BREATHING STRATEGY

呼吸策略

• 批准号: 2221219
• 负责人: GASPAR Andrew FARKAS
• 金额: $ 6.03万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 1995-01-25
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2221219
• 关键词: biomechanics; disease /disorder model; dogs; electromyography; emphysema; muscle contraction; posture; respiratory airway volume; respiratory muscles

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.

呼吸泵是一个强大的多肌肉泵。各种行动 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 呼吸肌，包括那些传统上被认为是 安静的呼气肌不同呼吸道的协调 肌肉在产生有效和高效的位移中至关重要， 胸壁结构在麻醉的动物中， 隔膜机械效率的降低与 随着呼吸的呼气阶段的主动性质的增加。 在这种情况下，呼气肌在维持 通风.呼气的主动性在安静时也存在 在清醒的动物中呼吸，尽管他们对减少呼吸的反应是， 吸气肌效率尚未得到解决。学习的目标 建议中概述的是确定使用，协调， 机械耦合的呼吸肌在清醒的动物和 调查在维持通风的各种策略， 膈肌缩小的生理和病理生理条件 效率 我们假设清醒的四足动物的吸气和呼气肌肉 在维持潮气量方面协同作用。更 具体来说，我们假设在吸气肌减少的状态下， 在清醒状态下维持效率、通风和充分的气体交换 动物通过呼气肌肉组织所发挥的增强作用。 吸气肌效率的降低将在以下情况下急剧产生： 姿势变化（特定目标A）和长期服用木瓜蛋白酶- 诱发肺气肿（特定目标B）。为了验证上述假设，我们将 1)评估各种呼吸泵的激活和协调 在清醒的自主呼吸狗的肌肉，2）评估活动和 被动的机械后果之间的激活和协调 各种肌肉，3）评估的功能作用， 在产生潮气时呼吸的吸气/呼气阶段 容积，以及4）评估呼吸泵的操作长度 在清醒的动物的肌肉索引到他们的最佳力量产生长度。 激活事件（EMG和血流）和机械的描述 事件（肌肉长度的变化，体积位移）被视为 在开发呼吸肌功能分析方面具有互补性， 协同因为肌肉相互作用的影响在很大程度上 未知，这项建议中概述的研究应该提供新的 关于呼吸泵肌功能组织的信息 以及它们在健康和疾病中的整合。