中期因子对大鼠心肌梗死后心室重构及心功能的影响

目的探讨外源性中期因子(MK)对心肌梗死后大鼠心室重构及心功能的影响。方法建立急性心肌梗死(AMI)雄性Wistar大鼠模型45只,随机分为AMI对照组、MK治疗组、假手术组,每组各15只;造模成功后1μg/200g人重组中期因子在梗死周围分5点注射给药。4周后检测血液动力学及心功能参数,心脏标本检测左室质量及左室质量指数(LVMI)、心肌梗死面积,并检测血浆和心肌血管紧张素Ⅱ(AngⅡ)水平。结果与假手术组相比较,AMI对照组左室质量及左室质量指数、左室截面直径及心肌AngⅡ水平明显增高,而左室收缩压(LVSP)及左室内压最大上升和下降速率(±dp/dt)均明显降低(均P<0.01);与AMI组相比较,MK治疗组左室质量及左室质量指数、左室截面直径明显降低(P<0.05或P<0.01),LVSP和±dp/dt均明显增高(P均<0.05),心肌梗死面积和心肌AngⅡ水平也明显低于AMI组。结论外源性的MK应用能减轻AMI后心室重构,可保护心功能。

Midkine on ventricular remodeling and cardiac function in rats with acute myocardial infarction

Objective To study the effect of midkine（MK） on left ventricular（LV） remodeling and cardiac function in rats with acute myocardial infarction（AMI） . Methods Forty-five male Wistar rat models with AMI were established and randomized to either AMI control group,or MK treatment group,or sham-operated group（n=15 rats each） . Injection of 1 μg/200 g recombinant human MK was performed to each rat over the border zone myocardium at five sites after model establishment. Four weeks later,haemodynamic indexes and cardiac function indexes were detected,and so were the left ventricular weight（LVW） ,left ventricular mass index（LVMI） of heart preparation,myocardial infarct size,AngⅡ in plasma and cardiac muscle were measured. Results Compared with sham-operated rats,LVW,LVMI,left ventricular section and myocardial angiotensin Ⅱ level were significantly increased while the LV systolic pressure（LVSP） ,the maximum rising and dropping rates of LV pressure（±dp/dt） significantly decreased in AMI control group（all P0.01） . Compared with AMI control group,LVW,LVMI and left ventricular section in MK treatment group were significantly decreased（P0.05 or P0.01） ,besides,LVSP and ±dp/dt were significantly increased（P0.05） ,and myocardial infarct size and myocardial angiotensin Ⅱ level were significantly lower than AMI group. Conclusion Extrinsic MK is effective in attenuating left ventricular remodeling and protecting cardiac function.