Study on the protective effect of paeoniflorin against myocardial infarction in rats by the cAMP-PKA singal pathway

Wang Jianfa; Zhao Guoan

doi:10.3969/j.issn.1674-4055.2018.04.26

Abstract：Objective To investigate the protective effect of paeoniflorin against myocardial infarction(MI) in rats and explore preliminaryly the related molecular mechanism involved. Methods 50 rats were selected to establish MI model by ligating coronary artery and randomly divided into the model group (constant volume normal saline), positive control group (10 mg/kg vassartan), high paeoniflorin dose group (100 mg/kg,), medium paeoniflorin dose group (50 mg/kg) and low paeoniflorin dose group (25 mg/kg), with 10 rats in each group. Another 10 rats were selected as sham-operation group (constant volume normal saline), which experienced the same procedure with MI model without ligation. All the rats were given continuously for 4 weeks. The changes of S-T segment, serogical examination, myocardial histopathology and myocardial infarct size were observed, and the expression levels of cAMP, PKA in myocardial tissue were determined. Results The S-T segment in electrocardiogram of operated rats was significantly elevated, suggesting that the model of MI was successful, which could be used for subsequent experiments. Four weeks after the treatment, the treatment group rats serum CK, LDH activity were significantly lower (P<0.05). SOD activity was significantly increased (P<0.05), and paeoniflorin high dose group was close to control group in serogical examination. The treatment group can significantly improve the myocardial nucleus fixation, fragmentation, necrosis and so on. The area of myocardial infarction of rats in each treatment group significantly decreased (P<0.05). The expression levels of cAMP and pPKA, pCREB in the myocardial tissue of treated rats were significantly increased (P<0.05). Conclusion Paeoniflorin may play a protective role in myocardial infarction by the cAMP-PKA signal pathway and the therapeutic effect is dose-dependent, which can provide a theoretical reference for the clinical treatment of myocardial infarction.