Sympathetic Vascular Regulation following Heat Stress in Young and Aged Humans

项目总结/摘要 心血管疾病（CVD）是发达国家的主要死亡原因。年龄是 心血管疾病的主要危险因素和人类的平均寿命正在增加，预计心血管疾病将 达到前所未有的水平，给医疗系统带来巨大负担。虽然这些 人口结构的变化是不可避免的，CVD的发展是可以预防的。如高血压 占更多的心血管疾病死亡比任何其他可改变的风险因素，干预措施，旨在 血压管理是至关重要的，在防止这些清醒的CVD预测， 变成现实热疗法，以热水浴和桑拿浴的形式，是一种古老的做法， 最近在治疗和预防心血管疾病方面获得了关注，因为经常使用桑拿浴与 降低了全因心血管疾病死亡的风险。像运动一样，热量的许多慢性益处 治疗可能是在恢复期间介导的。例如，一次运动 促进血压持续降低，称为运动后低血压， 短暂降低升高的血压至正常血压范围， 心血管适应与运动训练。同样，我们和其他人已经证明了 持续降低血压后，单回合的热应激，在健康和 患者人群。然而，这种后加热的神经血管机制 潜在的机会窗口是未知的，这代表着知识上的重大差距。因此，我们认为， 我们的目的是探讨加热后低血压，压力反射控制，交感血管， 在年轻人和老年人全身热应激后的转导。我们假设 加热后的低血压是由向下和向下的压力感受性反射复位支持的， 交感神经血管传导的改变。另外我们 假设这种血压降低和压力反射重置的幅度是 在老年人中被夸大了。总的来说，这项工作提高了我们对适应性作用的理解 热应激和先进的热疗法作为一种治疗选择的管理血液 压力和预防CVD。作为候选人，拉森女士完成了拟议的研究， 在俄勒冈州大学与她经验丰富的共同导师Minson博士和Halliwill博士一起，她将 获得临床试验研究经验，学习“金标准”技术实验室技能，并继续 发展成为一个有效的科学传播者，教育者和导师。因此，拟议的 该项目将作为实现拉森更大职业目标的一个重要部分， 博士研究职位，并最终在一所主要的研究型大学任教。

PROJECT SUMMARY/ABSTRACT Cardiovascular disease (CVD) is the leading cause of death in the developed world. As age is a major risk factor for CVD and the average lifespan of humans is increasing, CVD is projected to reach unprecedented levels and place an enormous burden on the healthcare system. While these demographic shifts are inevitable, the development of CVD is preventable. As high blood pressure accounts for more CVD deaths than any other modifiable risk factor, interventions aimed at the management of blood pressure are crucial in preventing these sobering CVD projections from becoming reality. Heat therapy, in the form of hot bath and sauna, is an ancient practice that has recently gained attention in the treatment and prevention of CVD as regular sauna use is associated with a reduced risk of all-cause CVD deaths. Like exercise, many of the chronic benefits of heat therapy are likely mediated during the recovery period. For example, a single bout of exercise promotes a sustained reduction in blood pressure, termed post-exercise hypotension, which transiently lowers elevated blood pressure into normotensive ranges and potentiates beneficial cardiovascular adaptation with exercise training. Similarly, we and others have demonstrated a sustained reduction in blood pressure following a single bout of heat stress in both healthy and patient populations. However, the neurovascular mechanisms which underlie this post-heating hypotensive window of opportunity are unknown, representing a critical gap in knowledge. Therefore, we aim to explore post-heating hypotension, baroreflex control, and sympathetic vascular transduction in young and aged humans following whole-body heat stress. We hypothesize that post-heating hypotension is supported by downward and leftward baroreflex resetting in the absence of altered sympathetic vascular transduction in both young and aged adults. Additionally, we hypothesize that the magnitude of this blood pressure reduction and baroreflex resetting is exaggerated among aged adults. Overall, this work improves our understanding of the adaptive role of heat stress and advances heat therapy as a therapeutic option for the management of blood pressure and prevention of CVD. As the candidate, Ms. Larson completes the proposed research at the University of Oregon alongside her experienced co-mentors, Drs. Minson and Halliwill, she will gain clinical trial research experience, learn “gold-standard” technical laboratory skills, and continue to develop as an effective science communicator, educator, and mentor. As such, the proposed project will serve as an essential installment toward Ms. Larson’s larger career goal to obtain a post- doctoral research position and eventual faculty position at a major research university.