CONTROL OF BREATHING DURING PHYSIOLOGIC CONDITIONS

生理条件下呼吸的控制

• 批准号: 3338221
• 负责人: HUBERT V FORSTER
• 金额: $ 9.89万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-06-01 至 1991-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3338221
• 关键词: acid base balance; afferent nerve; blood pressure; blood volume; body temperature regulation; brain metabolism; carbon dioxide; cardiac output; carotid body; cerebrospinal fluid; chemoreceptors; denervation; dogs; electroencephalography; electromyography; environmental stressor; erythrocytes; exercise; heart rate; horses; hyperpnea; hypoxia; neural plasticity; norepinephrine; oxygen transport; positive pressure breathing; pulmonary respiration; respiration regulatory center; respiratory gas; respiratory muscles; respiratory oxygen; respiratory reflex; serum; sleep; spinal cord surgery; urine; vagus nerve

Our major objective is to enhance understanding of the control of breathing. A related objective is to gain insight into mechanisms which determine O2 transport during exercise. The 1st specific aim is to determine whether afferents from exercising limbs are critical to the exercise hyperpnea. In pilot studies under anesthesia, the ventilatory (V-E) response to electrically induced exercise was attenuated by lesioning the dorsal lateral sulcus (DLS) & dorsal lateral funiculus (DLF) spinal pathways at the L2 level. Except for the 1st of 4 dogs & the 1st of 2 ponies, lesioning did not compromise ambulation. Accordingly, during treadmill exercise, V-E and blood gases will be studied in 8 awake ponies before and 2-4 weeks after DLS and DLF lesions or sham surgery. A 2nd aim is to determine whether spinal lesioning in carotid body denervated (CBD), hilar nerve denervated (HND), and CBD+HND ponies affects the exercise hyperpnea differently than spinal lesions alone. Studies before and after multiple lesions are a means of testing the hypothesis that multiple mechanisms are capable of mediating the exercise hyperpnea, and therefore the hyperpnea may not be attenuated unless most or all mechanisms are eliminated. A 3rd aim is to test the hypothesis that breathing periodicity at high altitude is due to the increased carotid chemoreceptor gain due to hypoxia combined with the hypocapnia-induced apnea threshold. Breathing, blood gases, and EEG will be monitored in 8 ponies before and after CBD or sham CBD in awake and sleeping states at sea level and during 3 days of hypobaria (PaO2 = 40 mmHg). A 4th aim is to determine whether upper airway, lung, or carotid sensory mechanisms alter respiratory neural output to defend tidal volume when inspiratory muscle length is altered to an unfavorable portion of the length-tension curve. V-E, blood gases, and respiratory muscle EMG will be studied in normal, CBD, HND, and tracheostomized ponies before and during positive pressure breathing (+10CM H2O) which increases lung volume and alters muscle length. A 5th aim is to determine whether the 25% overshoots in heart rate and cardiac output of ponies in the 1st min of work are due to mobilization of splenic erythrocytes or peripheral afferent information. These responses will thus be studied before and after DLS and DLF spinal lesions and in other ponies before and after splenectomy. The pony is a proven model for chronic studies requiring maintenance of physiologic conditions. Accordingly, use of the awake pony provides unique tests of theoretical models and hypotheses developed using other species under conditions of anesthesia.

我们的主要目标是提高对控制 呼吸了 一个相关的目标是深入了解 在运动过程中确定O2运输。 第一个具体目标是 确定来自运动肢体的传入神经是否对 运动性呼吸过度。 在麻醉下的初步研究中， (V-E)对电诱导运动的反应通过损伤而减弱 背外侧沟（DLS）和背外侧索（DLF）脊髓 在L2水平的路径。 除了四只狗中的第一只和两只狗中的第一只 小马，病变并没有损害ampergum。 因此，在 将在8匹清醒的小马中研究跑步机运动、V-E和血气 在DLS和DLF病变或假手术之前和之后2-4周。 第二个目标 是为了确定颈动脉体失神经支配（CBD）的脊髓病变， 门神经失神经支配（HND），CBD+HND小马影响运动 呼吸过度不同于单独的脊柱病变。 研究前后 多处病变是检验多处病变 机制能够介导运动呼吸过度，因此 呼吸过度可能不会减弱，除非大多数或所有机制都 淘汰 第三个目的是检验呼吸周期性 在高海拔是由于增加颈动脉化学感受器增益， 缺氧结合低碳酸血症诱导的呼吸暂停阈值。 呼吸， 血液气体和EEG将在CBD或CBD之前和之后在8匹小马中进行监测。 在海平面的清醒和睡眠状态下，以及在3天的 低血压（PaO 2 = 40 mmHg）。 第四个目标是确定上层是否 气道、肺或颈动脉感觉机制改变呼吸神经输出 当吸气肌长度改变为 长度-张力曲线的不利部分。 V-E血气分析 呼吸肌肌电图将在正常，CBD，HND， 在正压呼吸（+10CM）之前和期间气管造口术的小马 H2O），增加肺容量并改变肌肉长度。 第五个目标是 确定心率和心输出量是否超过25%， 小马在第一分钟的工作是由于动员脾 红细胞或外周传入信息。 因此，这些反应将 在DLS和DLF脊柱病变前后以及在其他小马中进行研究 在脾切除术前后 小马是一个被证明的慢性模型 需要维持生理条件的研究。 因此，使用 提供了独特的测试理论模型， 在麻醉条件下使用其他物种开发的假设。