Exercise Pressor Reflex Dysfunction in Heart Failure: Mechanisms and Treatment

项目总结 目前，美国约有650万男性和女性患有心力衰竭。到2030年， 预计这一数字将攀升至850万以上，与心力衰竭相关的直接医疗费用预计将达到 531亿美元。心力衰竭患者通常表现出交感神经过度紧张。 与健康受试者在休息和运动过程中的系统活动进行比较。夸大了……的增长 运动中的交感神经系统活动(即交感神经兴奋)是运动的直接贡献者 不耐受和缺乏功能独立性是心力衰竭患者寻求医疗服务的主要原因 关心。一种神经反射，由收缩的骨骼肌中的机械和代谢信号激活 对运动过程中交感神经系统活动的增加有重要作用。在……里面 心力衰竭患者，这种被称为运动加压反射的反射的激活被夸大了 运动性交感神经兴奋是其机制基础。目前，还没有一种疗法是 专为减少心力衰竭患者运动加压反射的激活而设计，这反映了 我们目前对造成其夸大的机制的了解有限。我们将使用男性和 心衰雌性大鼠(心肌梗死后模型)的机制研究 夸大运动加压反射的基础和可能的治疗靶点。在目标1中，我们将调查 内源性过氧化脂质(EP)4受体在前列腺素刺激下所起的作用 骨骼肌，在心力衰竭时唤起运动升压反射。在目标2中，我们将调查 在心力衰竭时，由机械激活的Piezo2通道在唤起运动升压反射中发挥作用。在AIM 3，我们将研究外周刺激δ-阿片受体是否会减少心脏的运动加压反射 失败了。我们将使用整体动物和分子水平的互补混合来研究这些目标 方法，使我们的调查结果是综合的和可翻译的。总的来说，我们的实验可能确定了三个 治疗的可能靶点(EP4受体、Piezo2通道和δ-阿片受体)旨在1)缓解 运动中产生的交感神经兴奋和2)增加运动耐量，功能 心力衰竭患者的独立性和总体生活质量。

PROJECT SUMMARY There are currently ~6.5 million men and women in the United States with heart failure. By 2030, that number is predicted to climb to over 8.5 million and direct heart failure-related health care costs are predicted to command $53.1 billion. Heart failure patients commonly exhibit exaggerated levels of sympathetic nervous system activity at rest and during exercise compared to healthy subjects. An exaggerated increase in sympathetic nervous system activity during exercise (i.e., sympatho-excitation) is a direct contributor to exercise intolerance and lack of functional independence which is the main reason that heart failure patients seek medical care. A neural reflex that is activated by mechanical and metabolic signals within contracting skeletal muscles contributes importantly to the increase in sympathetic nervous system activity that occurs during exercise. In heart failure patients, the activation of this reflex, termed the exercise pressor reflex, is exaggerated which underlies mechanistically the exercise-induced sympatho-excitation. Currently, there are no therapies that are designed specifically to reduce the activation of the exercise pressor reflex in heart failure patients which reflects our current limited understanding of the mechanisms that contribute to its exaggeration. We will use male and female rats with surgically-induced heart failure (post-myocardial infarction model) to study the mechanistic bases and possible therapeutic targets of the exaggerated exercise pressor reflex. In Aim 1, we will investigate the role played by endoperoxide (EP) 4 receptors, which are stimulated by prostaglandins produced within skeletal muscles, in evoking the exercise pressor reflex in heart failure. In Aim 2, we will investigate the role played by mechanically activated piezo2 channels in evoking the exercise pressor reflex in heart failure. In Aim 3, we will investigate whether peripheral δ-opioid receptor stimulation reduces the exercise pressor reflex in heart failure. We will investigate these aims using a complementary blend of whole animal and molecular level approaches so that our findings are integrative and translational. Collectively, our experiments may identity three possible targets (EP4 receptors, piezo2 channels, and δ-opioid receptors) for therapies aimed at 1) mitigating the sympatho-excitation that occurs during exercise and 2) increasing exercise tolerance, functional independence, and overall quality of life in heart failure patients.