血流)和机械性事件的描述 事件(肌肉长度的变化、体积移位)被视为 在开发呼吸肌功能和呼吸功能的分析方面 协调。因为肌肉相互作用的影响仍然在很大程度上 未知，本提案中概述的研究应提供新的 关于呼吸泵肌肉功能组织的信息 以及它们在健康和疾病方面的整合。

The respiratory pump is a robust multi-muscle pump. The actions of various respiratory muscles are highly redundant and provide the means to maintain ventilation under a wide range of conditions. In quadrupeds, quiet breathing is accomplished by the coordinated activation of various respiratory muscles, including those classically considered as being silent, the expiratory muscles. Coordination of the different respiratory muscles is crucial in producing effective and efficient displacements of chest wall structures. In anesthetized animals, conditions producing reductions in the mechanical efficiency of the diaphragm are associated with increases in the active nature of the expiratory phase of breathing. Under these conditions, the expiratory muscles are critical in maintaining ventilation. The active nature of expiration is also present during quiet breathing in awake prone animals, although their response to reduction in inspiratory muscle efficiency have not been addressed. The goal of studies outlined in the proposal is to determine the use, coordination, and mechanical coupling of respiratory muscles in awake animals and to investigate the strategies employed in maintaining ventilation in various physiological and pathophysiological conditions of reduced diaphragm efficiency. We hypothesize that inspiratory and expiratory muscles in awake quadrupeds function synergistically in the maintenance of tidal volume. More specifically, we hypothesize that in states of reduced inspiratory muscle efficiency, ventilation and adequate gas exchange are maintained in awake animals through an augmented role exerted by the expiratory musculature. Reduced inspiratory muscle efficiency will be produced acutely following changes in posture (Specific Aim A) and chronically following papain- induced emphysema (Specific Aim B). To test the above hypothesis, we will 1) assess the activation and coordination of various respiratory pump muscles in awake spontaneously breathing dogs, 2) assess the active and passive mechanical consequences of the activation and coordination between the various muscles, 3) assess the functional role of the inspiratory/expiratory phase of breathing in the generation of tidal volume, and 4) assess the operational lengths of the respiratory pump muscles in awake animals indexed to their optimal force producing length. Descriptions of activation events (EMG and blood flows) and mechanical events (change in muscle length, volume displacements) are viewed as complimentary in developing an analysis of respiratory muscle function and coordination. Because the effects of muscle interactions are still largely unknown, the studies outlined in this proposal should provide new information on the functional organization of the respiratory pump muscles and on their integration in health and in disease.