Objective: To explore the effects of lycopene on ischemia reperfusion injure in heart of isolated guinea pig. Method: Thirty isolated guinea pig hearts were divided into five groups:control group

model group

lycopene L group(2.5 mg·L-1)

lycopene M group(5 mg·L-1)

lycopene H group(10 mg·L-1). Heart rate(HR)

coronary flow(CF)

infarct size

lactate dehydrogenas (LDH) in effluent

malondiadehyde (MDA) and superoxide dismutase (SOD) in heart tissues were measured in different groups. Result: The indexes of each group are changed after reperfusion

when reperfusion 60 min

compared with the control group

model group showed that HR was decresed (125±9)

(169±16)stroke per·minute-1

P<0.01

CF decreased(3.48±0.43)

(5.53±0.30)mL·min-1

P<0.01; infarct size increased (19.57±2.34)%

(1.57±0.29)%

P<0.01. the level of LDH increased(206.67±11.85)

(120.96±13.56)U·L-1

P<0.01

SOD activity decreased(99.14±8.24)

(153.22±8.93)U·mg-1

P<0.01; the level of MDA increased(6.17±0.73)

(3.80±0.41)μmol·g-1

P<0.01.Compared to model group

Lycopene group reduced infarct size and releases of LDH in effluent and MDA in heart tissues

increased HR

CF and the activity of SOD in heart tissues. Conclusion: The findings indicate that in the isolated guinea pig heart

lycopene can protect myocardium against ischemia/reperfusion injury and the mechanism could be related to lipid peroxidation in heart.