阿托伐他汀对压力负荷心肌肥厚大鼠血管紧张素转换酶2表达的干预研究

目的:探讨血管紧张素转化酶2(angiotensin converting enzyme 2,ACE2)在压力负荷心肌肥厚大鼠中的表达以及阿托伐他汀干预对其的影响.方法:SD大鼠随机分为正常对照组(A组)、正常对照加阿托伐他汀组(B组)、假手术组(C组),其余2组通过不完全结扎大鼠腹主动脉构建心肌肥厚模型,并分为阿托伐他汀干预组(D组)[术前l周起灌胃给予5 mg/(kg·d )阿托伐他汀,直至术后4周]和非药物手术组(E组).术后4周检测大鼠左心室质量指数,组织切片染色后光镜检查,并测心肌细胞平均直径及胶原容积百分比,分别用实时RT-PCR法和Western免疫印迹法测定心肌组织中ACE2 mRNA和蛋白水平的表达.结果:E组左心室质量指数、心肌细胞平均直径及胶原容积百分比较A组、B组及C组均显著增加(P<0.01),并且ACE2 mRNA和蛋白表达显著增加(P<0.01).D组上述指标较E组显著下降(P<0.01).结论:心肌肥厚大鼠ACE2 mRNA和蛋白表达显著增加;阿托伐他汀能够有效地延缓压力负荷诱导的心肌肥厚,并能下调ACE2 mRNA和蛋白表达.

Effect of atorvastatin on ACE2 expression in pressure overload induced cardiac hypertrophy in rats

OBJECTIVE: To investigate the effect of atorvastatin on the expression of angiotensin converting enzyme 2 (ACE2) mRNA and its protein in hypertrophic myocardium in rats. METHODS: Suprarenal abdominal aortic coarctation was performed to create the pressure overload induced left ventricular hypertrophy model in rats. RESULTS: Rats were randomly divided into 5 groups: (1) normal control group (Group A); (2) normal control group treated with atorvastatin [(5 mg/(kg.dd), Group B]; (3) sham group (Group C); (4) atorvastatin given orally by gastric gavage for 4 weeks [5 mg/(kg.dd),Group D]; (5) vehicle group (Group E). Stained pathological section was observed under light microscope to measure cardiomyocyte diameter transversa and collagen volume fraction. ACE2 mRNA and its protein expression were detected by real-time RT-PCR and Western blot. Compared with Group A,B, and C, the left ventricular mass index, cardiomyocyte diameter transversa and collagen volume fraction in Group E increased statistically (P< 0.01), ACE2 mRNA and its protein expression also elevated remarkably (P< 0.01). Compared with Group E, the above mentioned indexes in Group D reduced significantly (P< 0.01). CONCLUSION: ACE2 mRNA and its protein expression increase significantly in hypertrophic myocardium in rats; atorvastatin can attenuate cardiac hypertrophy due to pressure overload in rats effectively, and part of this anti-hypertrophy effect may be attributed to decrease ACE2 mRNA and protein expression.