Dynamic cardiovascular, respiratory, cerebrovascular interactions

动态心血管、呼吸、脑血管相互作用

• 批准号: 6473-2013
• 负责人: Hughson, Richard
• 金额: $ 3.42万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520926
• 关键词: Dynamic; cardiovascular; respiratory; cerebrovascular; interactions

Our ability to adapt to the challenges of daily life depends on blood flow supply to the working skeletal muscles and to the brain. We plan to explore two topics that highlight the important role of oxygen delivery to working muscles and develop methods that explicitly measure brain blood flow. Our first experiments will explore the impact of ischemic preconditioning to enhance muscle function. Ischemic preconditioning is accomplished by restricting blood flow for short periods of time before a larger challenge to blood flow. Recently we showed that stopping blood flow to a muscle then allowing a brief recovery prior to exercise delayed adaptation of muscle metabolism. We anticipate that ischemic preconditioning will prepare the muscle for the challenge of longer arrest of blood flow allowing the muscle to cope well with exercise. We will add magnetic resonance spectroscopy to our existing techniques to monitor intramuscular metabolic events. Manipulation of oxygen supply to the muscle by changing inspired gas concentrations will allow us to test hypotheses showing the importance of oxygen in regulation of muscle metabolism at the onset of physical activity. Our second series of experiments will examine blood flow to the brain under several conditions. We will compare estimates from brain blood flow velocity through the middle cerebral artery to absolute blood flow in the internal carotid artery in the neck. In preliminary research, we determined that the estimates from the middle cerebral artery velocity are incorrect in many circumstances. We will investigate the effects of different drugs that affect brain blood vessels, changes in blood levels of carbon dioxide and changes in posture to show that velocity does not accurately reflect brain blood flow. We will explore how new models of the properties of brain blood vessels can give us insight into the mechanisms that underlie the precise regulation of brain blood flow. Through this research, students will gain critical knowledge about the integrative cardiovascular and brain blood flow mechanisms that contribute to human physiological responses to physical activity and upright posture in our everyday lives.

我们适应日常生活挑战的能力取决于工作骨骼肌和大脑的血流供应。我们计划探索两个主题，突出氧气输送到工作肌肉的重要作用，并开发明确测量脑血流量的方法。我们的第一个实验将探讨缺血预处理对增强肌肉功能的影响。缺血预处理是通过在对血流的较大挑战之前短时间限制血流来实现的。最近，我们发现，停止血液流向肌肉，然后在运动前进行短暂的恢复，会延迟肌肉代谢的适应。我们预期缺血预处理将使肌肉为更长时间的血流停滞的挑战做好准备，从而使肌肉能够很好地科普运动。我们将在现有技术中增加磁共振波谱学来监测肌内代谢事件。通过改变吸入气体浓度来操纵肌肉的氧气供应，将使我们能够测试表明氧气在体力活动开始时调节肌肉代谢中的重要性的假设。我们的第二系列实验将在几种条件下检查流向大脑的血液。我们将比较通过大脑中动脉的脑血流速度与颈部颈内动脉的绝对血流的估计值。在初步研究中，我们确定大脑中动脉速度的估计在许多情况下是不正确的。我们将研究影响脑血管的不同药物的作用，血液中二氧化碳水平的变化和姿势的变化，以表明速度并不能准确反映脑血流量。我们将探索脑血管特性的新模型如何让我们深入了解脑血流精确调节的机制。通过这项研究，学生将获得有关综合心血管和脑血流机制的关键知识，这些机制有助于人类对日常生活中的身体活动和直立姿势的生理反应。