两种剂量异丙肾上腺素制备心衰大鼠模型心功能的比较

目的比较两种剂量异丙肾上腺素（isoproterenol,ISO）制备的大鼠心衰模型心功能的特点。方法用3 mg/（kg·d）和5 mg/（kg·d）两种剂量、连续3 d腹腔注射ISO制备两组心衰大鼠模型,并用等量生理盐水同方法制备对照组。5周后,比较各组大鼠存活率,并用Doppler超声心动图比较其反映心功能的各项参数。结果大、小剂量组的存活率分别为48%及68%。左室后壁、室间隔厚度及射血分数、心输出量随ISO剂量的增加而增厚及减少。小剂量组心率维持正常,而大剂量组明显下降。结论ISO 3 mg/（kg·d）使用5周即可达心衰程度,成活率高;而5 mg/（kg·d）组心衰更为严重,尽管存活率尚可,但明显低于前者。该试验为ISO建立心衰动物模型提供了有效的用药剂量。同时也进一步证实了Doppler超声心动图是检测各种动物心功能的一种简便、无创及可靠的操作方法。

Comparison of cardiac function in rat heart failure models induced by different doses of isoproterenol

Objective To compare the cardiac function in rat heart failure models induced by different doses of isoproterenol （ISO）. Methods Rats were injected intraperitoneally with isoproterenol at 3 mg/（ kg · d） and 5 mg/（ kg · d）for 3 consecutive days to establish heart failure models. Meanwhile, the control group was established by intraperitoneally injecting same volume of normal saline. Five weeks later, rat survival rates were compared, and the cardiac function tests were performed by using Doppler echocardiography procedures. Results Survival rates of high and low dose groups were 48% and 68%, respectively. The more ISO was injected, the lower were the ejection fraction and cardiac output. Heart beats in animals of the low dose group remained normal, but decreased sharply in animals of the high dose group. Conclusion Both high or low dose isoproterenol can induce rat heart failure in this experiment, but the cardiac function in animals of the high dose group is much worse. This experiment provides an optimal dose to establish rat heart failure models. Meanwhile, Doppler echocardiography offers a simple, atraumatic and reliable way to test cardiac function in rats.