目的探讨重组人可溶性补体受体1型SCR15-18片段(sCR1-SCR15-18)对心肌缺血再灌注的保护作用。方法36只SD大鼠随机分为假手术(SO)组,缺血再灌注(I/R)组和sCR1-SCR15-18(sCR1)保护组。建立急性心肌缺血再灌注模型,结扎冠状动脉前立即注射磷酸盐缓冲液(0.1mL/100g)或sCR1-SCR15-18蛋白(15mg/kg)。测定心肌梗塞面积,血清中乳酸脱氢酶(LDH)和肌酸激酶(CK),心肌组织髓过氧化物酶(MPO)活性,HE染色观察心肌病理改变和免疫组织化学法检测C3c。结果(1)心肌梗死面积:I/R组为(22.9±3.0)%,sCR1保护组为(16.1±3.3)%(P〈0.05)。(2)血清心肌酶CK(U/L):I/R组为3400.9±534.9,sCR1保护组为2532.5±597.1(P〈0.05)。LDH(U/L):I/R组为6572.0±476.3,sCR1保护组为5436.2±611.3(P〈0.05)。(3)心肌组织MPO活性(U/g):I/R组为1.12±0.13,sCR1保护组为0.81±0.14(P〈0.05)。(4)心肌病理改变:I/R组心肌有断裂、坏死,间质肿胀,出血及中性粒细胞浸润,sCR1保护组心肌的以上病理变化明显较I/R组减轻。(5)与I/R组比sCR1保护组梗死区心肌组织C3c的沉积减少。结论sCR1-SCR15-18蛋白对大鼠急性心肌缺血再灌注损伤具有保护作用。
Objective To investigate the protective effects of recombinant SCR15-18 domain of human soluble complement receptor type 1 (sCR1-SCR-15-18) in rats underwent myocardial ischemia and reperfusion (I/R). Methods Sprague-Dawley rats were randomly divided into three groups ( n = 12 each group): sham (SO); 30 min ischemia/3h reperfusion (I/R) and I/R plus sCR1-SCR15-18 (15 mg/kg before I/R, sCR1 ), Serum LDH, CK and cardiac myeloperoxidase (MPO) activity were measured. Infarct size, myocardial histopathological changes and myocardial C3c were also compared among groups. Results Infarct size [ ( 16. 1 ± 3.3 ) % vs. (22. 9 ± 3.0) %, infarct zone/left ventricular mass, P 〈 0. 05 ] and CK [ (2532.5±597.1) U/L vs. (3400.9±534.9) U/L, P〈 0. 05 ] and LDH [ (5436.2 ±611.3) U/L vs. (6572. 0 ± 476. 3 ) U/L, P 〈 0. 05 ] as well as MPO activity in infarct zone [ (0. 81 ± 0. 14) U/g vs. ( 1. 12 ± 0. 13 ) U/g, P 〈 0. 05 ] were significantly decreased post sCR1 compared to I/R group, sCR1 also significantly attenuated histological myocardial injury and reduced the deposition of C3c in infarct zone. Conclusion sCR1-SCR15-18 protein exerts cardioprotective effects in this rat I/R model.