Interactions of body temperatures and modulators of human pulmonary ventilation

运动通气的控制机制在人体生理学中仍然是一种异常现象。许多关于该控制系统功能的假设无法完全解释在剧烈运动期间肺通气相对于代谢需求的不成比例的增加。我们假设在运动过程中，核心温度（Tc）是一个显着的影响肺通气。 支持这一新观点的证据来自我们对被动（即休息时热浸）和主动加温（即运动）人体肺通气的Tc阈值的证明，以及在更明显的高热期间Tc与肺通气之间的比例关系。 这种比例关系表明了一种因果关系，这得到了我们进一步研究的支持，表明Tc和已知的肺通气调节剂（即动脉PCO 2/pH和PO 2）之间存在积极的相互作用。 一种新兴的观点认为，升高的Tc刺激通气，当热调节优先于化学调节时，这随后是第二阶段或残余喘息反应。本研究的目的是进一步探讨高血压引起的过度通气的本质和机制。 为了实现这一目标，我们将评估如何调节通气和Tc相互作用的影响，热疗期间的热和化学调节。 将采用逐呼吸潮气末强制系统，以夹持潮气末二氧化碳和氧气的分压。这项研究的新奇和意义将有助于解决长期存在的人类如何以及为什么过度运动的异常现象。 阐明通气和温度调节剂如何在热调节和化学调节中相互作用，将有助于拓宽对人类这两个生理控制系统功能的理解。

Mechanisms underlying the control of exercise ventilation remain an anomaly in human physiology. Numerous hypotheses on the function of this control system are unable to fully explain the disproportionate increases in pulmonary ventilation relative to metabolic needs during intense exercise. We hypothesized that during exercise core temperature (Tc) is a significant influence on pulmonary ventilation. Evidence supporting this novel view was from our demonstration of Tc thresholds for pulmonary ventilation in both passively (i.e. hot immersion at rest) and actively warmed (i.e. exercise) humans and proportional relationships between Tc and pulmonary ventilation during more pronounced hyperthermia. This proportionality suggested a causal relationship that was supported by our further studies that indicated positive interactions between Tc and known modulators (i.e. arterial PCO2/pH & PO2) of pulmonary ventilation. An emerging view became that elevated Tc stimulates ventilation and this is followed by a second phase or vestigial panting response when thermo- is prioritized over chemo-regulation. The objective of the proposed research is to further explore the nature and mechanisms underlying this hyperthermia-induced hyperventilation. To attain this objective we will assess how modulators of ventilation and Tc interact in their influences on thermo- and chemo- regulation during hyperthermia. A breath-by-breath end-tidal forcing system will be employed to allow clamping of partial pressures of end-tidal carbon dioxide and oxygen. The novelty and significance of this research will be to contribute to the resolution the long-standing anomaly of how and why humans hyperventilate heavy exercise. Elucidating how modulators of ventilation and temperature interact in thermo- and chemo- regulation of will help broaden the understanding of the function of these two physiological control systems in humans.