Inafuku Hitoshi, Kuniyoshi Yukio, Yamashiro Satoshi, Arakaki Katsuya, Nagano Takaaki, Morishima Yuji, Kise Yuya
Department of Thoracic and Cardiovascular Surgery, University of the Ryukyus, Nishihara, Okinawa, Japan.
Ann Thorac Cardiovasc Surg. 2013;19(3):186-94. doi: 10.5761/atcs.oa.12.01896. Epub 2012 Aug 31.
Oxidative stress due to reactive oxygen species (ROS) is thought to play a considerable role in ischemia/reperfusion (I/R) injury that impairs cardiac function. The present study examined oxidative damage in I/R injury and investigated the correlation between oxidative stress and impaired cardiac function after I/R injury of the isolated rat heart.
Hearts isolated from male Sprague-Dawley rats were mounted on a Langendorff apparatus. Hearts arrested using St. Thomas cardioplegic solution and then they were reperfused. The hearts were divided into three groups depending on the frequency (0-2) of I/R. After I/R, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), positive maximum left ventricular developing pressure (max LV dP/dt) and coronary flow (CF) were measured. Creatine kinase (CK) was measured in the coronary effluent and 8-hydroxy-2'deoxyguanosine (8OHdG), a marker of oxidative DNA damage, was measured. Adenosine triphosphate (ATP) was measured from frozen myocardial tissue after experiment.
We immunohistochemically demonstrated and quantified levels of 8-OHdG after I/R injury of the heart. The frequency of I/R injury and cardiac dysfunction significantly and negatively correlated. The ATP products were similar among the three groups. The incidence of ventricular arrhythmias was not by affected oxidative stress.
The frequency of I/R injury had more of an effect on 8-OHdG products and on impaired cardiac function with less myocyte damage than ischemic duration within 30 minutes of ischemia.
活性氧（ROS）引起的氧化应激被认为在损害心脏功能的缺血/再灌注（I/R）损伤中起重要作用。本研究检测了I/R损伤中的氧化损伤，并研究了离体大鼠心脏I/R损伤后氧化应激与心脏功能受损之间的相关性。
将雄性Sprague-Dawley大鼠的心脏安装在Langendorff装置上。用圣托马斯心脏停搏液使心脏停搏，然后进行再灌注。根据I/R的频率（0-2次）将心脏分为三组。I/R后，测量左心室舒张末压（LVDP）、左心室舒张末压（LVEDP）、左心室最大正压上升速率（max LV dP/dt）和冠状动脉血流量（CF）。测量冠状动脉流出液中的肌酸激酶（CK），并测量氧化DNA损伤的标志物8-羟基-2'-脱氧鸟苷（8OHdG）。实验结束后，从冷冻的心肌组织中测量三磷酸腺苷（ATP）。
我们通过免疫组织化学方法证实并量化了心脏I/R损伤后8-OHdG的水平。I/R损伤的频率与心脏功能障碍显著负相关。三组之间的ATP产物相似。室性心律失常的发生率不受氧化应激的影响。
在缺血30分钟内，I/R损伤的频率对8-OHdG产物和心脏功能受损的影响更大，而对心肌细胞的损伤较小，相比之下缺血持续时间的影响较小。
