[Protective effect of polysaccharide pretreatment on myocardial ischemia reperfusion injury in rats]

To study the protective effects of polysaccharides on myocardial ischemia reperfusion injury in rats after preconditioning.

The myocardial ischemia reperfusion model was established by reversible left anterior descending coronary artery ligation: 0. 5 h was myocardial ischemia and 2 h was re perfused. A total of 50 healthy SD rats were randomly divided into 5 groups: sham operation group, model group, polysaccharide high dose group, polysaccharide middle dose group and polysaccharide low dose group, 10 rats in each group. The polysaccharide group was given 100, 50, 10 mg/kg of camphora polysaccharides at 30 min before operation, while the model group and the sham operation group were treated with equal dose of saline. The expression of malondialdehyde( MDA), catalase( CAT), superoxide dismutase( SOD), creatine kinase( CK) and creatine kinase isoenzyme( CK-MB) in serum of rats and tumor necrosis factor alpha( TNF-α), interleukin-1β( IL-1β) 、interleukin-6( IL-6) in myocardial tissue were detected by Elisa method. The expression of Bcl-2, Bax and Caspase-3 in myocardium was detected by Western-Blot. The infarct size and myocardial tissue HE staining were measured.

Compared with the model group, the infarct size of the rats pretreated with polysaccharides decreased significantly, The levels of MDA, CK, CK-MB in serum and TNF-α, IL-1, IL-6 in myocardium were significantly decreased. The expression of SOD and CAT in serum increased significantly. The expression of Bax and caspase-3 was decreased and the expression of Bcl-2 was elevated in myocardium. HE staining showed that the injury degree of myocardial tissue in pretreated rats treated with polysaccharide was significantly lower than that in model group.

Polysaccharide can reduce the apoptosis of myocardial cells by resisting oxidative stress and inflammatory damage, play a protective role in rats of Myocardial ischemia reperfusion injury.