MOLECULAR MECHANISMS--ISCHEMIA/REPERFUSION BRAIN INJURY

描述：(改编自研究人员摘要)自由基- 介导对脂质和蛋白质的损伤，改变线粒体电子 运输链活性与组织代谢异常模式 与神经系统疾病的病理生理学密切相关 由全脑缺血和再灌流引起。整体而言 本项目的目标是描述 这些因素以及它们与观察到的神经损伤之间的关系 动物受到临床相关场景的影响，包括 心脏骤停后30分钟至24小时恢复 自发循环。 这些研究的具体目的是检验以下假设： (1)短时间的全脑缺血可引起即刻和可逆 线粒体呼吸和钙摄取活性的改变 与延迟的、再灌注引起的改变是不同的。(2) 脑缺血/再灌流所致的自由基损伤 影响线粒体和其他组织中存在的蛋白质和脂类 细胞室和细胞膜。(3)线粒体膜损伤 和酶失活导致立即和延迟的变化 心脏骤停和ROSC后的脑能量代谢。(4) 灵感和脑02的临床可行手法 浓度改变了分子、亚细胞和代谢的程度 损伤，对应于神经损伤程度的不同 按照这些不同的复苏方案观察。 实现这些目标的方法将包括测量02 离体脑的消耗、过氧化氢形成和钙摄取 线粒体和洋地黄素通透性突触神经体与PC12 嗜铬细胞瘤细胞.脂肪和蛋白质氧化的测定 磷脂和游离脂肪酸部分的测定和 与糖酵解有关的代谢活动的测定 三氯乙烷循环。对参与特定项目的其他支持 亚细胞和代谢改变在急性髓细胞白血病发病中的作用 脑缺血/再灌注性损伤将来自于结果的比较 通过不同的动物治疗方案以及通过 神经化学测量和组织学检测。体外建模 细胞和亚细胞损伤的研究也将有助于阐明 因果关系。这些研究的意义 它们将提供独特的分子洞察力，了解 改变的生物能量学和自由基代谢在脑损伤中的作用 与心脏骤停和复苏以及其他形式有关 包括中风和创伤在内的脑缺血。

DESCRIPTION: (Adapted from investigator's abstract) Free radical- mediated damage to lipids and proteins, altered mitochondrial electron transport chain activities and abnormal patterns of tissue metabolism are strongly implicated in the pathophysiology of neurological morbidity caused by global cerebral ischemia and reperfusion. The overall objective of this project is to characterize the relationships between these factors and to relate them to the neurological impairment observed with animals subjected to a clinically relevant scenario consisting of cardiac arrest followed by 30 minutes to 24 hours of restoration of spontaneous circulation. The specific aims of these studies are to test the following hypotheses: (1) A short period of global ischemia causes immediate and reversible alterations in mitochondrial respiratory and Ca2+ uptake activities that are distinguishable from delayed, reperfusion-induced alterations. (2) Free radical damage due to cerebral ischemia/reperfusion adversely affects proteins as well as lipids present within mitochondria and other cellular compartments and membranes. (3) Mitochondrial membrane damage and enzyme inactivation result in immediate and delayed alterations in cerebral energy metabolism following cardiac arrest and ROSC. (4) Clinically-feasible manipulations of inspired and brain 02 concentrations alter the degree of molecular, subcellular, and metabolic injury, corresponding to differences in the extent of neurological injury observed following these different resuscitation protocols. Methods of approach to these aims will include measurements of 02 consumption, peroxide formation and Ca2+ uptake by isolated brain mitochondria and digitonin-permeabilized synaptoneurosomes and PC12 pheochromocytoma cells; determinations of lipid and protein oxidation, measurements of phospholipid and free fatty acid moieties and determinations of metabolic activities associated with glycolysis and the TCA cycle. Additional support for involvement of specific subcellular and metabolic alterations in the pathogenesis of ischemia/reperfusion brain injury will come from comparison of results obtained with different animal treatment protocols as well as with neurochemical measurements and histological testes. In vitro modeling of cellular and subcellular injury will also assist in the elucidation of cause and effect relationships. The significance of these studies is that they will provide unique molecular insight into the roles that altered bioenergetics and free-radical-metabolism play in brain injury associated with cardiac arrest and resuscitation as well as other forms of cerebral ischemia including stroke and trauma.