硬膜外注射吗啡对兔急性缺血再灌注心肌细胞凋亡的影响

Effects of epidural injection of morphine on apoptosis of myocardial acute ischemia and reperfusion in rabbits

目的探讨硬膜外注射吗啡对兔心肌急性缺血再灌注损伤的保护作用。方法采取开胸结扎左前降支(LAD)的急性心肌梗死模型。新西兰兔22只随机分成2组:①硬膜外吗啡组:经硬膜外注入吗啡(0.25 mg/kg,配成0.5 ml溶液);②对照组:经硬膜外注入生理盐水0.5 ml。再灌注4 h后取缺血部分心肌,用TUNEL法检测每200个心肌细胞细胞凋亡数。结果硬膜外吗啡组凋亡细胞数明显低于对照组(60.6±7.5 vs 85.7±9.2),差异有统计学意义(P<0.05)。硬膜外吗啡组和对照组细胞凋亡百分比分别为30.3%和42.5%,差异有统计学意义(P<0.05)。结论硬膜外注射吗啡能减少缺血再灌注心肌细胞凋亡的数量,对缺血再灌注心肌有明显的保护作用。

Objective To investigate the protective effects of epidural injection of morphine in the rabbit model of acute myocardial ischemia and repeffusion injury in respect of myocardial infarct size, myocardial cell apoptesis and the left ventricular function. Methods Twenty- two rabbits were divided randomly into two groups：epidural morphine group and control group. Either morphine（0.25 mg/kg, 0.5 ml） or normal saline 0.5 ml was injected epidurally in corresponding group over a period of 20 min before coronary artery occlusion. After a fourhour repeffusion, a slice of myocardial tissue was taken from the risk zone for apoptotic myocyte count in 200 myocardial cells （TUNEL） .Resuils The apoptotic myocyte count in the epidural morphine group was lower than that in the control group（60.6 ± 7.5 vs 85.7 ± 9.2）, the difference being statistically significant （ P 〈0.05）. The percentages of the apoptotic myocytes were 30.3% in the epidural morphine group and 42.5 % in the control group, with a statistically significant difference （ P 〈 0.05）. Conclusion Epidural injection of morphine reduces the apoptotic myocyte count,effectively protecting the myocardium from the injury of infarction and repeffusion.