PEROXYLIPIDS/NITRIC OXIDE IN THROMBOTIC STROKE

血栓性中风中的过氧脂质/一氧化氮

• 批准号: 2379621
• 负责人: BRANT D WATSON
• 金额: $ 24.81万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-08-01 至 1999-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2379621
• 关键词: cerebral ischemia /hypoxia; diene; growth factor; histopathology; infarct; laboratory rat; light microscopy; lipid peroxides; membrane channels; myocardial infarct sizing; nitric oxide; perfusion; reperfusion; stroke; thrombosis; tissue /cell culture

The broad objective of this proposal is to demonstrate that the collateral vascular response to experimental thrombotic stroke of the middle cerebral artery (MCA) territory in the rat can be controlled by stimulating or inhibiting the synthesis of endothelial-derived relaxing factor (EDRF). If this assertion is correct, the volume of MCA territory infarct should be maximal and consistent if EDRF synthesis is suppressed (specific aim 1), and minimized (but likely inconsistent) if EDRF synthesis is enhanced (specific aim 2). Observation of infarct consistency in a normally well- collateralized but not carotid artery-ligated (Wistar) rat would be unprecedented, and important for evaluation of anti-ischemic drugs. Observation of infarct mitigation by EDRF stimulation would suggest that EDRF-induced activation of collateral circulation be used clinically to reduce infarct volume, even if the MCA (or other intracranial artery) remains occluded. In specific aim 3, infarct volume and consistency will be monitored in rats initially subjected to EDRF inhibition and MCA thrombosis (for time periods of up to 3 hours) after complete restoration of anterograde flow by lysis of the MCA thrombi together with EDRF enhancement. Under these apparently optimal reflow conditions, however, the theoretical possibility of reperfusion injury should also be maximized. This paradox will be evaluated histopathologically and biochemically (in terms of peroxidized lipid conjugated dienes) for this aim, and for the first two also (specific aim 4), thus facilitating assessment of the long- hypothesized contribution of (presumably) oxygen radical-mediated lipid peroxidation to the initiation of reperfusion injury. In our methodology the MCA thrombi are formed in specific arterial segments in response to photochemically induced endothelial injury mediated by an intravenously injected dye in conjunction with a focussed laser beam of the appropriate wavelength. Thrombi formed in response to rose bengal injection and irradiation with an argon/dye laser beam at 562 nm can be lysed by hementin (from the leech Haementeria ghilianii). Inhibition of EDRF synthesis is achieved by intravenous infusion of NG-nitro-1-arginine methyl ester hydrochloride (1-NAME), while enhancement of EDRF synthesis is achieved with infusion of either 1-arginine hydrochloride (ARG) or N(alpha)-benzoyl-l-arginine ethyl ester hydrochloride (BAEE). Conjugated diene content is analyzed spectroscopically in total lipid extracts from small (less than 1 mg) cortical punch biopsies. Under the conditions of aim 3 the detection of lipid peroxidation in time during reperfusion should be much more consistent compared to previous efforts.

该提议的广泛目标是证明抵押品 对中大脑的实验性血栓性中风的血管反应 大鼠中的动脉（MCA）可以通过刺激或 抑制内皮衍生的放松因子（EDRF）的合成。 如果 这个断言是正确的，MCA领土梗塞的体积应为 如果抑制EDRF合成，则最大和一致（特定目标1）， 如果EDRF合成增强，并且最小化（但可能不一致） （特定目标2）。 观察正常良好的梗死一致性 抵押但未颈动脉绑扎（Wistar）大鼠的大鼠是 前所未有的，对于评估抗缺血药物很重要。 通过EDRF刺激观察梗塞减轻梗塞会表明 EDRF诱导的附带循环的激活可用于临床 即使MCA（或其他颅内动脉）也会减少梗塞体积 仍然被阻塞。 在特定的目标3中，梗塞量和一致性将 在最初受到EDRF抑制和MCA的大鼠中受到监测 完全修复后血栓形成（最多3小时的时间段） 通过MCA血栓裂解与EDRF一起裂解的顺行流程 增强。 但是，在这些显然是最佳的回流条件下 再灌注损伤的理论可能性也应最大化。 该悖论将通过组织病理学和生化评估（在 对于此目标的过氧化脂质结合二烯的条款，以及 前两个也（特定目标4），从而促进了对长期的评估 （可能是）氧自由基介导的脂质的假设贡献 对再灌注损伤的启动过氧化。 在我们的方法论中，MCA血栓形成在特定的动脉段 响应于光化学诱导的内皮损伤 静脉注射染料与焦点的激光束结合 适当的波长。 响应玫瑰孟加拉的血栓形成 在562 nm处用氩/染料激光束注射和辐射可以是 由hementin（来自ghilianii的水hementeria）裂解。 抑制 EDRF合成是通过静脉输注NG-硝基-1-精氨酸来实现的 盐酸甲基酯（1-名），而EDRF合成的增强是 通过输注1-精氨酸盐酸盐（ARG）或 N（Alpha）-Benzoyl-L-精氨酸乙酯盐酸酯（BAEE）。 共轭 二烯含量在总脂质提取物中分析 小（小于1 mg）皮质拳活检。 在条件下 目标3在再灌注过程中的时间及时检测脂质过氧化应 与以前的努力相比，要保持一致得多。