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.

本提案的主要目标是证明担保品 实验性大脑中动脉血栓性卒中的血管反应 大鼠的大脑中动脉（MCA）区域可以通过刺激或 抑制内皮源性舒张因子（EDRF）的合成。 如果 这种说法是正确的，MCA区域梗死的体积应该是 如果EDRF合成被抑制，则最大且一致（具体目标1）， 如果增强EDRF合成， （具体目标2）。 在正常情况下观察梗死一致性- 侧支化但未颈动脉结扎的（Wistar）大鼠 这是前所未有的，对于评价抗缺血药物具有重要意义。 通过EDRF刺激观察到的梗死缓解表明， EDRF诱导的侧支循环激活可用于临床， 减少梗死体积，即使MCA（或其他颅内动脉） 仍然闭塞。 在具体目标3中，梗塞体积和稠度将 在最初进行EDRF抑制和MCA的大鼠中进行监测 完全恢复后血栓形成（持续时间长达3小时） 通过溶解MCA血栓和EDRF实现顺行血流 增强 然而，在这些明显最佳的回流条件下， 再灌注损伤的理论可能性也应最大化。 这种矛盾将在组织病理学和生物化学（ 术语为过氧化脂质共轭二烯）， 前两项也是（具体目标4），从而便利评估长期的 氧自由基介导脂质的假设贡献 过氧化反应对再灌注损伤的起始。 在我们的方法中，MCA血栓形成于特定的动脉段 在对光化学诱导的内皮损伤的反应中， 静脉内注射的染料与聚焦的激光束结合， 合适的波长。 虎红引起血栓形成 注入和用562 nm氩/染料激光束照射可以 被血红素蛋白（来自水蛭Haementeria ghilianii）溶解。 抑制 EDRF合成通过静脉输注NG-硝基-1-精氨酸实现 甲基酯盐酸盐（1-NAME），而增强EDRF合成是 通过输注1-精氨酸盐酸盐（ARG）或 N（α）-苯甲酰基-L-精氨酸乙酯盐酸盐（BAEE）。 缀合 用光谱法分析了来自以下的总脂质提取物中的二烯含量： 小（小于1 mg）皮质穿刺活检。 条件下 目的3再灌注过程中及时检测脂质过氧化反应， 与以前的努力相比更加一致。