Objective: To investigate the effects of total glucosides from Paeoniae Radix Alba (TGP) on endoplasmic reticulum stress and apoptosis in myocardial ischemia reperfusion rats. Method: Female Sprague-Dawley rats were used to establish myocardial ischemia reperfusion models and randomly divided into sham operation group

ischemia reperfusion (I/R) group

TGP low-dose group (ig 50 mg · kg-1 · d-1)

TGP middle-dose group (ig 100 mg · kg-1 · d-1)

and TGP high-dose group (ig 200 mg · kg-1 · d-1). Changes of cardiac function were observed in various groups; myocardial infarction size was detected by triphenyltetrazolium chloride (TTC) staining; levels of myocardial glucose regulating protein78(GRP78)

CCAAT/EBP homologous protein (CHOP)

Caspase-12 and Caspase-3 protien expression were measureed by Western blot; the apoptotic cardiomyocytes were assessed by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL). Result: As compared with the sham operation group

T-wave elevation and LVEDP were significantly increased; LVSP and +dp/dtmax were significantly reduced; and the protein expression levels of GRP78

CHOP

Caspase-12

and Caspase-3 were significantly increased in I/R group (P<0.01)

with obvious myocardial infarction size and cells apoptosis. As compared with I/R group

T-wave elevation and LVEDP were reduced; LVSP and +dp/dtmax were increased; and the protein expression levels of GRP78

CHOP

Caspase-12 and Caspase-3 were reduced (P<0.05

P<0.01) in TGP groups in a concentration-dependent manner

with reduced myocardial infarction size and cells apoptosis. Conclusion: TGP can improve the cardiac function

myocardial infarction and apoptosis in myocardial ischemia reperfusion rats

and its mechanism may be associated with inhibiting the expression levels of GRP78

CHOP

Caspase-12 and Caspase-3.