Control of Human Breathing in Extreme Environments

与许多喘息降温的小型哺乳动物不同，人类将体表出汗作为热量散失的主要效应器。这可能令人惊讶，但人类的呼吸也会对体温的变化做出反应。在炎热的天气中，两种反应都很明显，而在寒冷的天气中，明显的喘息反应是一种特有的反应。我的研究计划的主要目标是建立人体体温变化后控制人类呼吸的机制。我的研究假设是，体温的高低会对人类的呼吸产生重要的刺激作用。 我的研究项目最近在三个方面取得了进展。在第一个领域，我们研究了体温升高的人类对二氧化碳和氧气这两种呼吸性气体的化学输入的反应。我们证实，体温升高与这两种呼吸气体单独或协同作用，控制人类的呼吸。在第二个领域，我们构思、建造并验证了一种新型的逐次呼吸装置，用于精确控制这两种呼吸气体。在第三个区域，与其他人类体温调节热损失反应类似，我们揭示了人类在反复热应激后的热喘息反应的适应。 在拟议的研究计划中，我们将在两个研究领域使用我们的新型呼吸气体控制系统。在第一个领域，我们将确定在急性和反复体温下降期间控制人类喘息反应的机制。在第二个领域，我们将确定人类的热喘息反应如何有助于控制血压，在加拿大老年人中，我们将评估这种人类热喘息是否适应反复的热应激。 这项研究对所有加拿大人的好处是提高了我们对人类在极端气候中生活的能力的理解，这种极端气候在我们国家全球变暖的情况下越来越明显。

Unlike many small mammals that pant to cool their bodies, humans employ surface sweating as the main effector for heat loss. It may be surprising but human breathing also responds changes in body temperatures. Both a thermal panting response is evident in the heat and a pronounced gasp response is a characteristic response in the cold. The primary objective of my research program is to establish the mechanisms of control of human breathing after changes in body temperature. My research hypothesis is that high or low body temperatures provide an important stimulus to human breathing. Recent progress in my research program is in three areas. In the first area, we examined how humans with elevated body temperatures responded to the chemical inputs from the two respiratory gases, carbon dioxide and oxygen. We established that increased body temperature works both independently and in concert with these two respiratory gases to control human breathing. In the second area we conceived, built and validated a novel breath-by-breath device for precise control the two respiratory gases. In the third area, similar that evident for other human thermoregulatory heat loss responses, we revealed an adaptation of the human thermal panting response after repeated heat stresses. In the proposed research program, we will employ our novel control system for the respiratory gases in 2 areas of study. In the first area, we will determine the mechanism of control of the human gasp response during acute as well as repeated decreases of body temperatures. In the second area, we will ascertain how the human thermal panting response contributes the control of blood pressure, and, in elderly Canadians, we will assess if this human thermal panting adapts to repeated heat stresses. The benefits to all Canadians from this research is to improve our understanding of the human ability to live and proposer in extreme climates, such as those more and more evident in our country with global warming.