Adenosine and oxidative stress in myocardial tissue

心肌组织中的腺苷和氧化应激

• 批准号: 6538026
• 负责人: RANDY M STEVENS
• 金额: $ 4.82万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6538026
• 关键词: adenosine; antioxidants; cardiac myocytes; cytoprotection; fluorescent dye /probe; glutathione; heart contraction; laboratory rat; microdialysis; myocardial ischemia /hypoxia; oxidative stress; postdoctoral investigator; purinergic receptor; swine; tissue /cell culture

The goal of this project is to develop new therapeutic strategies to improve myocardial tolerance to ischemia by targeting the heart's endogenous defense mechanisms against oxidative stress. The specific aim of the proposed research is to determine the mechanism(s) whereby adenosine and adenosine receptor activation reduce cellular and subcellular reactive oxygen species (RO2) formation and oxidative stress; and the role adenosine plays in enhancing endogenous antioxidant defense mechanisms. Studies will be performed in isolated rat ventricular myocytes and a porcine in vivo regional ischemia preparation. In the in vivo porcine studies, the cardiac microdialysis technique will be used to measure interstitial fluid levels of ROS. Contractile dysfunction will be evaluated by load insensitive measures of regional contractility. In myocytes, RO2 will be measures with the fluorescent probe dichlorofluorescein diacetate, contractility. In myocytes, ROS will be measured with the fluorescent probe dichlorofluorescein diacetate, and mitochondrial oxidative stress will be estimated by monitoring mitochondrial flavoprotein autofluorescence. Oxidative stress and cell function will be measured in myocytes submitted to stimulated ischemia and reperfusion. Antioxidant levels will be determined by measuring reduced glutathione, oxidized glutathione and the NADPH/NADP+ ratio. The effects of adenosine receptor agonists, alone and in combination of oxidative stress and antioxidant status will be correlated with myocyte twitch amplitude and the extent of stunning and cell function following hypoxia-reoxygenation. The findings could lead to the development of new therapeutic strategies to improve hemodynamic performance and survival in patients with ischemic heart disease.

该项目的目标是开发新的治疗策略，通过靶向心脏对氧化应激的内源性防御机制来提高心肌对缺血的耐受性。拟议研究的具体目的是确定腺苷和腺苷受体激活减少细胞和亚细胞活性氧（RO 2）形成和氧化应激的机制;以及腺苷在增强内源性抗氧化防御机制中的作用。将在分离的大鼠心室肌细胞和猪体内局部缺血制备物中进行研究。在体内猪研究中，心脏微透析技术将用于测量ROS的间质液水平。收缩功能障碍将通过局部收缩力的负荷不敏感测量来评价。在肌细胞中，RO 2将用荧光探针二氯荧光素二乙酸酯测量收缩性。在肌细胞中，将用荧光探针二氯荧光素二乙酸酯测量ROS，并通过监测线粒体黄素蛋白自发荧光来估计线粒体氧化应激。将在经受刺激的缺血和再灌注的肌细胞中测量氧化应激和细胞功能。将通过测量还原型谷胱甘肽、氧化型谷胱甘肽和NADPH/NADP+比值来确定抗氧化剂水平。腺苷受体激动剂单独和与氧化应激和抗氧化状态组合的作用将与缺氧-复氧后的肌细胞抽搐幅度和顿抑程度以及细胞功能相关。这一发现可能会导致新的治疗策略的发展，以改善缺血性心脏病患者的血流动力学性能和生存率。