Objective:To observe the effect of Zhimu and Huangqi on increasing heart rate and
cardiac hypertrophy,and its bradycardia
effect,to evaluate the exercise capacity and
response to stimulation and to discuss the use of Zhimu in treating heart failure. Method: ① Rats were treated with isoproterenol 1.25 μg·kg -1 ip,and then the increasing of heart rate and the bradycardia effect were measured after administrated with Zhimu or Huangqi for 3 days. ② Mice
cardiac hypertrophy model was established by s.c ISO 1 mg·kg -1 , 2 times per day for 14 days and heart weight index was measured after Zhimu and Huangqi was given orally alone or jointly for 14 days. ③ Abdominal aorta banding operation was done in mice and 3 weeks after operation,they were administrated for 2 weeks,and then run time(exercise capacity), quiet heart rate, ISO response heart rate after ip isoproterenol and heart weight index were measured. ④ Cardiac hypertrophy model (inject ISO 14 days) mice were administrated for 12 days, and the mortality and dying time of mice in cold (-20 ℃) and heat(45 ℃) stimulative condition were observed. Result: Zhimu could cut down the increasing of heart rate induced by ISO, decrease significantly heart weight index in cardiac hypertrophy mice, reduce the quiet heart rate and prolong the run time in abdominal banding model. Zhimu combined with Huangqi could also improve the ISO response in abdominal banding model mice, reduce the mortality and delay dying time of mice in stimulative condition. Conclusion: Zhimu combined with Huangqi can slow down heart rate, enhance the reserve force of the heart,and improve the response capacity of cardiac hypertrophy mice in stimulative condition.<