AGING, LIPID PEROXIDATION, AND CARDIAC REPERFUSION

描述(改编自申请人的摘要)：再灌注 心脏组织导致线粒体呼吸下降， 它的严重性随着年龄的增长而增加。对能源状况至关重要， 心脏功能，心肌线粒体表现为再灌流诱导 增加自由基的产生。免费之间的直接联系 自由基和线粒体功能障碍尚未得到证实。4- 羟基-2-壬烯醛(HNE)，易发生脂质过氧化的主要产物 与酶反应并使其失活。来自校长的作品 研究人员的实验室已经证实，再灌注导致 HNE对特定蛋白质的修饰。HNE修饰的水平 线粒体呼吸随年龄增长而下降。 HNE浓度对完整心肌线粒体的治疗作用 再灌流期间的预期导致NADH依赖的快速下降 呼吸与再灌流时的呼吸相似。《校长》 研究人员因此提出：再灌流导致的心脏功能下降 线粒体呼吸作用在一定程度上是由于特定的 线粒体蛋白(S)由HNE表达，这些过程有助于 与年龄相关的心肌再灌注损伤增加。 为了验证这一假设，从不同年龄的大鼠分离出的心脏 会受到不同时间的缺血和再灌流。 然后将分离线粒体以确定： 1.特定呼吸酶在缺血和缺氧时失活 再灌流。 2.经HNE修饰的线粒体蛋白(S)的同源性 HNE修饰的级别。 3.线粒体对HNE损伤和超氧化物歧化敏感性的变化 负离子产生。 化学、免疫化学和质谱学技术将被 用于检测和纯化HNE修饰的蛋白质。两性关系 HNE修饰的线粒体蛋白水平与同源性之间的关系 (AIM 2)和表现出再灌流诱导的活动下降的那些 (目标1)将定义线粒体丢失的机制 在再灌流期间的功能。HNE介导的损伤的决定因素 线粒体将通过评估线粒体的变化来建立 在老化和缺血期间发生的特性(目标1)，并导致 HNE形成率升高和/或易感性增加 特定的呼吸酶进行修饰(目标3)。身份识别 心肌再灌注损伤的具体机制和条件 如果要实现干预，就必须在什么情况下发生这些问题。

DESCRIPTION (Adapted from the Applicant's Abstract): Reperfusion of cardiac tissue results in declines in mitochondrial respiration, the severity of which increases with age. Critical to the energy status and function of the heart, cardiac mitochondria exhibit reperfusion-induced increases in free radical production. A direct link between free radicals and mitochondrial dysfunction has yet to be established. 4- Hydroxy-2-nonenal (HNE), a major product of lipid peroxidation readily reacts with and inactivates enzymes. Work from the Principal Investigator's laboratory had established that reperfusion results in modification of specific proteins by HNE. The level of HNE modification increases with age and parallels declines in mitochondrial respiration. Treatment of intact cardiac mitochondria with concentrations of HNE expected during reperfusion causes rapid declines in NADH-dependent respiration similar to that observed during reperfusion. The Principal Investigator thus proposes that: Reperfusion-induced declines in mitochondrial respiration are due, in part, to modification of specific mitochondrial proteins(s) by HNE and that these processes contribute to age-related increases in myocardial reperfusion injury. To test this hypothesis, hearts isolated from rats of different ages will be subjected to varying durations of ischemia and reperfusion. Mitochondria will then be isolated to determine: 1. Specific respiratory enzymes inactivated during ischemia and reperfusion. 2. The identities of mitochondrial protein(s) modified by HNE and the level of HNE modification. 3. Changes in mitochondrial susceptibility to HNE damage and superoxide anion generation. Chemical, immunochemical, and mass spectroscopic techniques will be utilized to detect and purify HNE-modified protein. Relationships between the level and identity of mitochondrial proteins modified by HNE (Aim 2) and those exhibiting reperfusion-induced declines in activity (Aim 1) will define mechanisms responsible for loss in mitochondrial function during reperfusion. Determinants of HNE-mediated damage to mitochondria will be established by evaluating changes in mitochondrial properties which occur during aging and ischemia (Aim 1) and result in elevated rates of HNE formation and/or increased susceptibility of specific respiratory enzymes to modification (Aim 3). Identification of specific mechanisms of myocardial reperfusion injury and conditions under which they occur is necessary if intervention is to be achieved.