The Clarification of Mechanisms for Electron Transfer and Identification of Radicals in Myocardium

心肌中电子传递机制的阐明和自由基的识别

• 批准号: 62570404
• 负责人: NAKAZAWA Hiroe
• 金额: $ 1.15万
• 依托单位: Tokai University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62570404/
• 关键词: Myocardium; Coenzyme Q_<10> Radical; 虚血; Coenzyme Q_<10>アニオンラジカル; Coenzyne Q_<10>アニオンラジカル

This study indirectly showed the involvement of oxygen derived free radicals (O_2-FR) in reperfusion injury by the myocardial protection of radical scavengers and directly demonstrated free radicals in the frozem myocardium using electron spin resonance (ESR) spectroscopy.In 19 open chest dogs, the left anterior descending coronary artery was occluded for 90 min and subsequently reperfused for 60 min. The severity of myocardial injury was evaluated by ratios of necrotic to perfused areas determined by dual fluorescence methods. Dogs treated with SOD, catalase and mannitol disclosed significantly limited necrosis than that in control (34.1 12.0 vs. 66.0 11.3%); indirectly veraifying that the O_2-FR play an important role in the genesis of ischemia/reperfusion injury.For direct proof of free radical hypothesis, radicals in the frozen myocardium were measured using electron spin resonance spectroscopy (ESR). The ESR spectra exhibited four radicals, however, two radicals which had been previously claimed as O_2-FR and N-centered radical by other investigators were shown as mechanically yielded artifactual radicals. In artifact-free samples, O_2-FR could not be detected. One radical native to the myocardium was identified as coenzyme Q_<10> radical which might provide an index of severity of reperfusion injury. Spin trapping method with ESR can be an optimal method for the direct measurement of oxygen derived radicals.

本研究通过自由基清除剂对心肌的保护作用间接显示了氧自由基（O_2-FR）参与再灌注损伤，并利用电子自旋共振（ESR）技术直接显示了冰冻心肌中的自由基。结扎左冠状动脉前降支90 min，再灌注60 min，用通过双荧光法测定坏死与灌注面积的比率。用SOD、过氧化氢酶和甘露醇处理的犬心肌坏死率明显低于对照组（34.1 ± 12.0 vs.66.0 ± 11.3%），间接证实了O_2-FR在缺血/再灌注损伤的发生中起重要作用。ESR谱显示出四个自由基，然而，其他研究者先前认为是O_2-FR和N中心自由基的两个自由基被证明是机械产生的人为自由基。在无伪影的样品中，O_2-FR不能被检测到。辅酶Q自由<10>基可作为反映再灌注损伤程度的指标。自旋捕集ESR法是直接测量氧自由基的最佳方法。

项目成果

Hiroe Nakazawa,et al.: Circulation. 74. II-433 (1986)

Hiroe Nakazawa 等人：循环。

Kohji Ichimori,et al.: Circulation. 74. II-199 (1987)

Kohji Ichimori 等人：循环。

Hiroe Nakazawa,et al.: Am J Physiology. 255. H213-H215 (1988)

Hiroe Nakazawa 等人：Am J Physiology。

中沢博江 他: "フリーラジカルの臨床Vol 3" 日本医学館, 134 (1988)

Hiroe Nakazawa 等：“自由基的临床研究第 3 卷”日本医学博物馆，134（1988）

Kohji Ichimori et al.: Circulation. 76. 2-199 (1987)

Kohji Ichimori 等人：循环。