Objective: To investigate the protective mechanism of quercetin(Que) on myocardial ischemia reperfusion injury(MIRI) in rats. Method: The rats were randomly divided control group

MIRI model group

positive control group (diltiazem HCl 0.01 mg·kg-1) and low

medium and high dose Que pretreatment group (15

30

60 mg·kg-1)

10 rats each group. The myocardial ischemia reperfusion model was induced by occulusion of the anterior descending coronary artery for 30 min and reperfusion for 60 min. Each Que dose was proconditioned for a week

and the rats serum and cardiac muscle tissue werecollected seperately 60 minutes after MIRI. The contents of malondialdehyde (MDA)

interleukin 6 (IL-6)

tumor necrosis factor-α(TNF-α)

creative kinase MB(CK-MB) and troponin(cTnI); the acitivity of superoxygen dehydrogenises(SOD)

glutathione peroxidase(GSH-Px) and Sarcoplasmic reticulum Ca2+ pump (SERCA). And by tetrazolium chloride (TTC) staining

the areas of myocardial damage and infraction were observed. Result: In the MIRI group

the contents of MDA (17.71±3.24)μmol·L-1

CK-MB (2 010.21±76.31) U·L-1

cTnI (2.25±0.76) μg·L-1

IL-6 (5.89±0.34) ng·L-1 and TNF-α (114.12±22.13) μg·L-1 in serum were obviously improved(P<0.01 or P<0.05)

and acitivity of SOD (77.58±5.20) U·mL-1

GSH-Px (11.22±4.88) U·mL-1

and myocardial SERCA (2.76±0.49) μmol·mg-1·h-1 were obviously reduced (P<0.01 or P<0.05). The contents of MDA

CK-MB

cTnI

IL-6 and TNF-α in serum in MIRI group were obviously reduced by medium and high dose Que pretreatment (P<0.01 or P<0.05)

and acitivity of SOD

GSH-Px and myocardial SERCA were improved by medium and high dose Que pretreatment (P<0.01 or P<0.05)

and the areas of myocardial damage and infraction were obviously reduced (P<0.01 or P<0.05). Conclusion: Que preconditioning can alleviate the oxidative stress injury

reduce the inflammatory response and calcium overload in cells

and can indicate obvious protective mechanism on myocardial ischemia/reperfusion injury of rats.