Protective effects of Nicotine pretreatment against myocardial ischemia and reperfusion injury in rats

ObjectiveTo investigate the protective effect of nicotine against myocardial ischemia and reperfusion injury in rat.MethodsThirty male Sprague-Dawley rats weighting 200-250 g were randomly divided into three groups:ischemia and reperfusion injury group (group I-R),nicotine 400 g/kg group(group N),sham-operation(group Sham). In sham group the anterior descending branch of left coronary artery was exposed but not occluded,in group I-R the anterior descending branch of left coronary artery was occluded for 30 min followed by 90 nim reperfusion,in group N nicotion 400 g/kg was injection i.v.30 min before myocardial ischemia. At the end of 90 min reperfusion the animals were killed and the hearts were harvested for histopathology change and MPO activity. MDA contents and SOD and CK-MB activity were detected.ResultsMyocardial ultrastructure was well preserved in group N as compared to group I-R. MDA contents and CK-MB and MPO activity were significantly increased in group I-R and nicotion 400 g/kg pretreatment significantly reduced that by I-R. SOD activity was significantly higher in group N than in group I-R.ConclusionNiction has cardioprotective effect on myocardium against I-R in rats.Decrease in oxygen free radicals and increased antioxidant activity may be involved in the mechanism.