Abstract: ObjectiveTo observe the protective effect and mechanism of Radix astragali on cardiac function of rats with heart failure due to abdominal aorta coarctation. MethodsEighty male Sprague-Dawley(SD) rats weighing 200-220 g were used.Twenty rats were randomly assigned as sham group.The remainder were underwent surgery for abdominal aorta coarctation and randomly divided into the model,Radix astragali and captopril groups,followed by a 8-week treatment with Radix astragali(2 g/kg per day,intraperitoneal injection) or captopril (100 mg/kg per day,drinking water) once a day for 8 weeks.The rats in sham and model group were injected with equal volume of physiological saline.Eight weeks after the treatment,haemodynamic performance of the survivals were measured to assess the cardiac function.The mass of whole heart and left ventricular were determined accurately and the cardiac mass index(CMI) and left ventricular mass index(LVMI) were calculated.Immunohistochemistry procedure was used to detect the expression of caspase-3 in rat cardiac tissues. ResultsLVMI of Radix astragali and captopril groups were significantly lower than that of model group (P<0.01).Cardiac function of Radix astragali and captopril groups were improved.Left ventricular systolic pressure (LVSP),maximum rate of rise/decrease of LVSP(+dP/dtmax,-dP/dtmax) were obviously increased (P<0.05),while left ventricular end-diastolic pressure (LVEDP) was decreased dramatically than that in the model group(P<0.05).The expression of caspase-3 was decreased and gray value was higher significantly in the Radix astragali and captopril groups than that in the model group(P<0.05). ConclusionThe protective effect of Radix astragali on cardiac function and myocardium hypertrophy of rats with heart failure may result from inhibiting apoptosis of myocardial cells.