依那普利或氯沙坦对SHR左室肥厚和心肌纤维化的影响

The Effects of Enalapril and Losartan on Left Ventricular \;Hypertrophy and Myocardial Fibrosis in SHR

目的 :观察自发性高血压大鼠 (SHR)左室肥厚和心肌纤维化各指标的改变 ,以及依那普利和氯沙坦的保护作用。方法 :雄性 SHR(n=30 )自第 1 0周始服用依那普利 (2 0 mg.kg- 1 .d - 1 ) ,或氯沙坦 (2 5 mg.kg - 1 .d - 1 ) ,或二者合用 (依那普利1 0 mg.kg - 1 .d - 1 ,氯沙坦 1 2 .5 mg.kg - 1 .d - 1 )至第 1 6周 ,并以年龄、性别、数量配对的未治疗 SHR和 Wistar- kyoto(WKY)大鼠作对照。测定收缩压 (SBP)、左室重量 (L VM)以及左室重量指数 (L VMI)和左室心肌胶原含量 ;计算机图象分析心肌细胞大小、心肌胶原容积分数 (CVF)和血管周围胶原面积(PVCA)。结果 :SHR的 SBP、L VM、L VMI、心肌胶原含量、心肌细胞的横截面积、CVF和 PVCA均显著高于 WKY对照组 (P<0 .0 0 1 )。 SHR治疗组上述指标显著低于 SHR未治疗组 (P<0 .0 1 ) ,依那普利与氯沙坦之间无显著差别 (P<0 .0 5 )。二者合用比单用依那普利或氯沙坦更有效 (P<0 .0 5 )。结论 :依那普利和氯沙坦可显著的降低血压、逆转 SHR早期左室肥厚和心肌纤维化 。

Aim:To investigate the left ventricular hypertrophy and myocardial fibrosis in spontaneously hypertensive rats(SHRs),and the protective role of enalapril and losartan. Methods:Enalapril(20 mg·kg 1 ·d 1 ) or losartan(25 mg·kg 1 ·d 1 ) or their combination(enalapril 10 mg·kg 1 ·d 1 ,losartan 12.5 mg·kg 1 ·d 1 ) was administered from 10 to 16 weeks of age of SHRs( n= 30).Male,age matched untreated SHR and Wistar Kyoto(WKY) rats were served as controls.Systolic blood pressure(SBP), left ventricular mass and left ventricular mass index(LVMI) were determined.Left ventricular collagen contents were measured by spectrophotometric method.Cardiomyocytes size,the parameter and content of collagen on pathological tissue slices were assessed with computerized video processing. Results:Compared with WKY rats,the SBP,LVMI,left ventricular collagen contents,cardiomyocytes size,collagen volume fraction(CVF) and perivascular circumferential collagen area(PVCA) were significantly increased in SHRs( P <0.001),and substantially reduced in treated SHRs than that in untreated SHRs( P <0.01).There were no difference in these parameters between enalapril group and losartan group.Except the SBP, the combination of enalapril with losartan reduced all markers more pronouncedly than enalapril or losartan alone. Conclusion:Enalapril and losartan decrease blood pressure,reverse early left ventricular hypertrophy and myocardial fibrosis in SHR. Little difference of effects has been found between them. The combination of enalapril with losartan is more effective than monotherapy except effect on the SBP.