目的研究还原型辅酶Ⅱ(NADPH)氧化酶/血管过氧化酶(NOX/VPO)途径在心肌缺血再灌注(L/R)氧化损伤中的作用和机制。方法雄性SD大鼠分为正常对照组,假手术组,缺血再灌注组(L/R组,大鼠心肌缺血1h,再灌注3h),夹竹桃麻素(apocynin)处理组(VR+apocynin组,再灌注开始前30min腹腔注射NOX特异性抑制剂apocynin)和溶媒对照组(L/R+vehicle组,再灌注开始前30min腹腔注射等体积apocynin溶媒)。每组动物数为7~8只。再灌注结束后测定心肌梗死面积、血清肌酸激酶(CK)活性、心肌组织细胞凋亡率和心肌组织细胞凋亡蛋白酶(easpase-3)含量及活性、NOX活性、NOX2和VP01mRNA和蛋白表达水平。结果L/R组VP01、NOX2mRNA和蛋白表达水平、NOX2酶活性水平、CK水平、心肌梗死面积、心肌细胞凋亡率均显著高于假手术组[两组上述指标分别为2.01±0.20比1.01±0.10,0.02±0.39比1.12±0.08,1.15±0.14比0.52±0.08,0.82±0.08比0.53±0.07,(14.1±1.2)比(9.1±1.2)仙mol·L-1·min-1·g-1,(2838.5±315.2)比(715.1±121.2)U/L,(52.1±2.1)%比(0.9±0.1)%和(23.5±3.5)%比(1.8±0.5)%,P均〈0.01]。L/R+apocynin组VP01、NOX2mRNA和蛋白表达水平、NOX2酶活性水平、CK水平、心肌梗死面积、心肌细胞凋亡率[分别为1.51±0.20,0.76±0.06,(12.1±1.0)斗m01.L-1·min-1·g-1,(1795.2±206.3)U/L,(21.5±2.2)%和(8.9±2.3)%]均显著低于I/R组(P均〈0.01)。VR+vehicle组上述指标与FR组比较差异均无统计学意义。结论NOX2/VP01途径在I/R氧化损伤中起重要作用,VP01与NOX2可能以H,0,为中介,共同促进了UR造成的氧化损伤。
Objective To explore the role of NADPH oxidase inhibitor apocynin on ischemia/ reperfusion (I/R)-induced myocardial injury. Methods Male SD rat hearts were divided into the normal control group; sham group; I/R group (1 h ischemia followed by 3 h reperfusion) ; I/R + apocynin group (50 mg/kg, administrated at 30 min before reperfusion) and I/R + vehicle group (same volume vehicle administrated at 30 min before reperfusion). At the end of reperfusion, myocardial infarct size, apoptosis, plasma CK activity, myocardial NOX activity, myocardial caspase-3 expression and activity, myocardial mRNA and protein expressions of vascular peroxidase 1 (VPO1) and NOX2 were measured. Results Infarct size, ratio of cardiomyocyte apoptosis, mRNA and protein expression of VOP1 and NOX2, serum CK, myocardial NOX and easpase-3 activities in the I/R group were all significantly increased compared to those in the sham group (P 〈0. 01 ). Above parameters were similar between//R + vehicle group and I/R group (all P 〉 0. 05 ). Infarct size, ratio of cardiomyocyte apoptosis, myocardial mRNA and protein expression of VOP1 and NOX2, serum CK, myocardial NOX and caspase-3 activities were significantly lower in I/R + apocynin group compared to those in I/R group ( all P 〈 0.01 ). Conclusions NOX/VPO pathway plays an important role in mediating I/R-induced myocardial oxidative injury. NOX inhibition could reduce I/R-induced myocardial oxidative iniurv by attenuating myocardial aoootosis in this model.