Pretreatment with hyperoxia reduces in vivo infarct size and cell death by apoptosis with an early and delayed phase of protection
Pretreatment with hyperoxia reduces in vivo infarct size and cell death by apoptosis with an early and delayed phase of protection
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DOI：
10.1016/j.ejcts.2010.05.036
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发表时间：
2011-02-01
影响因子：
3.4
通讯作者：
Khoshbaten, Ali
中科院分区：
文献类型：
--
作者：
Foadoddini, Mohsen;Esmailidehaj, Mansour;Khoshbaten, Ali
目的：常压高氧暴露可保护心脏免受离体缺血再灌注损伤。在本研究中，我们研究了早期和晚期高氧对体内心肌梗死和细胞凋亡的影响。方法：将大鼠暴露于室内空气预氧合（O(2) >= 95%），然后进行局部缺血（30 分钟）和 0、90、180 和 360 分钟的再灌注。在冠状动脉闭塞前立即或24小时进行高氧暴露120分钟，然后再灌注360分钟。通过伊文思蓝/氯化三苯基四唑染色评估梗塞大小。通过末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸（dUTP）缺口末端标记（TUNEL）评估梗塞区域的细胞凋亡。通过荧光酶测定法测量 Caspase 3 活性，通过蛋白质印迹法评估 Bcl-2 和 Bax 蛋白表达，并通过 DNA 凝胶电泳评估 DNA 梯状图。结果：梗死面积并不随着再灌注持续时间的增加而增加。然而，通过 Bcl-2/Bax 比率、caspase 3 活性和 TUNEL 阳性细胞评估的细胞凋亡随着再灌注时间的增加而增加。早期和延迟高氧预处理均可减少梗塞面积（p = 0.0013，p = 0.046），改善缺血性心律失常并增加 Bcl-2/Bax 比率（p = 0.015，p = 0.0159）。仅在冠状动脉闭塞前即刻的高氧会降低 caspase 3 活性 (p = 0.026) 并降低 TUNEL 阳性染色 (p = 0.046)，且没有可见的 DNA 阶梯。结论：心肌细胞凋亡的检测随着再灌注时间的延长而增加，与梗塞检测相反，在梗塞检测中，再灌注对于检测梗塞至关重要，但梗塞面积不随时间增加。高氧预处理显着减少了梗塞面积和凋亡细胞死亡。在冠状动脉闭塞之前进行预处理对心脏保护作用最强。 (C) 2010 年欧洲心胸外科协会。由 Elsevier B.V. 出版。保留所有权利。
Objective: Exposure to normobaric hyperoxia protects the heart against ischemia reperfusion injury ex vivo. In the present study, we investigated the effect of the early and late phase of hyperoxia on in vivo myocardial infarction and apoptosis. Methods: Rats were exposed to room air preoxygenation (O(2) >= 95%) followed by regional ischemia (30 min) and 0, 90, 180, and 360 min of reperfusion. Hyperoxic exposure was performed for 120 min either immediately or 24 h before coronary occlusion followed by 360-min reperfusion. Infarct size was evaluated by Evans blue/triphenyltetrazolium chloride staining. Apoptosis in the infarcted area was evaluated by terminal deoxy-nucleotidyl transferase-mediated deoxy uridine triphosphate (dUTP) nick end-labeling (TUNEL). Caspase 3 activity was measured by fluorometric enzyme assay, Bcl-2 and Bax protein expression assessed by western blotting and DNA laddering assessed with DNA gel electrophoresis. Results: The infarct size did not increase with increasing duration of reperfusion. However, apoptosis as evaluated by Bcl-2/Bax ratio, caspase 3 activity, and TUNEL-positive cells increased with increasing time of reperfusion. Both early and delayed pretreatment with hyperoxia reduced infarct size (p = 0.0013, p = 0.046), ameliorated ischemic arrhythmias and increased Bcl-2/Bax ratio (p = 0.015, p = 0.0159). Only hyperoxia immediately before coronary occlusion decreased caspase 3 activity (p = 0.026) and decreased TUNEL-positive staining (p = 0.046) with no visible DNA laddering. Conclusions: Detection of myocardial apoptosis increased with prolongation of reperfusion time, as opposed to infarct detection where reperfusion was essential to detect infarction, but the infarct size did not increase with time. Pretreatment with hyperoxia significantly decreased infarct size and apoptotic cell death. Pretreatment, immediately before coronary occlusion, was most cardioprotective. (C) 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.