| Objective:To investigate the protective effect of polygonatum extract on mitochondrial damage and apoptosis in myocardial cells of myocardial ischemia-reperfusion injury in rats.Methods:Fifty male Wistar rats were randomly divided into sham operation group,model group,polygonatum extract low,medium and high dose groups.Myocardial ischemia-reperfusion model was established by reversible left anterior descending to ligation,and myocardial ischemia was given to rats for 30 min and reperfusion for 120 min.30min before ligation Polygonatum extract low,medium and high dose group rats were given O.lg,0.2g,0.3g/kg ip polygonatum extract,model group and sham operation group given the same volume of saline ip;Hemodynamic parameters of rats was record;The apoptosis of ventricular myocytes in each group was observed by TUNEL staining.The morphology and pathological changes of myocardial mitochondria were observed by transmission electron microscopy.The levels of free fatty acid(FFA),adenosine monophosphate(ATP),adenosine monophosphate(AMP),lactate(LAC)in myocardium of rats were detected by enzyme-linked immunosorbent assay(ELISA).The protein expressions of Caspase-3,9,12 in ventricular myocytes were detected by Western blot.Myocardial mitochondria were isolated for determination of superoxide dismutase(SOD)activity and malondialdehyde(MDA)and free calcium content.Result:(1)Compared with the sham operation group,the left ventricular systolic pressure(LVSP)and the maximal rising rate of left ventricular pressure(+ dp/dtmax)were decreased in the model group;Left ventricular end diastolic pressure(LVDP),the maximum descending rate of left ventricular pressure(-dp/dtmax)were increased.Myocardial apoptosis was obvious.The content of FFA and LAC in myocardium was increased,the expression of Caspase-3,9 and 12 was increased,the ratio of ATP/AMP was decreased,the mitochondrial membrane was disintegrated,the inner crest was disappeared,the content of mitochondrial SOD and free calcium were decreased,and MDA content was increased(P<0.05);(2)Compared with the model group,the levels of FFA and LAC in myocardial tissue of rats treated with low,medium and high doses of polygonatum extract was improved,the levels of Caspase-3 9,12,and the ratio of ATP/AMP was increased.The content of SOD and free calcium in mitochondria was increased and the content of MDA was decreased(P<0.05).Conclusion Polygonatum extract can improve myocardial ischemia-reperfusion injury and reduce myocardial apoptosis,the mechanism may be related to the protection of mitochondria and enhance myocardial cell mitochondrial energy metabolism. |
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