Effects of Zhenwu decoction on rats with pressure-overloaded left ventricular myocardial hypertrophy XIE

Abstract

Objective To investigate the effects of Zhenwu decoction (a herbal preparation made in a form of instant granules readily soluble into decoction to administer) on rats with chronic pressure-overloaded left ven-tricular hypertrophy. Method All the male SD rats were randomly(random number) divided into 3 groups: sham operation group (n= 8), operation group (n= 15) and herbal medicine group (n= 15). The model of myocar-dial hypertrophy was made by gradually constricting the abdominal aorta. After 16 weeks, cardiac ultrasonography was used in rats of all groups to ascertain the post-operational left ventricular (LV) hypertrophy established. And the Zhenwu decoction was added in the herbal medicine group in a dose of 12 g/kg mixed in feedstuff fed for 8 weeks. After 24 weeks, the weight and structure as well as function of the heart of rats in each group were mea-sured by high-frequency ultrasonography, and Massion stain was performed on cardiac muscles. Meanwhile, both the total collagen volume fraction (CVF-T) and non-coronary vessel collagen volume fraction (CVF-NV) were ana-lyzed. Results There was an increase in the weight of the heart with a predominance of the left ventricle in the operation group (P ＜ 0.05) . The heart was enlarged with diastolic interventricular septum thickness (IVSt) and left ventricular posterior wall thickness (LVPWt) increased predominantly (P ＜ 0.01). There was a significant decrease in cardiac function (P ＜ 0.05). In herbal medicine group, both the weight and volume of heart were lower than those in operation group with predominance of IVSt and systolic left ventricular wall (P ＜ 0.01 both).And the cardiac function of rats in herbal group was better (P ＜ 0.05). Interstitial and collagen hyperplasia increased significantly in the rats of operation group found by pathological analysis. In herbal medicine group, the pathological changes were blunted in varied magnitude with significant decrease in CVF-T and CVF-NV in compari-son with operation group (P＜0.01), and no difference in those was found compared with sham operation group (P＞ 0.05) . Conclusions The Zhenwu decoction could minimize the hyperplasia changes of heart in rats with pressure-overloaded left ventricular hypertrophy, maintaining the normal cardiac function. Key words: Zhenwu decoction; Heart failure; Ventricular reconstruction; Hypertrophy; Pressure load; Massion stain; Myocardial collagen fiber; Abdominal aorta constriction