不同时点应用维拉帕米对心肌缺血再灌注损伤的保护作用

目的 观察不同时点应用维拉帕米(VP)对大鼠心肌缺血再灌注损伤的保护作用,并探讨其心肌保护的作用机制.方法 建立大鼠心肌缺血再灌注模型,将18只雄性SD大鼠随机分为3组,每组6只.Verapamil-1组于结扎前10 min开始泵入维拉帕米稀释液(0.25 mg/kg),Verapamil-2组于再灌前10 min开始泵入维拉帕米稀释液(0.25 mg/kg),IR组于结扎前10 min开始泵人生理盐水(2ml/kg).再灌注后60min处死大鼠.检测血清肌钙蛋白T(cTnT)含量、缺血区心肌组织Caspase-3表达水平;组织形态学分析心肌损伤程度.结果　Verapamil-1组血清cTnT含量、心肌组织Caspase-3表达量(4.60±1.12)ng/L,(39.51±5.01)%较IR组(7.70±1.31)ng/L,(51.10±5.30)%和Verapamil-2组(7.23±1.03)ng/L,(49.35±4.95)%明显降低,差异有统计学意义(P＜0.05);Verapamil-2组血清cTnT含量、心肌组织Caspase-3表达水平和IR组比较差异无统计学意义(P＞0.05);Verapamil-1组心肌组织形态学损伤程度较IR组和Verapamil-2明显降低,差异有统计学意义(P＜0.05);Verapamil-2组心肌组织形态学损伤程度和IR组比较差异无统计学意义(P＞0.05).结论　结扎前10 min开始给予维拉帕米对心肌缺血再灌注损伤有明显保护作用,再灌注前10 min开始给予维拉帕米对心肌缺血再灌注损伤无保护作用.

Abstract：

Objective To investigate the effect of verapamil administered at different time points on myocardial ischemia-reperfusion injury in rats, and explore the mechanism of myocardial protection.Methods The model of myocardial ischemia reperfusion in rats was established and 18 male SD rats were randomly divided into 3 groups,n =6 each. Verapamil dilution (0. 25 mg/kg) was pumped into verapamil1 group 10 min before ischemia, and verapamil dilution (0. 25 mg/kg) was pumped into verapamil-2 group 10 min before reperfusion. Normal saline (2 ml/kg) was pumped into IR group 10 min before ischemia.Rats were killed 60 min after reperfusion. The levels of serum cardiac Troponin T (cTnT) and the expression of myocardial Caspase-3 were evaluated. Histomorphological methods were used to analyze the extent of myocardial injury. Results The levels of serum cTnT and the expression of myocardial Caspase-3 in verapamil-1 group (4.60 ± 1.12) ng/L, (39.51 ±5.01)% were significantly lower than those in IR group (7. 70 ± 1.31 ) ng/L, (51.10 ±5. 30)% and verapamil-2 group (7. 23 ± 1.03) ng/L, (49. 35 ±4. 95 ) % ( P ＜ 0. 05 ). The levels of serum cTnT and the expression of myocardial Caspase-3 had no significant difference between verapamil-2 group and IR group (P ＞ 0. 05 ). The extent of myocardial injury in verapamil-1 group was significantly lower than that in IR group and verapamil-2 group (P ＜ 0. 05 ). The extent of myocardial injury had no significant difference between verapamil-2 group and IR group (P ＞0. 05). Conclusion Starting from 10 min before ischemia, verapamil has protective effects on myocardial ischemia/reperfusion injury. Starting from 10 min before reperfusion, verapamil does not provide protection on myocardial ischemia reperfusion injury.

Protective effect of verapamil administered at different time points on myocardial ischemia-reperfusion injury in rats

Objective To investigate the effect of verapamil administered at different time points on myocardial ischemia-reperfusion injury in rats, and explore the mechanism of myocardial protection.Methods The model of myocardial ischemia reperfusion in rats was established and 18 male SD rats were randomly divided into 3 groups,n =6 each. Verapamil dilution (0. 25 mg/kg) was pumped into verapamil1 group 10 min before ischemia, and verapamil dilution (0. 25 mg/kg) was pumped into verapamil-2 group 10 min before reperfusion. Normal saline (2 ml/kg) was pumped into IR group 10 min before ischemia.Rats were killed 60 min after reperfusion. The levels of serum cardiac Troponin T (cTnT) and the expression of myocardial Caspase-3 were evaluated. Histomorphological methods were used to analyze the extent of myocardial injury. Results The levels of serum cTnT and the expression of myocardial Caspase-3 in verapamil-1 group (4.60 ± 1.12) ng/L, (39.51 ±5.01)% were significantly lower than those in IR group (7. 70 ± 1.31 ) ng/L, (51.10 ±5. 30)% and verapamil-2 group (7. 23 ± 1.03) ng/L, (49. 35 ±4. 95 ) % ( P ＜ 0. 05 ). The levels of serum cTnT and the expression of myocardial Caspase-3 had no significant difference between verapamil-2 group and IR group (P ＞ 0. 05 ). The extent of myocardial injury in verapamil-1 group was significantly lower than that in IR group and verapamil-2 group (P ＜ 0. 05 ). The extent of myocardial injury had no significant difference between verapamil-2 group and IR group (P ＞0. 05). Conclusion Starting from 10 min before ischemia, verapamil has protective effects on myocardial ischemia/reperfusion injury. Starting from 10 min before reperfusion, verapamil does not provide protection on myocardial ischemia reperfusion injury.