ABSTRACT
OBJECTIVE: To discuss the effect and mechanism of cinepazide maleate (CM) on myocardial injured rats induced by isoproterenol (Iso). METHODS: Fifty male and female rats were divided into normal group, model group, the low and the high dose group of the CM, and captopril (Cap)positive control group. The rat model of myocardial injury was established by subcutaneous injection of Iso (5 mg·kg-1·d-1)for 7 d, rats in treatment group were given intraperitoneal injection of CM on the second day (1.5, 3 mg·kg-1·d-1), rats in positive control group were given intragastric administration of Cap(10 mg·kg-1·d-1), and rats in normal group and model group were given intraperitoneal injection of normal saline in the same volume, for 14 d. The rats in each group were tested before and after treatment by three times of running endurance test. After stopping drug all rats were anesthetized for measuring the electrocardiogram (ECG), then taken blood for measuring the activities of serum SOD, LDH and CK, and taken hearts for measuring heart weight index (HWI), left ventricular mass index (LHWI), the contents of myocardial hydroxyproline (Hyp)and MDA, and observing the morphological changes of myocardial tissue by HE staining. RESULTS: Compared with rats in normal group, rats in model group showed endurance value decrease, ECG abnormalities (arrhythmia and myocardial ischemia in waveform), increased HWI, LHWI (P<0.01), myocardial Hyp content, myocardial MDA level, and the level of serum LDH and CK, and reduced the serum SOD activity (P<0.05 or P<0.01). Compared with model group, CM could significantly increase endurance value, improve abnormal phenomenon of ECG, lower the HWI, LHWI, myocardial Hyp content, myocardial MDA level, and serum LDH and CK levels were lower, and serum SOD activity increased, especially in high dose group of CM (P<0.01). HE staining showed in the model group rat ventricular remodeling, myocardial rupture, a large number of collagen fibers, in the treatment group, ventricular remodeling and myocardial fibrosis were significantly improved. CONCLUSION: Cinepazide maleate has protective effect on myocardial injury of rats induced by Iso.