Abstract: AIM: To study protective effects as myocardial ischemic preconditioning of sasanquasaponin (SQS) and its relationship with KATP channel. METHODS: The study adopted the model of myocardial ischemic injury induced by subcutaneous injection of isoproterenol (ISO) in rats, administering specific KATP 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 KATP channel.

Key words: pharmacology, sasanquanonion, K_ATP channel, myocardial ischemic preconditioning, cardioprotection