阿托伐他汀逆转腹主动脉缩窄型高血压大鼠心肌重构的机制

The Mechanism of Atorvastatin Reverse Myocardic Remodel in the Hypertensive Rats with Abdominal Aortic Constriction

目的观察阿托伐他汀对腹主动脉缩窄型高血压大鼠血清血管紧张素(1-7)浓度及左心室肥厚心肌组织中p-ERK1/2表达水平的影响,探讨阿托伐他汀逆转心肌重构的可能机制。方法 50只SD雄性大鼠随机分为5组:假手术组、模型组、10mg/(kg.d)阿托伐他汀组、30mg/(kg.d)阿托伐他汀组及缬沙坦组,每组10只。术后第1天,将阿托伐他汀研磨成粉,溶于少量蒸馏水中制成悬液,采用灌胃法给药;假手术组和模型组大鼠均用等量生理盐水灌胃。每日上午定时一次,共4周。鼠尾容积法测定药物干预前及干预后2周、4周的血压变化。4周后处死大鼠,测定大鼠体重、左心室重量、左心室重量指数;HE染色检测心肌细胞平均直径;酶联免疫吸附法测定血清血管紧张素(1-7)浓度;免疫印迹法检测心肌p-ERK1/2蛋白表达水平。结果 30mg/(kg.d)阿托伐他汀组和10mg/(kg.d)阿托伐他汀组收缩压明显低于模型组(P<0.01),30mg/(kg.d)阿托伐他汀组收缩压明显低于10mg/(kg.d)阿托伐他汀组(P<0.01),缬沙坦组收缩压明显低于30mg/(kg.d)阿托伐他汀组和10mg/(kg.d)阿托伐他汀组(P<0.01);假手术组、30mg/(kg.d)阿托伐他汀组、10mg/(kg.d)阿托伐他汀组及缬沙坦组左心室重量指数明显低于模型组(P<0.01),30mg/(kg.d)阿托伐他汀组左心室重量指数明显低于10mg/(kg.d)阿托伐他汀组(P<0.05);假手术组、30mg/(kg.d)阿托伐他汀组及缬沙坦组心肌细胞平均直径明显低于模型组(P<0.01),10mg/(kg.d)阿托伐他汀组与模型组无差异(P>0.05);10mg/(kg.d)阿托伐他汀组、30mg/(kg.d)阿托伐他汀组及缬沙坦组血清Ang-(1-7)浓度显著高于模型组(P<0.01),30mg/(kg.d)阿托伐他汀组及缬沙坦组血清Ang-(1-7)浓度明显高于10mg/(kg.d)阿托伐他汀组(P<0.05);10mg/(kg.d)阿托伐他汀组、30mg/(kg.d)阿托伐他汀组及缬沙坦组p-ERK1/2蛋白表达水平显著低于模型组(P<0.01),但高于假手术组。结论阿托伐他汀对腹主动脉缩窄型高血压大鼠心肌重构具有逆转作用,其机制与降低压力负荷诱导的心肌肥厚组织中p-ERK1/2蛋白表达水平有关。

Aim To investigate the effect of atorvastatin on serum Ang（1-7）concentration and p-ERK1/2 protein expression level in left ventricular hypertrophic myocardium in the hypertensive rats with abdominal aortic constriction,and to explore the underlying mechanism.Methods Fifty adult male SD rats were randomly divided into following five groups（n=10）：sham group,model group,10 mg/（kg·d）atorvastatin group,30 mg/（kg·d）atorvastatin and 20 mg/（kg·d）valsartan group.Drugs were dissolved in physiological saline and orally administrated by gavage from day 1 after operation until four weeks.Systolic blood pressure（SBP）was taken before and after administration by 2 weeks and 4 weeks by tail-cuff method.Rats were sacrificed after 4 weeks,and body weight（BW）,left ventricular weight（LVW）,left ventricular weight index（LVWI）were measured;the average diameter of cardiomyocytes were measured and the changes of cardiac histopathology were observed by HE staining;serum Ang（1-7）concentration was determined by enzyme-linked immunosorbent assay（ELISA）;p-ERK1/2 protein expression level in myocardic tissue was detected by Western blotting.Results SBP in 10 mg/（kg·d）and 30 mg/（kg·d）atorvastatin group were significantly lower than that in model group（P〈0.01）;SBP in 30 mg/（kg·d）atorvastatin group was significantly lower than that in 10 mg/（kg·d）atorvastatin group（P〈0.01）;SBP in valsartan group was significantly lower than that in 10 mg/（kg·d）and 30 mg/（kg·d）atorvastatin group（P〈0.01）.Compared with model group,LVWI was markedly higher than that among sham group,30 mg/（kg·d）atorvastatin group and valsartan group（P〈0.01）.LVWI in 30 mg/（kg·d）atorvastatin group was markedly lower than that in 10 mg/（kg·d）atorvastatin group（P〈0.05）.Compared with model group,mean diameter of cardiomyocytes were significantly higher than that among sham group,30 mg/（kg·d）atorvastatin group and valsartan group（P〈0.01）;there was no difference of average diameter of cardiac myocytes between 10 mg/（kg·d）atorvastatin group and model group（P〉0.05）.Serum Ang（1-7）concentration in model group were markedly lower as compared to that among 10 mg/（kg·d）atorvastatin group,30 mg/（kg·d）atorvastatin group and valsartan group（P〈0.01）.Serum Ang（1-7）concentration in 30 mg/（kg·d）atorvastatin group and valsartan group were markedly higher as compared to that in 10 mg/（kg·d）atorvastatin group（P〈0.05）.Compared with model group,the expression of p-ERK1/2 protein among 10 mg/（kg·d）atorvastatin group,30 mg/（kg·d）atorvastatin group and valsartan group were significantly downregulated（P〈0.01）,but higher than that in sham group.Conclusion Atorvastatin can reverse myocardic remodel in the hypertensive rats with abdominal aortic constriction,which may be related to reducing p-ERK1/2 protein expression level in pressure overload-induced cardiac hypertrophy tissue.