瑞芬太尼后处理对犬心肺转流后心肌缺血-再灌注损伤的影响

目的研究瑞芬太尼后处理对心肺转流(CPB)犬缺血-再灌注心肌的保护作用及机制。方法 18只成年雄性犬,随机均分为缺血-再灌注组(C组)、缺血后处理组(I组)和瑞芬太尼后处理组(R组)。建立犬CPB模型,阻断升主动脉血流60min。主动脉阻断55min时自主动脉根部进行温血再灌注;I组在开放主动脉之前给予开放30s/再阻断30s三个循环;R组随温血输注瑞芬太尼4μg·kg-1·min-1,持续5min。测定CPB前5min(T0)、开放升主动脉5min(T1)、停CPB30min(T2)和120min(T3)时血浆肌钙蛋白I(cTnI)、丙二醛(MDA)浓度和超氧化物歧化酶(SOD)活性,停CPB120min后测定心肌含水率并观察心肌组织超微结构改变。结果与T0时比较,T1～T3时三组血浆cTnI和MDA浓度均明显升高(P<0.01),而SOD活性明显降低(P<0.01)。T1～T3时I组和R组cTnI和MDA浓度均低于C组(P<0.01),SOD活性高于C组(P<0.01)。I组和R组心肌含水率和超微结构改变均低于或轻于C组(P<0.01),I组和R组各指标差异无统计学意义。结论瑞芬太尼后处理减轻犬CPB后心肌缺血-再灌注损伤,其机制可能与减少活性氧生成并增加SOD活性进而减轻氧化应激有关。

Effects of remifentanil-postconditionging on myocardial ischemia-reperfusion injury after cardiopulmonary bypass in dogs

Objective To study the effect of remifentanil-postconditioning on ischemia-reperfusion myocardium after cardiopulmonary bypass (CPB) in dogs and its potential mechanism.Methods Eighteen adult male dogs were equally randomized into ischemia-reperfusion group (group C), ischemia-postconditioning group (group I) and remifentanil-postconditioning group (group R). After CPB model was established, the ascending aorta were occluded for 60 min. At 55 min of aortic cross-clamping, warm-blood perfusion from aortic root was performed; after 60 min of aortic occlusion, reperfusion was initiated for 30 s followed by 30 s of reocclusion, repeated for three cycles in I group; remifentanil (4 μg·kg-1·min-1) were continuously infused for 5 min with the warm blood in R group. Femoral artery blood samples were taken at 5 min before CPB (T0), 5 min after aortic cross-clamping release (T1), 30 min (T2) and 120 min (T3) after CPB for measuments of troponin I (cTnI) and malondialdehyde (MDA) contents and superoxide dismutase (SOD) activity, and the edema as well as ultrastructural changes of myocardium were analyzed after 120 min of CPB.Results The plasma contents of cTnI and MDA were significantly increased, and the SOD activity were significantly decreased at T1-T3 as compared with T0 in three groups (P<0.01). In groups I and R, the plasma concentration of cTnI and MDA were lower than C group (P <0.01), SOD activity were higher than C group (P<0.01) at the point of T1-T 3. Compared with group C, the water content and ultrastructural changes of myocardium were less (P <0.01) in groups I and R. There was no significant differences between groups I and R.Conclusion Remifentanil-postconditioning reduces myocardial ischemia-reperfusion injury after CPB in dogs, which may be induced by the reduced oxidative stress via decreasing reactive oxygen species generation and increasing SOD activity.