ABSTRACT
BACKGROUND:In the perspective of traditional Chinese medicine, few studies have focused on the compound preparations though there are many investigations. The present study was undertaken to investigate the effect of Zhenwu Tang Granule on chronic pressure-overloaded left ventricular hypertrophy in rats. METHODS:The study was performed at the laboratory of Guangzhou Institute of Respiratory Disease. Male SD rats were divided randomly into 3 groups:sham operation group (n=8), operation group (n=15) and traditional Chinese medicine (TCM) group (n=15).The model of myocardial hypertrophy was made by gradually constricting the abdominal aorta. Sixteen weeks later, cardiac ultrasonography was performed in all groups in order to ascertain post-operational left ventricular (LV) hypertrophy. And Zhenwu Tang Granule was added at a dose of 12 g/kg in the mixed feedstuff for 8 weeks in the TCM group. In the 24th week, weight, structure as well as function of the heart in each group were measured by high-frequency ultrasonography, and Masson's staining was performed on the cardiac muscles. Meanwhile, total collagen volume fraction (CVF-T) and non-coronary vessel collagen volume fraction (CVF-NV) were analyzed. RESULTS:There was an increase in the weight of the heart in the operation group, with the left ventricule dominated (P<0.05). The heart was enlarged, with diastolic interventricular septal distance (IVSd) and left ventricular posterior wal distance (LVPWd) dominated (P<0.01).There was a significant decrease in the cardiac function (P<0.05). The weight (P<0.01) and volume of the heart decreased in the TCM group compared with the operation group, with IVSd and systolic left ventricular posterior wal dominated (P<0.01). And the cardiac function was improved (P<0.05). Significant interstitial and col agen hyperplasia was shown in the operation group based on pathological analysis, and various improvements were proved in the TCM group, i.e. there was a significant decrease in CVF-T and CVF-NV (P<0.01) compared with the operation group; but no difference (P>0.05) was found when compared with the pseudo-operation group. CONCLUSION:Zhenwu Tang Granule could reduce the weight and volume of the heart, improve the cardiac function, inhibit hyperplasia of collagen, and reverse myocardial hypertrophy in rats with pressure-overloaded left ventricular hypertrophy.