Protective Effects Of Metabolism Of Endogenous Small Molecules Against Myocardial Ischemia/reperfusion Injury

Part 1: Protective effects of fumaric acid analogs on myocardial hypoxia reoxygenation injuryObjective To study fumaric acid analogs preconditioning myocardial protective effect on myocardial hypoxia reoxygenation injuryMethod Neonatal rat cardiomyocytes in primary culture,with different fumaric acid analogs in the establishment of myocardial ischemia and reperfusion myocardial cell pretreatment,establish neonatal rat cardiomyocytes against hypoxia-reoxygenation injury model,model cell total LDH leakage detection established and compared.Result Compared Normal group,myocardial cells only a very small amount of LDH leakage;hypoxia reoxygenation,myocardial cells within a large number of LDH leakage;compared with the normal group,the difference was significant.Three kinds of endogenous small molecule metabolites in the 25-200 mg / L,a concentration dependent decrease in LDH leakage,which at higher doses,effects are very significant,including the role of the most prominent is L-malic acid in 200 mg / comparison were statistically significant and D-malic acid,oxaloacetic when L dose.Conclusion Fumaric acid analogs Hypoxia myocardial injury has a protective effect,the effect is closely related to the concentration of the drug,wherein the protective effect of L-malic acid is most significant.Part 2: Protective effects of L-malic acid on Myocardial Ischemia Reperfusion InjuryObjective L-malic acid pretreated rats with myocardial ischemia reperfusion injury model in the experimental study of different doses of L-malic acid pretreatment body hemodynamics changes and myocardial infarction area,further study L-malic acid in different doses on myocardial ischemia reperfusion injury.Method L-malic acid pretreated rats with myocardial ischemia reperfusion injury model in vivo study of different doses of L-malic acid pretreatment hemodynamics changes recorded within the left ventricular pressure(LVSP),maximal rate of left ventricular pressure(± dp / dt-max)and left ventricular end-diastolic pressure(LVEDP),myocardial ischemia and reperfusion 180 min,separating the serum.Determination of the indicators: Lactate dehydrogenase(LDH),troponin I(CTN-I),superoxide dismutase(SOD)and glutathione peroxidase(GPX)and myocardial infarct size,further study the protective effect L-malic acid in different doses on myocardial ischemia reperfusion injury.Result L-malic acid pretreated rats,left ventricular end-systolic pressure(LVSP)and maximal rate of left ventricular pressure(± dp / dt-max)significantly increased left ventricular end-diastolic pressure(LVEDP)significantly reduced,rat troponin I(CTnI)and lactate dehydrogenase(LDH)were significantly decreased serum superoxide dismutase(SOD)and glutathione peroxidase(GSH-PX)activity was significantly liter high,significantly reduced myocardial ischemia-reperfusion injury in rats with myocardial ischemia and infarction,reducing infarct size;L-malic acid 180 mg / kg reduced to between 240 mg / kg of myocardial ischemia and infarction,the most significant effect.Conclusion L-malic acid pretreated rats compared to the control group,after myocardial ischemia and reperfusion injury on myocardial significant protective effect,and was positively correlated with the dose of the drug,180mg/kg--240mg/kg concentration L-malic acid on myocardial protection works best.Part 3: The mechanism of L-malic acid on myocardial ischemiareperfusion injury.Objective To further examine the mechanism of L-malic acid on myocardial ischemiareperfusion injury.Method Choose the second part 240 mg / kg concentrations of L-malic acid pretreated rats until after myocardial ischemia-reperfusion injury in rats were sacrificed 3h,remove the cardiac muscle of rats.Western Blot method to detect myocardial tissue content and total Nrf2 nuclear translocation of Nrf2 expression and downstream of NQO1,Keap1,HO-1 expression.Result Compared with the control group,DMF and LM cells total protein and nuclear Nrf2 protein levels were significantly increased,the result has a very significant difference,suggesting that LM can promote the expression and promotion of their nuclear translocation of Nrf2 myocardial cells;and Nrf2 expression and nuclear transfer upregulated expression of multiple increase of antioxidant enzymes,such as HO-1,NQO1.After reperfusion,LM preconditioning group in myocardial tissue of HO-1,NQO1 protein levels were significantly increased,the results have a very significant difference;and Keap1 as specific inhibition of Nrf2 protein,the LM model of myocardial preconditioning,the expression down,the result has a very significant difference.Conclusion LM promote myocardial tissue expression and nuclear translocation of Nrf2,thereby enhancing HO-1,NQO1 gene transcription and expression,and thus against ischemia-reperfusion injury.Keap1 inhibit at least one of the mechanisms of its effects by inhibiting Keap1 reduce Nrf2 ubiquitination and degradation,thus contributing to the expression of Nrf2 protein and downstream enhancement,reduction of myocardial ischemia-reperfusion injury.