手术逆转压力负荷性左心室肥厚的实验研究

Experimental study on reversing pressure overload-induced left ventricular hypertrophy by surgery

目的:探讨外科手术逆转压力负荷性左心室肥厚的有效性。方法:75只SD大鼠随机分为正常组(n=15)和肥厚组(n=60),后者行腹主动脉缩窄术造成左心室肥厚;肥厚组存活大鼠再随机分为实验组(n=26)和对照组(n=20),实验组大鼠再次手术解除腹主动脉的缩窄,术后每周取血液标本检测血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)和醛固酮(aldosterone,Ald)含量,取心脏标本测心脏质量指数(heart mass index,HMI)和左心室质量指数(left ventricular mass index,LVMI),并行HE染色分析。实验第9周行超声心动图测舒张末期左室后壁厚度(leftventricular posterior wall thickness of end-diastolic,LVPWTd)和舒张末期室间隔厚度(interventricular septum thicknessof end-diastolic,IVSTd)。结果:实验组AngⅡ和Ald水平分别于实验第8周和第9周相比对照组明显下降(P<0.01),接近正常组水平。实验组HMI和LVMI实验第9周相比对照组下降(P<0.05),但较正常组仍明显肥厚(P<0.01)。实验组LVPWTd实验第9周较对照组下降(P<0.05),仍厚于正常组(P<0.05)。结论:外科手术可以逆转腹主动脉缩窄导致的压力负荷性左心室肥厚。

Objective To explore the effect of surgery on reversing pressure overload-induced left ventricular hypertrophy. Methods Seventy-five SD rats were randomly divided into a normal group and a myocardial hypertrophy group,which were induced by banding the abdominal aorta.The survived rats in myocardial hypertrophy group were further divided into a control group and a experimental group.The rats in experimental group were subjected to relieve abdominal aorta banding.The blood samples were taken for the measurement of the levels of angiotensinⅡ（AngⅡ） and aldosterone（Ald） every week after surgery.The heart samples were taken to examine heart mass index（HMI） and left ventricular mass index（LVMI）,and carried out hematoxylin-eosin（HE） staining in the same.Ultrasonic cardiogram was conducted to measure the interventricular septum thickness of end-diastolic（IVSTds） and left ventricular posterior wall thickness of end-diastolic（LVPWTds） at the 9th week. Results The AngⅡ and Ald contents in the experimental group were significantly lower than that in the control group respectively at the 8th or 9th week（P0.01）.The HMI and LVMI in the experimental group were decreased compared with that in the control group at the 9th week（P0.05）,but significantly higher than that in the normal group（P0.01）.The LVPWTds in the experimental group were decreased compared with that in the control group at the 9th week（P0.05）,but still higher than that in the normal group（P0.05）. Conclusion The surgery treatment can successfully reverse pressure overload-induced left ventricular hypertrophy.