失血预适应对大鼠心肌缺血-再灌注损伤的保护作用

Protective effects of preconditioning phlebotomy against myocardial ischemia-reperfusion injury in rat

目的评价失血预适应对大鼠心肌缺血/再灌注损伤的保护作用,并探索降钙素基因相关肽(calcitonin gene-related peptide, CGRP)所起的作用。方法将60只雄性SD大鼠随机分为三组:对照组、失血组、多抗组。每组均行30 min缺血-2 h再灌注。失血组在失血15 min后行缺血/再灌注。多抗组在失血前静注CGRP多抗(2.5 mg/kg·b.w.)。坏死区(IS)用NBT染色确定。梗死大小用IS占危险区(AAR)的百分数表示。结果失血组的血浆CGRP浓度均较对照组和多抗组显著为高(F=12.4, P=0.032-0.005)。失血组的IS(F=52.4, P<0.001)和IS/AAR(F=43.7, P<0.001)均较对照组和多抗组显著为低,多抗组的IS(P=0.0001)和IS/AAR(P=0.0001)也较对照组显著为低。结论失血预适应对大鼠心肌缺血/再灌注损伤具有显著的保护作用,CGRP在其中起一定的作用。

Objective To investigate the protective effect of preconditioning phlebotomy against ischemia-reperfusion injury and the role of calcitonin gene-related peptide (CGRP) in this protection mechanism. Methods Sixty SD rats were randomly assigned in equal number into control, phlebotomy, and CGRP polyclonal antibody (PcAb) groups, all of which were subjected to 30 min regional ischemic followed by two-hour reperfusion, initiated 15 min after phlebotomy in the latter 2 groups. The rats in CGRP PcAb group were given the antibody (2.5 mg/kg) before phlebotomy. After the operations, plasma CGRP level was determined in 8 rats from each group by radioimmunoassay, and the infarct size (IS) by nitro blue tetrazolium, represented as percentage of the area at risk (AAR). Results The mean plasma CGRP level was significantly increased in phlebotomy group compared with the levels in control and PcAb groups (F=12.4, P=0.032-0.005), and a significant reduction in IS (F=52.4, P<0.001) and IS/AAR (F=43.7, P<0.001) occurred in phlebotomy group. Conclusion Preconditioning phlebotomy has obvious cardioprotective effect against ischemia-reperfusion injury, in the mechanism of which CGRP may play a role.