还原型辅酶Ⅱ氧化酶／血管过氧化酶途径促大鼠心肌缺血再灌注氧化损伤

NADPH oxidase inhibitor apocynin attenuates ischemia/reperfusion induced myocardial injury inrats

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.