六味通心颗粒对大鼠心肌缺血再灌损伤模型心功能的影响

目的观察六味通心颗粒对大鼠心肌缺血再灌损伤模型左室收缩压（LVSP）、左室舒张末压（LVEDP）、左心室的最大收缩速率（＋dp／dtmax）、左心室最大舒张速率（-dp／dtmax）的影响，探讨六味通心颗粒对大鼠心肌缺血再灌损伤模型的作用。方法雄性SD大鼠36只，体重180—220g，按体重随机分为三组，假手术组、缺血再灌注组、预防给药组；预防给药组连续给药4周后实验，连续观察2h各组大鼠心电图及心功能LVSP、LVEDP、＋dp／dtmax、-dp／dtmax的水平，腹主动脉取血离心去血清-80℃储存备用，取300mg心脏组织匀浆离心取上清-80℃储存，取部分心脏组织放于中性甲醛溶液固定。结果与模型组比较，预处理组在缺血期、再灌注期能升高LVSP、＋dp／dtmax水平一dp／dtmax，对LVEDP的升高有一定的抑制作用（P〈0．05、P〈0．01）。结论预防给药组对大鼠心肌缺血再灌损伤模型心功能有一定的改善作用。

Protective Effects of Zingiberis and Acniti Praeparatae Decoction on Myocardial IschemiaReperfusion Injury in Rats

This study aimed to investigate the protective effects of zin-giberis and acniti praeparatae decoction on oxidative stress injury induced by my-ocardial ischemia reperfusion in rats. [Method] Myocardial ischemia-reperfusion was performed by ligation of the left anterior descending coronary artery for 30 min, fol-lowed by reperfusion for 60 min. The effects of zingiberis and acniti praeparatae decoction on ECG ST segment, myocardial infarction percentage, malondialdehyde （MDA） content in the serum, superoxide dismutase （SOD） activity and other indica-tors were observed. [Result] Zingiberis and acniti praeparatae decoction could effec-tively inhibit ECG ST segment elevation caused by myocardial ischemia-reperfusion injuries, reduce the percentage of myocardial infarction, decline the content of MDA in the serum, and increase the activity of SOD. [Conclusion] Zingiberis and acniti praeparatae decoction exhibits protective effects on oxidative injuries caused by my-ocardial ischemia-reperfusion injuries in rats, which may be involved in reducing the formation of myocardial free radicals and enhancing antioxidant capacity of my-ocardium.

The role and modulation of autophagy in experimental models of myocardial ischemia-reperfusion injury

A physiological sequence called autophagy qualitatively determines cellular viability by removing protein aggregates and damaged cyto-plasmic constituents, and contributes significantly to the degree of myocardial ischemia-reperfusion （I/R） injury. This tightly orchestrated cata-bolic cellular‘housekeeping’ process provides cells with a new source of energy to adapt to stressful conditions. This process was first described as a pro-survival mechanism, but increasing evidence suggests that it can also lead to the demise of the cell. Autophagy has been implicated in the pathogenesis of multiple cardiac conditions including myocardial I/R injury. However, a debate persists as to whether autophagy acts as a protec-tive mechanism or contributes to the injurious effects of I/R injury in the heart. This controversy may stem from several factors including the va-riability in the experimental models and species, and the methodology used to assess autophagy. This review provides updated knowledge on the modulation and role of autophagy in isolated cardiac cells subjected to I/R, and the growing interest towards manipulating autophagy to increase the survival of cardiac myocytes under conditions of stress-most notably being I/R injury. Perturbation of this evolutionarily conserved intracellular cleansing autophagy mechanism, by targeted modulation through, among others, mammalian target of rapamycin （mTOR） inhibitors, adenosine monophosphate-activated protein kinase （AMPK） modulators, calcium lowering agents, resveratrol, longevinex, sirtuin activators, the proapoptotic gene Bnip3, IP3 and lysosome inhibitors, may confer resistance to heart cells against I/R induced cell death. Thus, therapeutic ma-nipulation of autophagy in the challenged myocardium may benefit post-infarction cardiac healing and remodeling.

Effect of shenfu injection on gastrointestinal microcirculation in rabbits after myocardial ischemia-reperfusion injury

AIM： To investigate the effect of shenfu injection on gastrointestinal microcirculation after myocardial ischemic-reperfusion （IR） injury in rabbits and probe into the mechanism. METHODS： Forty healthy flap-eared white rabbits were randomly divided into 4 groups： IR injury control group （group Ⅰ ）, shenfu injection 5 mL/kg per h group （group Ⅱ）, shenfu injection 10 mL/kg per h group （group Ⅲ） and shenfu injection 20 mL/kg per h group （group Ⅳ）. The four groups were treated with Lactated Ringer＇s solution, shenfu injection 5, 10, and 20 mL/ kg per h were infused intravenously 30 min before experiment respectively. The values of hemodynamics [mean arterial pressure （MAP）, heart rate （HR）, gastric intramucosal partial pressure of carbon dioxide （PCO2）, blood gas analysis and pH] were measured and compared with those before myocardial ischemia, 60 min after myocardial ischemia and 60, 90, and 180 rain after reperfusion. RESULTS： The MAP, HR and gastric intramucosal pH were （70.50 ± 4.50） kPa, （165 ± 14） beats per rain, 7.032 ± 0.024 in group Ⅰ 60 min after myocardial ischemia, which were significantly decreased compared with those before myocardial ischemia （88.50 ± 9.75 kPa, 217 ± 18 beats per rain, 7.112 ± 0.035, P 〈 0.05）. The MAP, HR and gastric intramucosal pH were significantly decreased in group Ⅰ 60, 90, and 180 min after reperfusion （61.50 ± 5.25 kPa, 133 ± 31 beats per rain, 6.997 ± 0.025） compared with those before reperfusion respectively （P 〈 0.05）, whereas the values were insignificantly different in groups Ⅱ, Ⅲ or Ⅳ after reperfusion, compared with those before reperfusion, and there were no significant differences between groups Ⅱ, Ⅲ, and Ⅳ after reperfusion. CONCLUSION： Pre-infusion of shenfu injection has a protective effect on gastrointestinal microcirculation after myocardial IR injury in rabbits, in a dose independent manner.

Effect of Intracoronary Infusion of Bone Marrow Mononuclear Cells or Peripheral Endothelial Progenitor Cells on Myocardial Ischemia-reperfusion Injury in Mini-swine

Objective To simulate and assess the clinical effect of intracoronary infusion of bone marrow mononuclear cells or peripheral endothelial progenitor cells on myocardial reperfusion injury in mini-swine model. Methods Twenty-three mini-swine with myocardial reperfusion injury were used as designed in the study protocol. About （3.54±0.90）×10^7 bone marrow mononuclear cells （MNC group, n=9） or （1.16± 1.07）× 10^7 endothelial progenitor cells （EPC group, n=7） was infused into the affected coronary segment of the swine. The other mini-swine were infused with phosphate buffered saline as control （n=7）. Echocardio- graphy and hemodynamic studies were performed before and 4 weeks after cell infusion. Myocardium infarc- tion size was calculated. Stem cell differentiation was analyzed under a transmission electromicroscope. Results Left ventricular ejection fraction dropped by 0% in EPC group, 2% in MNC group, and 10% in the control group 4 weeks after cell infusion, respectively （P〈0.05）. The systolic parameters increased in MNC and EPC groups but decreased in the control group. However, the diastolic parameters demonstrated no significant change in the three groups （P〉0.05）. EPC decreased total infarction size more than MNC did （1.60±0.26 cm2 vs. 3.71±1.38 cm2, P〈0.05）. Undermature endothelial cells and myocytes were found under transmission electromlcroscope. Conclusions Transplantation of either MNC or EPC may be beneficial to cardiac systolic function, but might not has obvious effect on diastolic function. Intracoronary infusion of EPC might be better than MNC in controlling infarction size. Both MNC and EPC may stimulate angiogenesis, inhibit flbrogenesis, and differentiate into myocardial cells.

The therapeutic effect of Jiawei Danshen Decoction on myocardial ischemia-reperfusion injury by inhibiting H_(2)S-mediated autophagy signaling pathway

Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Chain 3 A/B(LC3 A/B),p62,and autophagy protein5(ATG5).Methods Seventy specific pathogen free(SPF)Sprague-Dawley(SD)rats were randomly assigned to seven groups(n=10 in each group),including normal control,sham operation,MIRI model(model),ischemic preconditioning,Na HS,JWDSD,and JWDSD+CSE inhibitor(JWDSD+PPG)groups,and orally administered the indicated drugs for 14 d.Two hours after the last administration,the left anterior decreased branch of the coronary artery of each rat in model,Na HS,JWDSD,and JWDSD+PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model,and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation.Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay(ELISA).Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 m RNA expression and Western blot analysis of Beclin1,LC3 A/B,and p62 protein expression.Results(1)The serum H2S content in model group rats was significantly reduced(P<0.01),JWDSD significantly increased the serum H2S content of model group rats(P<0.01),and the CSE inhibitor(PPG)significantly reduced H2S levels in the JWDSD group rats(P<0.01).(2)Compared with the normal control group,the myocardial tissue necrosis and cell destruction occurred in the MIRI model group,and JWDSD could alleviate the myocardial tissue necrosis of model rats,but the ameliorative effect of JWDSD could be reversed by PPG.(3)Beclin1,LC3 A/B,and p62 expression levels in the heart tissues of the model group were significantly increased(P<0.001),whereas decreased by JWDSD(P<0.05,P<0.01,and P<0.001,respectively),and the inhibitory effects of JWDSD on Beclin1,LC3 A/B,and p62 expression were partially reversed by PPG(P<0.01,P<0.05,and P<0.01,respectively).(4)The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group(P<0.001).JWDSD clearly downregulated the expression levels of Beclin1 and ATG5(P<0.05 and P<0.001,respectively),which were reversed by PPG(P<0.001).Conclusion Our experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation,and downregulating the expression of Beclin1,LC3 A/B,p62 and ATG5,which are related to inhibiting autophagy signaling.

Mediated protective effect of electroacupuncture pretreatment by miR-214 on myocardial ischemia/reperfusion injury

Background Electroacupuncture pretreatment plays a protective role in myocardial ischemia/reperfusion （I/R） injury and microRNAs （miRNAs） could act on various facets of cardiac function. However, the role of miRNAs in the cardioprotection by electroacupuncture pre-treatment on myocardial I/R injury remains unknown. The purpose of the study was to examine whether miR-214 was involved in cardio-protection by electroacupuncture. Methods Using rat myocardial I/R model, we examined the role of electroacupuncture pretreatment in myocardial I/R injury and analyzed the changes in the expression of miR-214. In addition, I/R was simulated in vitro by performing oxy-gen-glucose deprivation （OGD） on H9c2 cell cultures, and the effect of electroacupuncture pretreatment on I/R injury as well as expressional level of miR-214 were examined in vitro. Furthermore, the miR-214 mimic was transfected into OGD-treated H9c2 cells, we analyzed the cell apoptosis, lactate dehydrogenase （LDH） and creatine kinase （CK） activities, intracellular free Ca2＋concentration （[Ca2＋]i） as well as the relative protein levels of sodium/calcium exchanger 1（NCX1）, BCL2-like 11 （BIM）, calmodulin-dependent protein kinase IIδ（CaMKIIδ） and Cyclophilin D （CypD）. Results The in vivo results revealed that compared with the I/R group, the electroacupuncture pretreatment group showed significant decreased myocardial infarct size, as well as the increased indices of the cardiac function, including heart rate, mean arterial pressure, left ventricular systolic pressure and maximal rate for left ventricular pressure rising and declining （±dp/dt max）. In addition, electroacupuncture pretreatment could inhibit the elevation of LDH and CK activities induced by I/R injury. The quantitative PCR （qPCR） results demonstrated electroacupuncture pretreatment could provide cardioprotection against myocardial I/R injury in rats with miR-214 up-regulation. In the meanwhile, in vitro, electroacupuncture pretreatment protected H9c2 cells from OGD-induced injury. Trans-fection of miR-214 mimic showed protective effects on OGD-induced injury to H9c2 cells by reducing apoptosis, decreasing LDH and CK activities, rescuing the OGD-induced Ca2＋and down-regulating elevated protein levels of NCX1, BIM, CaMKIIδand CypD. Conclusions Our findings firstly demonstrated that electroacupuncture pretreatment promotes the expression of miR-214 in myocardial I/R injury and miR-214 contributes to the protective effect of electroacupuncture on myocardial I/R injury.

MicroRNA-15a/b are up-regulated in response to myocardial ischemia/reperfusion injury

Objective Several studies have indicated that miR-15a,miR-15b and miR-16 may be the important regulators of apoptosis.Since attenuate apoptosis could protect myocardium and reduce infarction size,the present study was aimed to find out whether these miRNAs participate in regulating myocardial ischemia reperfusion （I/R） injury.Methods Apoptosis in mice hearts subjected to I/R was detected by TUNEL assay in vivo,while flow cytometry analysis followed by Annexin V/PI double stain in vitro was used to detect apoptosis in cultured cardiomyocytes which were subjected to hypoxia/reoxygenation （H/R）.Taqman real-time quantitative PCR was used to confirm whether miR-15a/15b/16 were involved in the regulation of cardiac I/R and H/R.Results Compared to those of the controls,I/R or H/R induced apoptosis of cardiomyocytes was significantly iucreased both in vivo （24.4％ ± 9.4％ vs.2.2％ ± 1.9％,P ＜ 0.01,n =5） and in vitro （14.12％ ±0.92％ vs.2.22％ ± 0.08％）.The expression of miR-15a and miR-15b,but not miR-16,was increased in the mice I/R model,and the results were consistent in the H/R model.Conclusions Our data indicate miR-15 and miR-15b are up-regulated in response to cardiac I/R injury,therefore,down-regulation of miR- 15a/b may be a promising strategy to reduce myocardial apoptosis induced by cardiac I/R injury.

Progresses in the research of Danhong Injection against the cardial ischemia-referfusion injury

Researches in the field of the myocardial ischemia-reperfusion injury are attracting the attentions of clinicians for the treatments that protect cardiac muscle cells from being injured can not only help the patients get recovery but also keep them in health. By clearing the free radicals and reducing calcium overload of myocardial cell, treatments with Danhong Injection will help myocardial cells survive from inflammatory reactions which are triggered by ischemia reperfusion so as that endothelial function will be improved and myocardial cell apoptosis will be inhibited. In all, Danhong Injection is an ideal medicine for protecting myocardial cell against ischemia reperfusion injury.

Effect of Shenfu injection on nuclear factor-κB during myocardial ischemia/reperfusion injury in rats

Objective: To investigate effects of Shenfu injection on the concentrations of plasma tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), activity of Nuclear Factor kappa B (NF-κB) and heart tissue ultrastructure during myocardial ischemia/reperfusion (I/R) injury in rats and its potential mechanism.Methods: Myocardial ischemia/reperfusion (I/R) was produced by ligation and release of the left anterior descending coronary artery. Ischemia lasted for 30 min and reperfusion for 60 min. Twenty-four healthy male SD rats weighing 230-280 g were randomly divided into three groups (n=8, each): Group I (Sham-operation group); Group II (I/R group); Group III (Shenfu group), in which Shenfu injection (10 ml/kg) was intraperitoneally injected 30 min before ischemia in animals with I/R. The plasma concentrations of IL-6 and TNF-α were measured by ELISA, and the heart was harvested for determination of NF-κB levels by Ecl-western blot analysis. Electron microscopy was used to study its ultrastructure.Results: After reperfusion, NF-κB binding activity in myocardial nuclei and the plasma concentrations of IL-6 and TNF-α were significantly increased in Group II, compared with Group I (P< 0.01), and they were markedly reduced in Group III, compared with Group II (P< 0.01). In addition, electron microscopic examination showed more serious injury of the myocardium ultrastructure in Group II, while in Group III the myocardial ultrastructure was similar to normal state.Conclusions: Shenfu injection inhibits NF-κB activity in I/R myocardium and leads to down-regulation of proinflammatory cytokine expression, which might be one of the molecular mechanisms of Shenfu injection in cardioprotection.

Effects of Acupuncture Pretreatment on Ischemic Cardiac Muscle Cell Apoptosis and Gene Expression in Ischemia-reperfusion Rats

Objective： To investigate the protective effects of acuptmcture pretreatment on ischemic myocardium, the protective mechanism of acupuncture pretreatment on ischemic myocardium was explored by observing the cardiac muscle cell apoptosis and the expression of HSP70 mRNA of ischemia-reperfusion injury rats treated with acupuncture pretreatment. Methods： Sixty-four Wistar rats were randomly divided into eight groups： control group, sham surgery group, ischemia-reperfusion group, ischemia pretreatment group, manual acupuncture pretreatment group （once a day）, electroacupuncture pretreatment group （once a day）, manual acupuncture pretreatment group （twice a day）, and electroacupuncture pretreatment group （twice a day）. The reperfusion model of rat myocardial ischemia was made. Expression of HSP70 mRNA was assayed by in situ hybridization, and cell apoptosis by TUNEL. Results： Compared with those in the control group and the sham surgery group, the apoptosis and the expression of HSP70 mRNA were increased in the ischemia-reperfusion group. Compared with those in the ischemia-reperfusion group, the cardiac muscle cell apoptosis was decreased and the HSP70 mRNA was increased in the rats treated with acupuncture pretreatment; meanwhile, acupuncture pretreatment twice a day had stronger effects than acupuncture pretreatment once a day and ischemia pretreatrnent. Conclusion： Acupuncture pretreatment can inhibit the cardiac muscle cell apoptosis, and up-regulate the expression of HSP70 mRNA in ischemia-reperfusion rats. Acupuncture pretreatment twice a day has stronger effects than pretreatment once a day.

Protective effects of tanshinone ⅡA derivative on myocardial ischemia/reperfusion injury in rats

Tanshinone ⅡA（TSⅡA） is the major bioactive constituent of Salvia miltiorrhiza Bunge,a Chinese herbal medicine,which has protective effects on myocardial ischemia/reperfusion（MIR） injury.However,the cardioprotective effects of TSⅡA as well as its clinical use were limited due to its poor water solubility.The objective of this study was to evaluate whether Tanshinone ⅡA derivative（TD）,a new water soluble compound synthesized by TSⅡA and N-Methyl-D-Glucamine,had protective effects on MIR injury and what the related mechanism was.The cardioprotective effects of TD were evaluated and compared with TSⅡA in a rat MIR model.The results show that pretreatment with TD significantly alleviated inflammatory infiltration and exhibited antioxidant effect in MIR injury by reducing the activity of lactate dehydrogenase（LDH） and malondialdehyde（MDA）,decreasing expression of nuclear factor-κ-gene binding（NF-κB） and upregulating expression of heme oxygenase（HO-1）,but having no effect on the content of total superoxide dismutase（T-SOD） and m RNA expression of superoxide dismutase（SOD-1）.Thus,our study reveals that TD exerted significant protective effects on MIR injury through attenuating oxidative stress and inflammatory responses.

Effect of electroacupuncture pretreatment on adenine nucleotides in myocardial tissues of rats with myocardial ischemia-reperfusion injury detected by high performance liquid chromatography(HPLC)

Objective:To observe the effect of electroacupuncture(EA)pretreatment on adenine nucleotides in the myocardial tissues of the myocardial ischemia-reperfusion injury(MIRI)rats,and to explore the mechanism of EA pretreatment on myocardial prevention and protection in MIRI rats.Methods:Forty SPF male Sprague-Dawley(SD)rats were randomly divided into 5 groups:a blank group,a sham operation group,a model group,an EA at Neiguan(PC 6)group and an EA at Hegu(LI 4)group,with 8 rats in each group.Rats in the blank group only received binding to the rat plate,30 min/time,once a day for 7 d;on the 7th day,rats in the sham operation group were subjected to threading for 40 min at the left anterior descending coronary artery without ligation,and then the rats were allowed to stand for 60 min before collection of the specimens;on the 7th day,rats in the model group were subjected to threading at the left anterior descending coronary artery with ligation,for 40 min before the blood flow was restored,and then the rats were allowed to stand for 60 min before collection of the specimens;on the 7th day of pretreatment with EA at Neiguan(PC 6)or Hegu(LI 4)for 30 min per day(once a day for 7 d),rats in the EA at Neiguan(PC 6)group and EA at Hegu(LI 4)group were subjected to modeling and sample collection same as in the model group.The left ventricular myocardium of the lower left anterior descending coronary artery was collected from rats in all 5 groups.Hematoxylin-eosin(HE)staining and transmission electron microscope(TEM)were used to observe the changes in myocardial pathological morphology.The change in the adenine nucleotide level of myocardial tissue was measured by high performance liquid chromatography(HPLC).Results:The HE staining and ultrastructure showed that the myocardial injury was severer in the model group compared with the sham operation group.Compared with the model group,the myocardial injury in the EA at Neiguan(PC 6)and the EA at Hegu(LI 4)groups was mild or hardly any.The adenine nucleotide levels in the sham operation group and the model group were all decreased compared with the blank group(all P<0.05);compared with the sham operation group,the adenine nucleotide level of the model group was also decreased,but the difference was not statistically significant(P>0.05);compared with the model group,the adenine nucleotide level in the EA at Neiguan(PC 6)group was increased(P<0.05),and the adenine nucleotide level in the EA at Hegu(LI 4)group was significantly increased(P<0.01).The adenine nucleotide level in the EA at Hegu(LI 4)group was higher than that in the EA at Neiguan(PC 6)group,but the difference was not statistically significant(P>0.05).Compared with the EA at Neiguan(PC 6)group,the levels of adenosine triphosphate(ATP),adenosine diphosphate(ADP)and adenosine monophosphate(AMP)in the EA at Hegu(LI 4)group were significantly increased(all P<0.01).Conclusion:Both EA at Neiguan(PC 6)and Hegu(LI 4)can alleviate the pathological damage to myocardium in MIRI rats,and increase the adenine nucleotide level in myocardial tissues,and thus protect MIRI rats.EA at Hegu(LI 4)has a better protective effect than Neiguan(PC 6).

Effect of electroacupuncture pretreatment on the protein expression of c-fos in fastigial nucleus and lateral hypothalamus area in rats with acute myocardial ischemia-reperfusion injury

Objective:To observe the effect of electroacupuncture(EA)pretreatment on the protein expression of c-fos in fastigial nucleus(FN)and lateral hypothalamus area(LHA)in rats with acute myocardial ischemia-reperfusion injury(MIRI),and to explore the role and mechanism of FN and LHA in EA at the Heart Meridian fighting against acute MIRI reaction.Methods:Seventy Sprague-Dawley rats were randomly divided into a sham operation group,a model group,an EA-Heart Meridian group and an EA-Lung Meridian group,with 14 rats in each group;an LHA lesion plus EA-Heart Meridian group(LHA+EA-Heart Meridian group)and a FN lesion plus EA-Heart Meridian group(FN+EA-Heart Meridian group),with 7 rats in each group.Except the sham operation group,the left anterior descending branch of coronary artery was ligated to establish acute MIRI rat models in the other 5 groups.In the three groups with EA-Heart Meridian treatment,Shenmen(HT 7)and Tongli(HT 5)were selected;Taiyuan(LU 9)and Lieque(LU 7)were selected in the EA-Lung Meridian group.All the EA groups received EA stimulation prior to modeling,with 1 mA in current intensity and 2 Hz in frequency,20 min each time,once a day for a total of 7 d.The sham operation group and the model group did not receive EA stimulation.The electrocardiogram was observed in the rats to analyze the ST-segment deviation and cardiac arrhythmia score.The expression of c-fos protein in FN and LHA was detected by immunohistochemistry method.Results:Compared with the sham operation group,the ST-segment deviation,cardiac arrhythmia score and the expression of c-fos protein in the FN and LHA increased significantly in the model group(all P<0.05).Compared with the model group,the ST-segment deviation,cardiac arrhythmia score and the expression of c-fos protein in FN and LHA decreased significantly in the EA-Heart Meridian group(all P<0.05).Compared with the EA-Heart Meridian group,the ST-segment deviation and cardiac arrhythmia score increased significantly in the EA-Lung Meridian group,LHA+EA-Heart Meridian group and FN+EA-Heart Meridian group(all P<0.05);the expression of c-fos in FN increased significantly in the EA-Lung Meridian group and LHA+EA-Heart Meridian group(both P<0.05);the expression of c-fos in LHA increased significantly in the EA-Lung Meridian group and FN+EA-Heart Meridian group(both P<0.05).Conclusion:FN and LHA are involved in the mechanism of EA at Heart Meridian to improve the acute MIRI reactions,and the cerebellum may participate in the improvement of cardiac function by EA through the cerebellum-hypothalamus projection.

Hypertrophic preconditioning attenuates myocardial ischemia/reperfusion injury through the deacetylation of isocitrate dehydrogenase 2

To test the hypothesis that transient nonischemic stimulation of hypertrophy would render the heart resistant to subsequent ischemic stress,short-term transverse aortic constriction(TAC)was performed in mice and then withdrawn for several days by aortic debanding,followed by subsequent myocardial exposure to ischemia/reperfusion(I/R).Following I/R injury,the myocardial infarct size and apoptosis were markedly reduced,and contractile function was significantly improved in the TAC preconditioning group compared with the control group.Mechanistically,hypertrophic preconditioning remarkably alleviated I/R-induced oxidative stress,as evidenced by the increased reduced nicotinamide adenine dinucleotide phosphate(NADPH)/nicotinamide adenine dinucleotide phosphate(NADP)ratio,increase in the reduced glutathione(GSH)/oxidized glutathione(GSSH)ratio,and reduced mitochondrial reactive oxygen species(ROS)production.Moreover,TAC preconditioning inhibited caspase-3 activation and mitigated the mitochondrial impairment by deacetylating isocitrate dehydrogenase 2(IDH2)via a sirtuin 3(SIRT3)-dependent mechanism.In addition,the expression of a genetic deacetylation mimetic IDH2 mutant(IDH2 K413R)in cardiomyocytes,which increased IDH2 enzymatic activity and decreased mitochondrial ROS production,and ameliorated I/R injury,whereas the expression of a genetic acetylation mimetic(IDH2 K413Q)in cardiomyocytes abolished these protective effects of hypertrophic preconditioning.Furthermore,both the activity and expression of the SIRT3 protein were markedly increased in preconditioned mice exposed to I/R.Treatment with an adenovirus encoding SIRT3 partially emulated the actions of hypertrophic preconditioning,whereas genetic ablation of SIRT3 in mice blocked the cardioprotective effects of hypertrophic preconditioning.The present study identifies hypertrophic preconditioning as a novel endogenous self-defensive and cardioprotective strategy for cardiac I/R injury that induces IDH2 deacetylation through a SIRT3-dependent mechanism.A therapeutic strategy targeting IDH2 may be a promising treatment for cardiac ischemic injury.

Cardioprotective effects of anesthetic preconditioning in rats with ischemia-reperfusion injury: propofol versus isoflurane

Objective： We compare the cardioprotective effects of anesthetic preconditioning by propofol and/or isoflurane in rats with ischemia-reperfusion injury. Methods： Male adult Wistar rats were subjected to 60 min of anterior descending coronary artery occlusion followed by 120 rain of reperfusion. Before the long ischemia, anesthetics were administered twice for 10 min followed by 5 min washout. Isoflurane was inhaled at 1 MAC （0.016） in I group, whereas propofol was inhaled intravenously at 37.5 mg/（kg.h） in P group. A combination ofisoflurane and propofol was administered simultaneously in I＋P group. Results： In control （without anesthetic preconditioning, C group）, remarkable myocardial infarction and apoptosis accompanied by an increased level of cardiac troponin T were noted 120 min aider ischemia-reperfusion. As compared to those of control group, I and P groups had comparable cardioprotection. In addition, I＋P group shares with I and P groups the comparable cardioprotective effects in terms of myocardial infarction and cardiac troponin T elevation. Conclusion： A combination of isoflurane and propofol produced no additional cardioprotection.

Antioxidant properties of magnesium lithospermate B contribute to the cardioprotection against myocardial ischemia/reperfusion injury in vivo and in vitro

OBJECTIVE： To determine the cardioprotective ef- fect of magnesium lithospermate B （MLB） on myo- cardial ischemia/reperfusion （MI/R） injury and to in- vestigate the antioxidant potential in vivo and in vitro. METHODS： MI/R injury was induced by the occlu- sion of left anterior descending coronary artery for 30 min followed by reperfusion for 3 h in rats. After reperfusion, hearts were harvested to assess infarct size, histopathological damages, the levels of superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GPx）, reduced glutathione （GSH） and malondialdehyde （MDA）. Blood samples were collected to determine serum levels of creatine kinase-MB （CK-MB）, cardiac troponin （cTnl） and lactate dehydrogenase （LDH）. Furthermore, simulatedischemia/reperfusion （SI/R） injury in vitro was established by oxygen and glucose deprivation （OGD） for 2 h followed by 24-hour recovery period in cardiomyocytes. The activity of LDH in the cultured su- pernatant and the levels of intracellular reactive oxygen species （ROS）, SOD and MDA in cardiomyo- cytes were also measured. Finally, cardiomyocytes apoptosis was determined with flow cytometry. RESULTS： MLB significantly limited infarct size, ameliorated histopathological damages and prevented leakage of CK-MB, cTnl and LDH. Additional- ly, SOD, CAT, GPx and GSH activities were notably increased by MLB, along with the MDA content decreased as compared with the model group in rats. In vitro study, MLB also decreased LDH activity in the cultured supernatant, increased SOD activity in cardiomyocytes, reduced intracellular ROS and MDA levels, and significantly suppressed cardiomyocytes apoptosis. CONCLUSION： MLB possessed remarkably cardioprotective effects on MI/R injury in vivo and in vitro. The protection of MLB may contribute to its antioxidant properties.

Salusins protect myocardium against ischemic injury by alleviating endoplasmic reticulum stress

Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating glucose-regulated protein 78 （GRP78）, an endoplasmic reticulum （ER） resident protein whose overexpression acts as a marker and suppressor of ER stress. The present study examined whether salusin-α and -β inhibit ER stress in ischemic myocardium. In a rat model of myocardial infarction created by ligating the left anterior descending coronary artery （LAD）, salusin-α or -β was intravenously injected at 5 or 15 nmol kg-1 15 min prior to 2 h of LAD occlusion. The high dose of salusin-α and -β3 significantly improved heart function and hemodynamics in LAD-occluded rats, but had no effects in sham-operated rats. The arrhythmias caused by LAD oc- clusion were markedly attenuated by salusin-α and -β. The apoptotic rate in ischemic myocardium was reduced from 31.5%±3.7% to 19.8%±2.2% and 12.3%±2.2%, and the infarct size was reduced from 53.4%±4.0% of the risk area to 26.5%±9.7% and 23.7%±8.9% by 15 nmol kg-1 salusin-α and -β, respectively. Furthermore, salusin-α and -β prevented the ac- tivation of GRP78 and ER stress-specific apoptotic effectors caspase-12 and CHOP （C/EBP homologous protein）, and attenu- ated the reduction of an ER stress-associated antiapoptotic protein Bcl-2 in ischemic cardiac tissue. The salusins also inhibited the ER stress induced by tunicamycin in cultured rat H9c2 cardiomyocytes. These results indicate that salusins protect myo- cardium against ischemic injury by inhibiting ER stress and ER stress-associated apoptosis.

Protective effects of Yindanxinnaotong capsule in a rat model of myocardial ischemia/reperfusion injury

OBJECTIVE: To investigate the effects of Yindanxinnaotong capsule(YDXNTC) and main components compatibility and ratios on myocardium against ischemia/reperfusion injury and the effect's underlying mechanism.METHODS: Myocardial ischemia/reperfusion injury(MIRI) was induced by ischemia for 30 min and reperfusion for 30 min. Electrocardiogram data and coronary flow were recorded, and superoxide dismutase(SOD), malondialdehyde(MDA), lactate dehydrogenase, creatine kinase-MB, cardiac troponin T and I(cT nT, cT n I) and interleukin-1β, interleukin-8,interleukin-18(IL-1β, IL-8, IL-18) in myocardium were measured. Hypoxia/reoxygenation and hydrogen peroxide(H2O2) injury were induced by hypoxia for 3 h/reoxygenation for 2 h, and 100 μM H2O2 for 1 h, respectively, in vitro rat myocardial cells(H9c2). Cell viability, SOD, MDA, cT nT and inflamma-tory factors(IL-1β, IL-8 and IL-18) were determined,and Toll-like receptor 4(TLR-4) expression was measured by western blotting.RESULTS: In the isolated heart experiment, elevated heart function, coronary flow and SOD levels,and decreased MDA levels and inflammatory factors were noted in the YDXNTC, main components and main components compatibility groups. Ventricular tachycardia/ventricular fibrillation occurrence decreased in the ginkgo biloba extract(GBE),and GBE and salvia miltiorrhiza ethanol extract compatibility(SM-E, GSEC) groups. Lactic dehydrogenase levels decreased in the YDXNTC and aqueous extract of salvia miltiorrhiza(SM-H) groups. Creatine kinase-MB decreased with GBE, SM-E, SM-H and GSEC treatment, and cT n I and cT nT levels decreased with GSEC. In the in vitro cell study,YDXNTC and main components ratios improved cell viability and SOD levels, and suppressed MDA,cT nT and inflammatory factors. TLR-4 expression was down-regulated.CONCLUSION: YDXNTC and main components compatibility showed protective effects on MIRI in this rat model and in vitro study. Regulating the Toll-like receptor signaling pathway may affect the mechanism.

Effect of electroacupuncture preconditioning at “Nèiguān” (内关 PC 6) on gene expression of myocardial opioid receptors in rats with ischemia-reperfusion

Objective To explore protective effects of electroacupuncture at ＂Nèiguān＂ （内关 PC 6） for preconditioning on myocardial ischemia-reperfusion injury （MIRI） and the mechanisms involved. Methods Forty-eight male Wistar rats were randomly divided into a sham operation group （Group N）, a MIRI group （Group M） and an electroacupuncture （EA） group （Group E）. The MIRI model was established by ligating the left anterior descending artery （LAD） for 30 min followed by reperfusion for 120 min. Partition sutures were passed under LAD without ligation for rats in Group N. Rats in Group E were pretreated with electroacupuncture （EA） applied at bilateral ＂Nèiguān＂ （内关 PC 6） for 20 min once a day for 3 consecutive days before ischemia. The infarct size plus the area at risk was evaluated by 2,3,5-triphenyltetrazolium chloride staining, and serum isoenzyme of creatine kinase （CK-MB） and lactate dehydrogenase （LDH） levels were measured by biochemical methods. Myocardium morphological changes were observed under light microscopy. The mRNA expressions of myocardial δ and κ opioid receptors （DOR and KOR） were tested by real-time RT-PCR measurements. Results The myocardial infarct size in Group E was more significantly decreased than that in Group M （P0.05）. The levels of CK-MB [（980？±？92） U/L] and LDH [（2743？±？124） U/L] in Group M were significantly higher than those in Group N [（312？±？41） U/L] and [（530？±？56） U/L], respectively （both P0.01）. The levels of CK-MB [（572？±？70） U/L] and LDH [（1819？±？97） U/L] in Group E were significantly lower than those in Group M （both P0.01）. There were no significant differences in mRNA expressions of DOR and KOR between Group M and Group N （both P0.05）, but DOR expression in Group E was significantly higher than that either in Group M or in Group N （both P0.01 ）. No significant differences were found in KOR expression among the three groups （all P0.05）. Conclusion Up-regulation of expression of δ opioid receptors may be involved in protective effects of EA at Nèiguān （内关 PC 6） for preconditioning on MIRI.