肾上腺皮质激素反应在心肌缺血预适应保护中的作用

Effect of cortisol on ischemic preconditioning in rabbit hearts

目的:探讨肾上腺皮质激素反应在心肌缺血预适应保护中的作用。方法:30只家兔随机分为5组,缺血预适应组(IPC),缺血再灌注组(IR),依托咪酯组(Etom),甲基强的松龙组(MP)和对照组(control),以心肌梗死面积/缺血面积,血清肌酸激酶(CK)活性,肌钙蛋白I(cTnI)浓度为检测指标,同时检测血清皮质醇动态变化。结果:IPC组、Etom组、IR组、MP组心肌梗死面积/缺血面积分别为5.9%±2.8%,11.3%±3.6%,26.8%±4.5%,18.2%±3.7%,CK活性增高值分别为(255±89)U/L,(314±160)U/L,(855±371)U/L,(768±404)U/L,cTnI增高值分别为(3.6±0.6)μg/L,(5.9±2.0)μg/L,(8.1±3.6)μg/L,(6.1±2.3)μg/L。各指标组间比较均有统计学意义(P<0.01)。Etom组皮质醇反应明显钝化。结论:钝化皮质醇反应可明显削弱IPC的保护作用,甲基强的松龙有一定程度心肌保护作用,提示IPC保护作用中可能有应激反应成分参与。

Objective To determine the effects of reacting cortisol on ischemic preconditioning （IPC）. Methods Thirty rabbits were randomized into ischemic preconditioning （IPC） group, etomidate （Etom） group, ischemic/reperfusion （IR） group, methylprednisolone （MP） group and a control group. The ratios of infarction size versus risk area （ Infarct/Risk ） were calculated. The elevations of serum CK activity and cTnI concentrations as well as serum cortisol concentrations were measured. Results The ratios of Infarct/Risk were 5.9%±2.8% for IPC,11.3%±3.6% for Etom,26.8% ±4.5% for IR and 18.2%±3.7% for MP. The elevations of serum CK activity （U/L） were 255±89 for IPC,314±160 for Etom,855±371 for IR and 768±404 for MP,the elevations of serum cTnI concentrations （μg/L） were 3.6± 0. 6 for IPC, 5. 9 ±2. 0 for Etom, 8.1±3.6 for IR and 6. 1± 2.3 for MP. Those indicators among groups are all significantly different （P 〈 0.01 ）. Cortisol reacting was markedly diminished in Etom group. Conclusion A blunted cortisol reaction can markedly undermine the benefit of ischemic preconditioning, methylprednisolone show a certain myocardial protection. Cortisol may play an important role in the IPC process.