Object To study the protective effect and pharmacological ischemic preconditioning of sasanquasaponin (SQS) on intact rat heart and its relationship with NO Methods A model of rat myocardial ischemia induced by sc injection of isoproterenol (ISO) was prepared, and after the administration of selective NO synthesis inhibitor methylene blue (MET), the ECG, serum creatine kinase (CK) activity, free fatty acid (FFA) and adenosine contents were determined Results Preconditioning iv injection of SQS can effectively protect the myocardium from ischemia induced by ISO The cardio protective effect was significantly attenuated when the NO synthesis inhibitor MET were injected prior to SQS Conclusion SQS can effectively protect myocardium ischemia induced by ISO and the protection is most likely to be mediated by NO

AIM: To study protective effects as myocardial ischemic preconditioning of sasanquasaponin (SQS) and its relationship with K ATP channel. METHODS: The study adopted the model of myocardial ischemic injury induced by subcutaneous injection of isoproterenol (ISO) in rats, administering specific K ATP channel blocker gliberclamide (GLI 5 mg?kg -1 ). Four groups were set as NS group, I/R group, SQS group ( 0.2 mg?kg -1 ), and GLI group (5 mg?kg -1 ). Prior to injection of ISO, all agents were intraveneously injected into rats for 3 days, one time per day. Subsequently, ISO was subcutaneuously injected into rats by the ways of many different sites, and some indices were measured including ECG, serum creatine kinase (CK) activity, free fatty acid (FFA), and adenosine contents in rats. RESULTS: Preconditioningly intravenous injection of SQS could effectively protect myocardium from ischemic injury induced by ISO. With GLI injected prior to SQS, the cardioprotective effects of SQS were significantly attenuated. CONCLUSION: SQS can protect myocardium from ischemic injury induced by ISO, and the protection may be mediated by K ATP channel.

AIM In this study, we observe the effects of SQS on contents of myocardial malondialdehyde(MDA)and activities of superoxide dismutase(SOD) and glutathione peroxidase(GSH Px) through adopting the model of myocardial ischemic injury induced by subcutaneous injection of isoprenaline(ISO 4 mg?kg -1 ?d -1 ?2 d) into rats. METHODS Four groups were divided, namely NS, I/R, SQS1 and SQS2 group. The contents of MDA and activities of SOD and GSH Px were examined after administering SQS for 3 days(1 time per day). RESULTS The results show the elevation of S T in ECG, increase of MDA contents and decrease of SOD and GSH Px activities in I/R group. SQS may antagonize the changes of MDA, SOD and GSH Px induced by ISO, revealing the relationship to dose dependence. CONCLUSION SQS is most likely to possess the capabilities of anti oxygen free radicals and anti lipoperoxidation to myocardial ischemic injury induced by ISO.