| Objective: At present,the myocardial ischemia reperfusion(IR)injury has become an important factor affecting the prognosis of acute myocardial ischemic disease such as acute myocardial infarction(AMI),it has attracted more and more doctors’ and researchers’ attention worldwide.Myocardial ischemic postconditioning(IP),first reported by Zhao et al,can reduce the myocardial infarction area,reduce the damage of endothelial function,anti-reperfusion arrhythmia,improve myocardial metabolism and the systolic and diastolic function,reduce myocardial stunning,reduce myocardial ultrastructural damage,inhibit myocardial apoptosis,which has been confirmed in lots of research,and this method of myocardial protection has been widely used in clinic.In this study,the metabolic profile and disease differentiation model of IP and IR was established by using the experimental platform of metabonomics.We explored the metabolites and metabolism pathways highly related to the protective effect of IP.It is expected to provide new targets for the follow-up treatment of disease,to improve the prognosis of patients,and to provide new ideas and directions for the researchers.Methods: Sixty Sprague-Dawlay male rats,10-12 week-old(weight 300±25g),were randomly divided into 10 groups,6 in each group,which were 2 hours,48 hours and 2 weeks after IP group,2 hours,48 hours and 2 weeks after IR group,2 hours,48 hours and 2 weeks after AMI group and the blank control group.The rats were operated on by thoracotomy,and then the balloon and anterior descending branch of left coronary artery were ligated together,which was used to control the opening and occlusion of the left anterior descending branch of the left coronary artery in order to control the ischemia and reperfusion of the myocardium.Among these groups,the IP group underwent ischemic postconditioning according to the principle of 10s/10s*6 after 30 minutes of ischemia.The IR group was directly opened coronary artery to reperfuse after 30 minutes of ischemia.The AMI group wore ligation at the same position of the heart.The changes of electrocardiogram were detected during the operation of all the experimental animals.When the rates were sacrificed,cardiac output and heart rate were measured.Blood samples were taken for metabonomics research.The characteristic metabolites were identified and the weights of related metabolism pathways were analyzed.The plasma samples of experimental animals were analyzed by Accela ultra high performance liquid chromatography with mass spectrometry in order to find the characteristic metabolites.The Mzmine 2.0 data analysis system was used to integrate and analyze the data,and the differential metabolites were screened.The data is introduced into the SIMCA-P+12.0.1.0 system for model recognition,and the PCA model and the OLPS-DA model were constructed.The non-parametric test method is used for statistical analysis,and SPSS statistical software is used to analyze the data.The characteristic metabolites were identified by using HMDB database,the related metabolic pathways were screened,the weight of metabolic pathways were analyzed by using Metaboanalyst 3.0 database,and determined the role of the corresponding characteristic metabolites in the related metabolic pathways,to further determine and search for the characteristic metabolites associated with the myocardial protective effect of IP.Results: We had successfully constructed the rat IP model and IR model in this study,which was based on a large number of literature and related animal experiment study method.In the process of animal model construction,we had used electrocardiogram to monitor the electrocardiogram activity of animals.Obvious ST segment elevation appeared during the ischemic process,which was a typical manifestation of myocardial ischemia and even myocardial infarction.With the opening of coronary artery,the ST segment returned to its original height,which is suggesting the recovery of coronary blood flow.The plasma samples of experimental animals were analyzed by metabonomics,and the plasma metabolic profile of rats was successfully constructed.The preliminary metabolomic data were analyzed and integrated,and the characteristic metabolites related to the myocardial protective effects of IP in different periods were further identified.4 metabolites were selected at 2 days after the operation,namely LysoPC(16:0),(3b,9R)-5-Megastigmene-3,9-diol 9-[apiosyl-(1->6)-glucoside],Pregnanetriol,m/z=340.334.9 at 2 weeks after operation,namely LysoPC(16:0),LysoPC(18:2(9Z,12Z)),LysoPC(P-16:0),Behenic acid,Pregnanetriol,DHAP(18:0e),(3b,9R)-5-Megastigmene-3,9-diol 9-[apiosyl-(1->6)-glucoside],and two other unidentified metabolites were screened,their m/z value were 340.334 and 508.363.There were no characteristic metabolites screened at 2 hours after operation.The metabolic pathway of these metabolites was screened and the above metabolites were mainly involved in the glycerolphospholipid metabolism and biosynthesis of unsaturated fatty acid.Conclusion: Myocardial ischemic postconditioning is a means of myocardial protection by multiple blocking and reperfusion in the early stage of reconstructing the blood supply of the myocardium.In this study,we used animal experiments to simulate two cases of myocardial ischemic postconditioning and myocardial ischemia reperfusion.Based on the metabonomics platform,we screened the metabolites which were highly correlated with myocardial protective effects of myocardial ischemic postconditioning at different time periods,and screened related metabolic pathways.From the perspective of metabonomics,we elaborated the mechanism of myocardial protective effect of myocardial ischemic postconditioning,and provided new therapeutic targets and research directions for clinicians and researchers. |
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