解除大鼠腹主动脉缩窄逆转左心室肥厚的形态学观察

目的通过解除大鼠腹主动脉缩窄逆转左心室肥厚,并比较逆转后大鼠心脏和左心室肥厚心脏及正常大鼠心脏的形态学、胶原容积分数和凋亡指数的差别。方法雄性SD大鼠75只,随机分为正常组(n=15)、缩窄组(n=30)和解除缩窄组(n=30)。缩窄组和解除缩窄组行第1次手术通过缩窄腹主动脉方法建立左心室肥厚模型。术后第5周确认动物模型成功后,解除缩窄组大鼠行第2次手术解除腹主动脉狭窄。采用心脏超声、常规病理和定量病理等多种技术方法,对各组大鼠在第1次手术(腹主动脉缩窄)后第5周、第2次手术(解除缩窄)后第4周行形态学观察及形态学定量分析。结果腹主动脉缩窄后第5周,大鼠室间隔舒张期末厚度、左心室后壁舒张期末厚度显著增厚;心脏质量指数、左心室质量指数、心肌胶原容积分数、心肌凋亡指数显著增加;解除缩窄后的第4周,解除缩窄组大鼠上述指标显著下降,但仍高于正常组。结论通过解除大鼠腹主动脉缩窄可以部分逆转左心室肥厚,大鼠心脏形态、心肌胶原容积分数、凋亡指数有明显改善,但与正常大鼠仍有差异。

Morphological Observation of the Reversal of Ventricular Hypertrophy in Rat by Loosening Abdominal Aortic Banding

Aim To confirm the effects of left ventricular hypertrophy reversed by loosening abdominal aortic banding,and observe the changes of cardiac morphology,myocardial collagen volume fraction(CVF) and myocardial apoptotic index(AI).Methods 75 SD rats were randomly divided into the normal group(N group,n=15),abdominal aortic banding group(AAB group,n=30) and loosening abdominal aortic banding group(LAAB group,n=30).AAB and LAAB group received the first operation of narrowing the abdominal aorta to establish left ventricular hypertrophy model in rat.After 5 weeks,the LAAB group received the second operation of removing the abdominal aorta banding.After 5 weeks of the first operation and after 4 weeks of the second operation,heart mass index(HMI),left ventricular mass index(LVMI),interventricular septum thickness of end-diastolic(IVSTd),left ventricular posterior wall thickness of end-diastolic(LVPWTd),myocardial CVF and myocardial AI of three groups of rats were observed by general observation,ultrasonic cardiogram,myocardial Masson staining,myocardial tunel staining.Results HMI,LVMI,IVSTd,LVPWTd,myocardial CVF and myocardial AI were significantly increased in AAB group.After 4 weeks of removing the abdominal aorta banding,HMI,LVMI,IVSTd,LVPWTd,myocardial CVF and myocardial AI of LAAB group were significantly decreased compared with AAB group,but still higher than N group.Conclusion Loosening abdominal aortic banding could partly reverse the left ventricular hypertrophy.