卡维地洛对大鼠缺血再灌注心肌损伤及β_1受体密度的影响

The effect of Carvedilol on ischemia/reperfusion myocardial injury and β_1-adrenergic receptor density

目的 观察卡维地洛对缺血再灌注心肌损伤及肾上腺素能β1受体密度的影响。方法40只大鼠均分二组,对照组开胸反复结扎放松左冠状动脉造成心肌缺血再灌注损伤。卡维地洛组于相同手术前5天,每天灌服卡维地洛5 mg/kg、2次/d。术后观察心电图ST段变化和心律失常情况,测血清肌酸激酶和心肌钙含量并采用高选择性β1受体拮抗剂3H-CGP放射配基结合法测定心肌匀浆β1受体密度。结果 卡维地洛组心电图ST1+aVL+V3(29.3±5.2)mm,明显低于对照组(33.6±7.6)mm,P=0.0435;每个时间段平均心律失常级别(1.25±0.36)级,低于对照组(1.65±0.62)级,P=0.0171;血清肌酸激酶值(1123.6±323.4)U/L,低于对照组(1452.4±364.2)U/L,P=0.0045;心肌组织钙含量(56.3±9.1)μg/g,低于对照组(68.4±7.5)μg/g,P<0.0001;心肌β1受体密度(245.8±37.0)cpm,低于对照组(295.4±24.6)cpm,P<0.0001。结论 服用β受体阻滞剂卡维地洛可以降低缺血再灌注心肌β1受体密度,减轻心电图ST段抬高和心律失常,降低心肌钙含量并减少心肌酶的释放。

Objective To observe the effect of carvedilol on myocardial injury and β1-adrenergic receptor density in ischemia/reperfusion heart. Methods Forty rats were equally divided into two groups. In control group, the left coronary artery was ligated and relaxed repeatedly to cause ischemia/ reperfusion myocardial injury. In carvedilol group, the rats were treated with carvedilol 5 mg/kg, twice a day, for 5 days before the operation. Electrocardiogram ( ECG) , serum creatine kinase and myocardial calcium concentration were observed. The myocardial β1 receptor density was measured by highly selective p, adrenoceptor radioligand 3H-CGP. Results Myocardial β1 receptor density (245. 8 ±37. 0) cpm in carvedilol group was lower than control group (295. 4 ±24. 6) cpm, P <0. 0001. ECG STI + aVL + V3 segment (29. 3 ±5. 2) mm vs. (33.6 ±7. 6) mm, P= 0.0435; arrhythmia score 1.25 ±0.36 vs. 1.65 ±0. 62,P =0. 0171; serum creatine kinase (1123. 6 ± 323.4) U/L vs. (1452.4 ±364.2) U/L, P = 0.0045; and myocardial calcium concentration (56. 3 ±9. 1) μg/g vs. (68. 4 ±7. 5) μg/g, P <0. 0001; were lower in carvedilol group than in control group respectively. Conclusion Carvedilol can reduce myocardial injury and myocardial β1 receptor density in ischemia/reperfusion injury heart.