Objective: To study the effect of ginsenoside Rb1 on isoproterenol(ISO) induced myocardial ischemia in rats. Method: The 75 SPF SD rats were randomly divided into normal group

model group

puerarin group

Rb1 low dose group

and Rb1 high dose group

n=15 in each group. The rats in normal group and model group received the same amount of saline and the treatment groups received intraperitoneal injection(0.01 mL·g-1 weight). With continuous administration for 5 d

0.01 mL·g-1. On day 4 and day 5 after the treatment

all other groups except the normal group received two consecutive subcutaneous multi-point injections of ISO 30 mg·kg-1

and the normal group received the same amount of normal saline

at volume of 0.01 mL·mg-1 weight. The effect of ginsenoside Rb1 on rat ECG was observed

laser speckle was used to detect cardiac surface microcirculation

and ELISA was used to detect serum lactate dehydrogenase(LDH)

creatine kinase(CK)

glutathione synthetase(GSH)

nitric oxide(NO)

superoxide dismutase(SOD) and malondialdehyde(MDA) content. Result: Compared with the normal group

the heart rate of rats in model group was significantly increased. Electrocardiogram ST segment showed significant decrease. The blood microcirculation of heart surface was significantly decreased. The serum LDH

CK activity and MDA level were significantly increased

and serum SOD activity and GSH

NO levels were significantly decreased(P<0.01

P<0.05). Compared with the model group

Ginsenoside Rb1(10

20 mg·kg-1) could effectively reduce the heart rate

with increase of electrocardiogram ST segment

significantly increase the blood microcirculation of heart surface

significantly decrease serum LDH

CK activity and MDA level

increase serum SOD activity and GSH

NO levels(P<0.01

P<0.05)

and reduce the degree of myocardial injury. Conclusion: Ginsenoside Rb1 has a protective effect on ISO-induced acute myocardial ischemia

which may be related to inhibiting lipid peroxidation and damages repairing.