The Erythropoietin Research On The Relevance Between The Protective Effect And Mechanism Of The Sepsis Rats Myocardial Damage

Objective: To discuss the erythropoietin（EPO）protective effect andmechanism on the sepsis rats myocardial damage．Methods: One hundred and forty-six Kunming healthy mice weredivided into four groups at random and double-blind：the Sham operationgroup（the Sham group n=35，no treatment after the abdominal operation），the Rocephin group（the Roc group n=35，after the model replication injectedimmediately the rocephin1mg/20g），the EPO intervention group（the EPOgroup n=35，after the model replication injected immediately the EPO1000IU/Kg）and the sepsis group（the CLP group n=35，processed the cecumligation and puncture），then observed the seven days death rate of theKunming mice which had been processed the cecum ligation andperforation．Two hundred and fifty-two healthy SD rats were divided intothree groups at random and double-blind：the Sham operation group（the Shamgroup n=8，no treatment after the abdominal operation），the EPO interventiongroup（the EPO group n=8，processed the EPO1000IU/Kg intraperitonealinjection on the base of sepsis model），the sepsis group（the CLP group n=8,processed the cecum ligation and puncture drainage）．Started timing after thececum ligation and puncture， inserted the vessel which connecting thepressure transducer in the right carotid artery at the zero hour，at the thirdhour，the sixth hour，the twelfth hour，the twenty-fourth hour after theoperation，recorded the pressure changes curve of the left ventricular，calculated the left ventricular systolic pressure （LVSP)， the maximumincreasing speed of the left ventricular pressure（+dp/dtmax），the maximumdeclining speed of the left ventricular pressure（-dp/dtmax）．After theoperation dread blood from the inferior vena cava at the zero hour，the third hour，the sixth hour，the twelfth hour，the twenty-fourth hour，applied theEnzyme-Linked ImmunoSorbent Assay test the level of serum C-reactiveprotein（CRP），tumor necrosis factor-a（TNF-a），interleukin-6（IL-6），interleukin-10（IL-10），cardiac troponin I（cTNI），creatine kinase（CK），aspartate aminotransferase （AST） and lactate dehydrogenase（LDH）．Simultaneously using the flow cytometry，the rhodamine123labelto test the cardiomyocyte mitochondrial membrane potential；Using theAnnexin-V-FITC to test the expression level of the cardiomyocyte apoptosisand the myocardial tissue nuclear factor-KB（NF-ΚB p65），observed themorphological changes of the rats’ hearts，livers，kidneys，lungs by lightmicroscope．Data processing by SPSS13.0statistical software package，each indexwas indicated by average value±standard deviation（x±s），the statisticalsoftware made the independent samples bilateral t test to difference groups，p<0.05indicated the difference is significant，p <0.01indicated the differenceis highly significant．Results：All the sepsis groups’ rats had the arrhythmia，acceleratedbreathing，temperature rising，mental deterioration，lethargy，pilo-erection，and other endotoxemia states．Observed the death rate of the Kunming miceafter the cecum ligation and puncture，the Sham group return to normalsituation in three hours after the operation，compared with the CLP group，thedeath rate of the Roc group and the EPO group obviously reduced at thetwenty-fourth hour and the forty-eighth hour，the difference had the statisticalsignificance（p <0.01）.The LVSP and the left ventricle’s+dp/dtmax、-dp/dtmax of the sepsis SD rats were lower than the Sham group，thedifference had the statistical significance（p<0.01），it indicated that the sepsishad the clear effect on left ventricle’s systolic and diastolic function．The ratsof the CLP group appeared the LVSP at the third hour，the index of+dp/dtmax and the-dp/dt max reduced．It reached the lowest（67.4±6.1）mmHg atthe sixth hour，（2821±372.6）mmHg/s，（-1351±151.3）mmHg/s，all lowerthan the Sham group （189.5±3.6） mmHg，（6021±103.6） mmHg/s， （-5245±176.3）mmHg/s，the difference had the statistical significance（p<0.01）．Compare with the CLP group，the LVSP，the+dp/dtmax and the-dp/dtmax of the EPO group were all recovered，which were higher than theCLP group at the third hour，the sixth hour，the twelfth hour and thetwenty-fourth hour， the difference had the statistical significance（p<0.01）．Compare with the Sham group，the CLP group and the EPOgroups’ level of the serum inflammatory mediators index CRP、TNF-a、IL-6、IL-10， myocardial enzymology index cTNI、 CK、 AST、 LDH weresignificantly rose at each time point（p<0.05），after applying the EPO，theabove-mentioned index of the EPO group had different degrees reduced to theCLP group，the difference had the statistical significance（p<0.05）．The CLPgroup and the EPO group，whose cardiac cell early apoptosis rate（8.54±1.33）%，（1.81±0.79）%were all increased than the Sham group（0.27±0.31）%，the difference had statistical significance （p<0.01）．Thecell early apoptosis rate of the EPO group was lower than the CLP group，thedifference had statistical significance（p<0.01）．The myocardial mitochondrialmembrane potential of the Sham group，the EPO group and the CLP groupwere respectively（340.42±25.90），（286.25±24.02）and（192.26±23.69），the cardiac myocyte fluorescence peak of the CLP group and the EPO groupobvious left shift, that is,the cells which mitochondrial membrane potentialreduced were obviously increased, the difference had statistical significance（p<0.01）．After the EPO intervention，the cardiac myocyte fluorescencepeak of the CLP group and the EPO group obvious right shift，that is madeobvious improvement to the mitochondrial membrane potential reduction．Themyocardial tissue NF-ΚB p65expression of the EPO group and the CLPgroup（276.23±28.04）、（442.04±62.26）, were both higher than the Shamgroup（171.59±16.71），and the NF-ΚB p65expression of the EPO group waslower than the CLP group， the difference had statistical significance（p<0.01）．After applying the EPO intervention，compared with the sepsisgroup， the pathological changes of the major organ damage obviouslydecreased． Conclusions：The EPO could reduce the septic rats myocardial damage，which had the protective action；the EPO could inhibit inflammatory cytokineTNF-a，IL-6，enhanced the level of the Anti-Inflammatory cytokine，alleviatedthe myocardial inflammatory reaction；the EPO could improve the reductionof the mitochondrial membrane potential，with an action of resisting the septicrats cardiac myocyte apoptosis， it was related to reduce NF-ΚB p65expression．...