Movahed A, Nair K G, Ashavaid T F, Kumar P
PD Hinduja National Hospital & Medical Research Centre, Bombay.
Indian Heart J. 1995 Mar-Apr;47(2):107-11.
Prolonged global ischemia followed by reperfusion during coronary artery bypass graft (CABG) surgery leads to a burst of oxygen free-radical generation and subsequent myocardial impairment. Blood samples were collected at different time periods from the right atrium of patients (n = 55) who underwent CABG surgery. Free-radical activity was measured by assays for thiobarbituric acid reactive species (TBARS), mainly malondialdehyde (MDA), at zero minute (before aortic cross-clamp), one minute and 10 minutes after declamping i.e. reperfusion. There was a significant increase (p < 0.001) in the level of MDA at one minute of reperfusion which continued to be elevated up to 10 minutes. This increase was significantly correlated with aortic cross-clamp time (r = 0.525, p < 0.05). The activity of CPK and CPK-MB was raised by two fold (p < 0.001) after release of the clamp. Plasma Troponin-T level was estimated in 10 patients during CABG surgery and a significant increase (p < 0.01) was observed at one minute as well as 10 minutes of reperfusion which correlated well (r = 0.81, p < 0.01) with the severity of ischemia. The concomitant rise in TBARS (marker of free-radical activity), CPK, CPK-MB and Troponin-T (indicators of myocardial damage) on reperfusion implies that there is free-radical mediated damage to the cardiac membrane during CABG surgery.
冠状动脉搭桥术（CABG）期间长时间的全身性缺血后再灌注会导致氧自由基大量生成，继而造成心肌损伤。从接受CABG手术的患者（n = 55）右心房在不同时间段采集血样。通过检测硫代巴比妥酸反应性物质（TBARS），主要是丙二醛（MDA），来测定自由基活性，分别在零分钟（主动脉阻断前）、松开阻断即再灌注后1分钟和10分钟进行检测。再灌注1分钟时MDA水平显著升高（p < 0.001），并持续升高至10分钟。这种升高与主动脉阻断时间显著相关（r = 0.525，p < 0.05）。松开阻断后，肌酸磷酸激酶（CPK）和肌酸磷酸激酶同工酶（CPK-MB）的活性升高了两倍（p < 0.001）。在10例CABG手术患者中测定了血浆肌钙蛋白T水平，再灌注1分钟和10分钟时均观察到显著升高（p < 0.01），且与缺血严重程度相关性良好（r = 0.81，p < 0.01）。再灌注时TBARS（自由基活性标志物）、CPK、CPK-MB和肌钙蛋白T（心肌损伤指标）同时升高，这意味着CABG手术期间存在自由基介导的心肌细胞膜损伤。
