Stroke is one of the leading causes of death and disability worldwide.However,information on stroke-related tongue coating microbiome(TCM)is limited,and whether TCM modulation could benefit for stroke prevention and r...Stroke is one of the leading causes of death and disability worldwide.However,information on stroke-related tongue coating microbiome(TCM)is limited,and whether TCM modulation could benefit for stroke prevention and rehabilitation is unknown.Here,TCM from stroke patients(SP)was characterized using molecular techniques.The occurrence of stroke resulted in TCM dysbiosis with significantly reduced species richness and diversity.The abundance of Prevotella,Leptotrichia,Actinomyces,Alloprevotella,Haemophilus,and TM7_[G-1]were greatly reduced,but common infection Streptococcus and Pseudomonas were remarkably increased.Furthermore,an antioxidative probiotic Lactiplantibacillus plantarum AR113 was used for TCM intervention in stroke rats with cerebral ischemia/reperfusion(I/R).AR113 partly restored I/R induced change of TCM and gut microbiota with significantly improved neurological deficit,relieved histopathologic change,increased activities of antioxidant enzymes,and decreased contents of oxidative stress biomarkers.Moreover,the gene expression of antioxidant-related proteins and apoptosis-related factors heme oxygenase-1(HO-1),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),nuclear factor erythroid 2-related factor 2(Nrf2),NAD(P)H:quinone oxidoreductase-1(NQO-1),and Bcl-2 was significantly increased,but cytochrome C,cleaved caspase-3,and Bax were markedly decreased in the brain by AR113 treatment.The results suggested that AR113 could ameliorate cerebral I/R injury through antioxidation and anti-apoptosis pathways,and AR113 intervention of TCM may have the application potential for stroke prevention and control.展开更多
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...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.展开更多
Background Ischemia/reperfusion injury （IRI） is an inflammatory response that occurs when tissue is reperfused following a prolonged period of ischemia. Several studies have indicated that C-reactive protein （CRP）...Background Ischemia/reperfusion injury （IRI） is an inflammatory response that occurs when tissue is reperfused following a prolonged period of ischemia. Several studies have indicated that C-reactive protein （CRP） might play an important role in inducing IRI. However, the effects of CRP on myocardial IRI and the underlying mechanisms have not been fully elucidated. This study aimed to investigate the association between CRP and myocardial IRI and the underlying mechanisms. Methods We simulated ischemia/reperfusion using oxygen-glucose deprivation/ reoxygenation （OGD/R） in neonatal Sprague-Dawley rat cardiomyocytes; reperfusion injury was induced by three hours of hypoxia with glucose and serum deprivation followed by one hour of reperfusion. Cell viability was tested with MTS assays, and cardiomyocyte damage was evaluated by lactate dehydrogenase （LDH） leakage. Mitochondrial membrane potential was measured using tetramethylrhodamine ethyl ester （TMRE） and mitochondrial permeability transition pore （mPTP） opening was measured using calcein/AM; both TMRE and caocein/AM were visualized with laser scanning confocal microscopy. In addition, we studied the signaling pathways underlying CRP-mediated ischemia/reperfusion injury via Western blot analysis. Results Compared with the simple OGD/R group, after intervention with 10 pg/mL CRP, cell viability decreased markedly （82.36 % ± 6.18% vs. 64.84% ± 4.06%, P = 0.0007）, and the LDH leakage significantly increased （145.3 U/L ± 16.06 U/L vs. 208.2 U/L ± 19.23 U/L, P = 0.0122）. CRP also activated mPTP opening and reduced mitochondrial membrane potential during myocardial ischemia/reperfusion. Pretreatment with 1 pM atorvastatin （Ator） before CRP intervention protected cardiomyocytes from IRI. Mitochondrial KATP channel opener diazoxide and mPTP inhibitor cyclosporin A also offset the effects of CRP in this process. The level of phosphorylated extracellular-signal-regulated kinase （ERK） 1/2 was significantly higher after pre-treatment with CRP compared with the OGD/R group （170.4% ± 3.00% v.v. 93.53% ± 1.94%, P 〈 0.0001）. Western blot analysis revealed that Akt expression was markedly activated （184.2% ± 6.96% vs. 122.7% ± 5.30%, P = 0.0003） and ERK 1/2 phosphorylation significantly reduced after co-treatment with Ator and CRP compared with the level after CRP pretreatment alone. Conclusions Our results suggested that CRP directly aggravates myocardial IRI in myocardial cells and that this effect is primarily mediated by inhibiting mitochondrial ATP- sensitive potassium （mitoKATp） channels and promoting mPTP opening. Ator counteracts these effects and can reduce CRP-induced IRI. One of the mechanisms of CRP-induced IRI may be related to the sustained activation of the ERK signaling pathway.展开更多
BACKGROUND:We aimed to investigate the gene expression of myocardial ischemia/reperfusion injury(MIRI)in patients with acute ST-elevation myocardial infarction(STEMI)using stress and toxicity pathway gene chip technol...BACKGROUND:We aimed to investigate the gene expression of myocardial ischemia/reperfusion injury(MIRI)in patients with acute ST-elevation myocardial infarction(STEMI)using stress and toxicity pathway gene chip technology and try to determine the underlying mechanism.METHODS:The mononuclear cells were separated by ficoll centrifugation,and plasma total antioxidant capacity(T-AOC)was determined by the ferric reducing ability of plasma(FRAP)assay.The expression of toxic oxidative stress genes was determined and verified by oligo gene chip and quantitative real-time polymerase chain reaction(qRT-PCR).Additionally,gene ontology(GO)enrichment analysis was performed on DAVID website to analyze the potential mechanism further.RESULTS:The total numbers of white blood cells(WBC)and neutrophils(N)in the peripheral blood of STEMI patients(the AMI group)were significantly higher than those in the control group(WBC:11.67±4.85×10^(9)/L vs.6.41±0.72×10^(9)/L,P<0.05;N:9.27±4.75×10^(9)/L vs.3.89±0.81×10^(9)/L,P<0.05),and WBCs were significantly associated with creatine kinase-myocardial band(CK-MB)on the first day(Y=8.945+0.018X,P<0.05).In addition,the T-AOC was significantly lower in the AMI group comparing to the control group(12.80±1.79 U/mL vs.20.48±2.55 U/mL,P<0.05).According to the gene analysis,eight up-regulated differentially expressed genes(DEGs)included GADD45A,PRDX2,HSPD1,DNAJB1,DNAJB2,RAD50,TNFSF6,and TRADD.Four down-regulated DEGs contained CCNG1,CAT,CYP1A1,and ATM.TNFSF6 and CYP1A1 were detected by polymerase chain reaction(PCR)to verify the expression at different time points,and the results showed that TNFSF6 was up-regulated and CYP1A1 was down-regulated as the total expression.GO and kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis suggested that the oxidative stress genes mediate MIRI via various ways such as unfolded protein response(UPR)and apoptosis.CONCLUSIONS:WBCs,especially neutrophils,were the critical cells that mediating reperfusion injury.MIRI was regulated by various genes,including oxidative metabolic stress,heat shock,DNA damage and repair,and apoptosis-related genes.The underlying pathway may be associated with UPR and apoptosis,which may be the novel therapeutic target.展开更多
BACKGROUND:Hyperbaric oxygen(HBO)is an effective adjuvant therapy for ischemiareperfusion(I/R)injury of the brain,small intestine and testis in addition to crushing injury.Studies have shown that HBO increases the act...BACKGROUND:Hyperbaric oxygen(HBO)is an effective adjuvant therapy for ischemiareperfusion(I/R)injury of the brain,small intestine and testis in addition to crushing injury.Studies have shown that HBO increases the activity of villi of the ileum 30 minutes after I/R injury.The present study aimed to observe the effect of HBO on apoptosis of epithelial cells in the small intestine during different periods of I/R and to elucidate the potential mechanisms.METHODS:Rats were subjected to 60-minute ischemia by clamping the superior mesenteric artery and 60-minute reperfusion by removal of clamping.The rats were randomly divided into four groups:I/R group,HBO precondition or HBO treatment before ischemia(HBO-P),HBO treatment during ischemia period(HBO-I),and HBO treatment during reperfusion(HBO-R).After 60-minute reperfusion,samples of the small intestine were prepared to measure the level of ATP by using the colorimetric method and immunochemical expression of caspase-3.The levels of TNF-αin intestinal tissue were measured using the enzyme-linked immunosorbent assay method(Elisa).RESULTS:TNF-αlevels were significantly lower in the HBO-I group than in the HBO-P(P<0.05),HBO-R and I/R groups;there was no significant difference between the HBO-R and I/R groups(P>0.05).The expression of caspas-3 was significantly lower in the HBO-I group than in the HBO-P group(P<0.05);it was also significantly lower in the HBO-P group than in the I/R and HBO-R groups(P<0.05).ATP level was significantly lower in the HBO-I group than in the HBO-P group(P<0.05),and also it was significantly lower in the HBO-P group than in the I/R and HBO-R groups(P<0.05).CONCLUSIONS:There is an association between HBO,small intestinal I/R injury,and mucosa apoptosis.HBO maintains ATP and aerobic metabolism,inhibites TNF-αproduction,and thus prevents intestinal mucosa from apoptosis.Best results can be obtained when HBO is administered to patients in the period of ischemia,and no side effects are produced when HBO is given during the Period of Reperfusion.展开更多
Objective Oxidative stress （OS） plays a crucial role in ischemic stroke. Grape seed procyanidin extract （GSPE） was reported to be a critical regulator of OS. We hypothesized that GSPE might also be protective in...Objective Oxidative stress （OS） plays a crucial role in ischemic stroke. Grape seed procyanidin extract （GSPE） was reported to be a critical regulator of OS. We hypothesized that GSPE might also be protective in ischemia-reperfusion brain injury. This study aimed to explore whether GSPE administration can protect mice from ischemia-reperfusion brain injury. Methods Transient middle cerebral artery occlusion （MCAO） was conducted followed by reperfusion for 24 hours to make ischemia-reperfusion brain injury in mice that received GSPE （MCAOG, n=60） or normal saline （MCAONS, n=60）. Sham-operated mice （GSPE group and normal saline group） were set as controls. The neurological severity score （NSS） was used to evaluate neural function impairment 1 hour, 24 hour, 3 days and 7 days after MCAO. Mice underwent brain T2WI imaging with a 3T animal MRI scanner 24 hours after reperfusion, and the stroke volume of brains were calculated according to abnormal signal intensity. Immunohistopathological analysis of brain tissues at 24 h after reperfusion was performed for neuronal nuclear antigen （NeuN）, CD34, Bcl-2, and Bax. Glutathione peroxidation （GSH-Px） activity and the level of malonaldehyde （MDA） of brain tissue were also examined. The above indexes were compared among the groups statistically.Results Significant functional improvement was observed 24 hours after MCAO in MCAOG group compared to MCAONS group （P〈0.05）. MCAOG group had smaller cerebral stroke volume （22.46 ± 11.45 mm3 vs. 47.84±9.06 mm3, P〈0.05） than MCAONS group 24 hours after MCAO. More mature NeuN-immunoreactive neurons and more CD34-positive cells in peri-infarct zones were observed in brain tissue of MCAOG mice 24 h after MCAO than that of MCAONS mice （both P〈0.05）. MCAONS mice had significantly higher number of Bax-positive cells in brain tissue than MCAOG （P〈0.05）. The mean MDA level was significantly lower （P〈0.05） and the GSH-Px activity was significantly higher （P〈0.05） in brains of MCAOG mice compared to those of MCAONS mice. Conclusion GSPE administration protects mice from ischemia-reperfusion brain injury through attenuating oxidative stress and apoptosis, promoting angiogenesis, and activating antioxidant enzyme GSH-Px. GSPE may represent a new therapeutical direction for the treatment of ischemia-reperfusion brain injury.展开更多
Objective To study the protective effect of agrimony extracts from different extracting methods on cerebral ischemia-reperfusion injury in rats, in order to optimize the extraction scheme of agrimony.Methods Male rats...Objective To study the protective effect of agrimony extracts from different extracting methods on cerebral ischemia-reperfusion injury in rats, in order to optimize the extraction scheme of agrimony.Methods Male rats were randomly assigned into seven groups: 1. Sham-operated group, 2. Untreated MCAO group (MCAO), 3. Petroleum ether extract of Agrimonia pilosa treated MCAO group (PEA), 4. Ethyl acetate extract of Agrimonia pilosa treated MCAO group (EAEA), 5. Ethanol extract of Agrimonia pilosa treated MCAO group (EEA), 6. Water extract of Agrimonia pilosa treated MCAO group (WEA), 7. Nimodipine treated MCAO group (NP). Intragastrical drug administration (i.g) was performed at 0 and 6 hours after MCAO.Neurological function tests were performed after reperfusion for 24 hours, then the brain was removed for the evaluations of the cerebral infarction volume (percentage of total brain volume) by immunohistochemistry,histological changes (hematoxylin-eosin staining), Na+/K+-ATPase, Ca2+-ATPase (modified method of Svoboda and Mosinger), mRNA expression of Tumor suppressor gene (P53) and hot shock protein (HSP70)(quantitative real-time PCR).Results The neurological function of MCAO group had significantly higher scores than the sham group (P<0.01). The WEA group showed a significantly lower neurological score than the MCAO group (P<0.05),indicating the protective effect of WEA on neurological deficits. The mean infarction volumes of WEA (13.5±6.6%, F=4.75, P<0.01), EEA (19.90±6.90%, F=5.23, P<0.01), PEA (20.40±5.30%, F=4.68,P<0.01) and EAEA (22.50±10.50%, F=6.25, P<0.05) group were all significantly smaller than that of MCAO group (29.40±6.50%). HE staining demonstrated that, compared to the treated groups, the infarcted cerebral tissue of MCAO group had more swelling neural cells, lighter stained nucleus, fewer and irregularly distributed neurons. The activity of Na+/K+-ATPase and Ca2+-ATPase reduced in the MCAO group (3.67±0.48 U/mg,1.28±0.26 U/mg, respectively), and were significantly higher in WEA group (7.56±0.85 U/mg, F=12.65,P=0.010; 3.59±0.22 U/mg, F=8.32, P=0.041, respectively). The MCAO group showed significantly elevated P53 and HSP70 mRNA expressions compared to the sham group (P<0.01, P<0.05). P53 mRNA expressions in Agrimony extracts treated groups were significantly lower than that of the MCAO group (all P<0.01), with the WEA group showing the greatest difference from MCAO group. The HSP70 mRNA level of the treated groups were not significantly different from that of the MCAO group.Conclusions Treatment using water extracts of agrimony can promote the best functional and metabolic recovery for rat model of cerebral ischemia-reperfusion injury, which maybe relate with the upregulation of energy metabolism in nerve cells after MCAO.展开更多
Objective： To investigate whether remifentanil induced cardioprotecting effect is associated with expression of toll-like receptor 4 （TLR4）, nuclear factor rB （NF-r.B） and serum interleukin -6 （IL-6）. Methods：...Objective： To investigate whether remifentanil induced cardioprotecting effect is associated with expression of toll-like receptor 4 （TLR4）, nuclear factor rB （NF-r.B） and serum interleukin -6 （IL-6）. Methods： Fifty rabbits were randomly divided into 5 groups （n=10） according to the treatment： sham operation group （group A）, ischemla-reperfusion group （group B）, low-dose remifentanil group （group C）, mediate-dose remifentanil group （group D）, and high-dose remlfentanil group （group E） Myocardial TLR4 mRNA levels, NF-r.B protein expression and serum levels of IL-6 were observed in 120 min after reperfusion. Results： The myocardial expressions of TLR4 mRNA, NF-rd3 protein and IL-6 level in sera of groups B, C, D and E were elevated compared with group A. However, remifentanil significantly reduced the levels of TLR4 mRNA, NF- r.B protein expression and serum IL-6 in groups C, D and E compared with group B. There were remarkable differences between the groups （P〈O.O1）. Conclusion： Intravenous remifentanil has protective effect against rabbit myocardial ischemia/reperfusion injury. This effect may be associated with TLR4, NF-r.B expressions on myocytes and serum level of IL-6 in a dose-dependent manner展开更多
The effect of myocardium being subjected to 60 min ischemia and 60 min reperfusion incat cardiopulmonary bypass on level of lipid peroxides(LPO),function of myocardial mitochon-dria and activity of superoxides dismuta...The effect of myocardium being subjected to 60 min ischemia and 60 min reperfusion incat cardiopulmonary bypass on level of lipid peroxides(LPO),function of myocardial mitochon-dria and activity of superoxides dismutase(SOD)was studied. Myocardial mitochondrial functionwas depressed slightly 60 rain after ischemia but significantly 60 min after reperfusion.Increasedlipid peroxides content and decreased activity of SOD were observed at 60 rain after ischemia.Af-ter reperfusion,the activity of SOD continued decreasing,and LPO elevated still further.Theseresults support the hypothesis that free radicals may contribute to myocardial reperfusion injury.展开更多
It is known that reperfusion injury occurs after reperfusion with normal blood in ischemic myocardium. Using the cat cardiopulmonary bypass model, this study documented that myocardial mitochondrial function was sigmf...It is known that reperfusion injury occurs after reperfusion with normal blood in ischemic myocardium. Using the cat cardiopulmonary bypass model, this study documented that myocardial mitochondrial function was sigmficantly depressed 60min after reperfusion, but was only slightly depressed in the controlled reperfusion group. Significantly increased MDA content and decreased activity of SOD was observed 60 min after reperfusion, whereas in the controlled reperfusion group, the MDA content was low and the activity of SOD was protected. These results indicate that controlled reperfusion with warm blood cardioplegia containing mannitol after ischemia provides benefit in avoiding myocardial mitochondrial reperfusion injury by preventing or reducing a potentially harmful component of reperfusion.展开更多
objective: To investigate the changes of spinal cord blood flow (SCBF) after the ischemia and reperfusion injury of the spinal cord and its relation with pathological damages. Methods: Twenty adult Japanese big-ear wh...objective: To investigate the changes of spinal cord blood flow (SCBF) after the ischemia and reperfusion injury of the spinal cord and its relation with pathological damages. Methods: Twenty adult Japanese big-ear white rabbits equally randomized into the control group, 30-min-ischemic group, 60-min-is chemic group and 90-min-ischemic group. All the rabbits in the latter 3 groups were inflicted with the is chemia and reperfusion injury of the spinal cord through selective occlusion of the lumbar artery. SCBF was measured with the hydrogen clearance method and the pathological changes of the injured spinal cord were observed with Nissl’s staining. Results: SCBF during ischemia was 0 ml/100 g/min. During reperfusion, it was recovered to different levels. However, it was still decreased as compared with that before ischemia and that in the control group. The pathological changes of the gray matter were the most significant. The severi ty of the pathological changes decreased in the order from 90-min-ischemic group, 6O-min-ischemic group to 30-min ischemic group. Conclusion: Reversible injury occurs in rabbits after ischemia for 30 min, irreversible injury in those after ischemia for 90 min and partially reversible injury in those after ischemia for 60 min.展开更多
Objective To elucidate whether endoxin is one of important factors involved in myocardial ischemia reperfusion (MIR) injury, the change of myocardial endoxin level was determined in rats with MIR injury model and the ...Objective To elucidate whether endoxin is one of important factors involved in myocardial ischemia reperfusion (MIR) injury, the change of myocardial endoxin level was determined in rats with MIR injury model and the effects of anti-digoxin antiserum (ADA), an endoxin specific antagonist, on MIR injury were studied. Methods MIR injury model was obtained by ligating left anterior descending coronary artery 30 min followed by 45 min reperfusion. Sprauge Dawley rats were randomly divided into six groups of 10 rats, each. Sham group, MIR group, normal saline group, ADA 9, 18 and 36 mg/kg. ECG was continuously recorded. After reperfusion left ventricular myocardium samples of ischemic area were processed immediately. Myocardial endoxin level, Na++/K++-ATPase, Ca+{2+}-ATPase, Mg+{2+}-ATPase activities, and intramitochondrial Ca+{2+} content were measured. Results Myocardial endoxin level was significantly increased; Na++/K++-ATPase, Ca+{2+}- ATPase , and Mg+{2+}-ATPase activities were remarkably decreased; intramitochondrial Ca+{2+} content was remarkably raised; ST segments of ECG were significantly elevated and occurrence and scores of ventricular arrhythmias were significantly increased in early stage of reperfusion in rats with MIR. In all groups with ADA, myocardial endoxin level was remarkably decreased; Na++/K++-ATPase, Ca+{2+}-ATPase and Mg+{2+}-ATPase activities were drastically increased; intramitochondrial Ca+{2+} content was declined; ST segments and ventricular arrhythmias were improved. Conclusion Myocardial endoxin level was increased in MIR, which implies that the elevated endoxin may be one of major factors inducing MIR injury. This postulate is supported by the observation that ADA has protective and therapeutic effects against MIR injury probably by antagonizing the action of endoxin. The underlying mechanism may be ascribed to restoration of energy metabolism, and attenuation of intracellular Ca+{2+} overload.展开更多
The aim of this study was to determine the time course of changes in extracellular fluid (ECF) concentrations of purines, amino acids, monoamines, and their metabolites in the striatum of rats during ischemia and repe...The aim of this study was to determine the time course of changes in extracellular fluid (ECF) concentrations of purines, amino acids, monoamines, and their metabolites in the striatum of rats during ischemia and reperfusion, using intracerebral microdialysis as the sampling technique. In rats subjected to 20 min forebrain ischemia by four-vessel occlusion, the concentrations of adenosine (Ade), inosine (Ino) and hypoxanthine (Hyp) were found to rise markedly. These changes were accompanied by dramatically elevated levels of aspartate (Asp), glutamate (Glu), taurine (Tau), γ-aminobutyric acid (GABA), dopamine (DA) and norepinephrine (NE), all of which gradually returned to baseline following reperfusion. Concomitantly, the levels of metabolite 3, 4-dihydroxyphenylacetic acid (DOPAC) . homovanillic acid (HVA), 5-hydroxyindole-3-acetic acid (5-HIAA) and xanthine (Xan) decreased during ischemia and gradually recovered 60～ 90 min after reperfusion. It was concluded that during global brain ischemia, the ECF is flooded with both potentially harmful (e. g. Asp, Glu, DA) and protective (e. g. Tau, GABA, Ade) agents.展开更多
Objective: To study the changes of oxygen free radical, expression of apoptotic gene, ultrastructure of myocardial cell and second injury of the heart following the intestinal ischemia and reperfusion. Methods: Making...Objective: To study the changes of oxygen free radical, expression of apoptotic gene, ultrastructure of myocardial cell and second injury of the heart following the intestinal ischemia and reperfusion. Methods: Making the models of ischemia and reperfusion by clamping superior mesenteric artery, the concentration of NO and SOD in the blood was examined before clamping the artery and reperfusion for 0, 30, 60 min, 1, 3, and 7 d. The expression of Bax, Bal-2, and p53 in myocardial cell was studied by means of immunohistochemical SP method and the microstructure damage was observed under electron microscopy. Results: After clamping the superior mesenteric artery and reperfusion the concentration of NO increased continuously and reached a peak for reperfusion 7 d (P<0.01) but that of SOD decreased from 30 min to 7 d. The expression of Bax, p53 and Bcl-2 also increased obviously especially for reperfusion 30 min and 7 d following ischemia and reperfusion. After reperfusion for 30 min the positive cell rate of Bax, p53 and Bcl-2 was 53.6%, 45.9% and 67.9%, for reperfusion 7 d it was 52.4%, 43.4% and 31.9% respectively, but the positive cell rate of Bax and p53 was higher than that of Bcl-2. The result of electron microscopy observation showed mfofiliments breaked, dissolved and chromatin condensed. Conclusion: Intestinal ischemia and reperfusion of rat can induced the changes of oxygen free radical and the expression of apoptotic gene and second injury of myocardial cells.展开更多
BACKGROUND:Recent studies have showed that S100A8 has been implicated in the pathobiology of inflammatory disorders,and that cerebral ischemia reperfusion(l/R) rapidly activates inflammation responses via Toll-like re...BACKGROUND:Recent studies have showed that S100A8 has been implicated in the pathobiology of inflammatory disorders,and that cerebral ischemia reperfusion(l/R) rapidly activates inflammation responses via Toll-like receptor 4(TLR4).This study aimed to explore the expression of S100A8 and the relationship between S100A8 and TLR4 in focal cerebral ischemia reperfusion injury.METHODS:C3H/HeJ mice(n=30) and C3H/HeN mice(n=30) were divided randomly into a C3H/HeJ model group(n=18),a C3H/HeJ control group(n=12),a C3H/HeN model group(n=18),and a C3H/HeN control group(n=12).Middle cerebral artery l/R model in mice was produced using a thread embolism method.The brains of the mice were collected after ischemia for 1 hour and reperfusion for 12 hours.Stroke outcome was evaluated by determination of infarct volume and assessment of neurological impairment scores.Brain injury after cerebral l/R was observed by an optical microscope after TTC and HE dyeing.The immunofluorescence technique and real time PCR were used to test the expression level of S100A8 in brain damage.RESULTS:Compared with C3H/HeN mice,TLR4-deficient mice(C3H/HeJ) had lower infarct volumes and better outcomes in neurological tests.The levels of S100A8 increased sharply in the brains of mice after l/R injury.In addition,mice that lacked TLR4(C3H/HeJ) had lower expression of l/R-induced S100A8 than C3H/HeN mice in the model group,indicating that a close relationship might exist between the levels of S100A8 and TLR4.CONCLUSION:S100A8 interaction with TLR4 might be involved in brain damage and in inflammation triggered by l/R injury.展开更多
Objective To study the protecting effects and mechanism of betaine hydrochloride on hepatic ischemia-reperfusion injury in rats.Methods Fourty SD rats were randomly divided into 5 groups(8 animals in each group):sham-...Objective To study the protecting effects and mechanism of betaine hydrochloride on hepatic ischemia-reperfusion injury in rats.Methods Fourty SD rats were randomly divided into 5 groups(8 animals in each group):sham-operated control group(A),hepatic ischemia-reperfusion group(B),200 mg·kg-1 400 mg·kg-1 800 mg·kg-1 betaine hydrochloride+hepatic ischemia-reperfusion group(C、D、E).betaine hydrochloride was administered to animals byoral route in group C、D、E for 7 days before ischemia.A、B group was administered with NS.Made the animal model of part hepatic ischemia-reperfusion.Serum alanine aminotransferase(ALT),aspartate aminotransferase(AST)levels in the blood and themalondialdehyde(MDA),superoxide dismutase(SOD),protein content in hepatic tissue were determined after the liver had been reperfused for 24 hours;the hepatic tissue was examined under lightmicroscope and the cell apoptosis was demonstrated with flow cytometry.Results ALT,AST,MDA increased and SOD decreased significantly in B group when compared those in the A group(P<0.05),Hepatic apoptosis was significantly increased;ALT,AST,MDA decreased and SOD increased significantly in betaine hydrochloride 200 mg·kg-1(C)group when compared those in the B group(P<0.05).Hepatic apoptosis was significantly lower,The histologic changes of the liver tissue under lightmicroscope in the C group was more easer than in the I/R group(B).Conclusions Betaine hydrochloride has the ability to scavenge oxygen free radical(OFR),reduce lipid peroxidation and inhibition of apoptosis.So it can protect the rats liver damaged by ischemia-reperfusion.展开更多
Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whe...Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whether pretreatment with monoclonal antibody against TNF-α (TNF-α MoAb) would affect the release of D(-)-lactate after local gut ischemia followed by reperfusion. Methods Anesthetized Sprague-Dawley rats underwent superior mesenteric artery occlusion for 75 min followed by reperfusion for 6 hr. The rats were treated intravenously with either TNF-α MoAb (20 mg/kg) or albumin (20 mg/kg) 30 min prior to the onset of ischemia. Plasma D(-)-lactate levels were measured in both the portal and systemic blood by an enzymatic spectrophotometric assay. Intestinal TNF-αmRNA expression as well as protein levels were also measured at various intervals. In addition, a postmortem examination was performed together with a macropathological evaluation based on a four-grade scoring system.Results Intestinal ischemia resulted in a significant elevation in D(-)-lactate levels in the portal vein blood in both the control and treatment groups ( P ＜0.05). However, animals pretreated with TNF-α MoAb at 6 hr after reperfusion showed significant attenuation of an increase in both portal and systemic D(-)-lactate levels when compared with those only receiving albumin (P ＜ 0.05). In the control animals, a remarkable rise in intestinal TNF-α level was measured at 0.5 hr after clamp release ( P ＜ 0.01); however, prophylactic treatment with TNF-α MoAb completely annulled the increase of local TNF-α levels seen in the control animals. Similarly, after anti-TNF-α MoAb administration, intestinal TNF-α mRNA expression was markedly inhibited, which showed significant differences when compared with the control group at 0.5 hr, 2 hr and 6 hr after the release of occlusion ( P ＜ 0.05-0.01 ). In addition, the pathological examination showed marked intestinal lesions that formed during ischemia, which were much worse upon reperfusion,particularly at the 6 hr time point. These acute injuries were obviously attenuated in animals receiving TNF-α MoAb.Conclusions It appeared that acute intestinal ischemia was associated with failure of the mucosal barrier, resulting in increased plasma D(-)-lactate levels in both portal and systemic blood. These results suggest that TNF-α appears to be involved in the development of local damage associated with intestinal ischemic injury. Moreover, prophylactic treatment with TNF-α MoAb exerts preventive effects on ischemia/ reperfusion-induced circulating D (-)-lactate elevation and gut injury. ( J Geriatr Cardiol 2004;1(2):119-124. )展开更多
BACKGROUND: Rapid and complete reperfusion has been widely adopted in the treatment of patients with acute myocardial infarction(AMI), but this process sometimes can cause severe reperfusion injury. This study aimed t...BACKGROUND: Rapid and complete reperfusion has been widely adopted in the treatment of patients with acute myocardial infarction(AMI), but this process sometimes can cause severe reperfusion injury. This study aimed to investigate different patterns of post-conditioning in acute myocardial ischemia-reperfusion injury, and to detect the role of mitogen activated protein kinase(MAPK) during the injury.METHODS: Rats were randomly divided into five groups: sham group, reperfusion injury(R/I) group, gradually decreased reperfusion group(GDR group, 30/10-25/15-15/25-10/30 seconds of reperfusion/ischemia), equal reperfusion group(ER group, 20/20 seconds reperfusion/ischemia, 4 cycles), and gradually increased reperfusion group(GIR group, 10/30-15/25-25/15-30/10 seconds of reperfusion/ischemia). Acute myocardial infarction and ischemic post-conditioning models were established in the rats. Six hours after reperfusion, 3 rats from each group were sacrificed and myocardial tissues were taken to measure the expressions of phosphorylation of extracellular signalregulated protein kinase(P-ERK), phosphorylated c-Jun N-terminal kinase(P-JNK), mitogen-activated protein kinase p38(p38 MAPK), tumor necrosis factor-α(TNF-α), caspases-8 in the myocardial tissue, and cytochrome c in the cytosol using Western blot. Hemodynamics was measured at 24 hours after reperfusion, the blood was drawn for the determination of cardiac enzymes, and the heart tissue was collected for the measurement of apoptosis using TUNEL. One-way analysis of variance and the Q test were employed to determine differences in individual variables between the 5 groups.RESULTS: Three post-conditioning patterns were found to provide cardioprotection(P<0.05) compared with R/I without postconditioning. GIR provided the best cardioprotection effect, followed by ER and then GDR. Apoptotic index and serum marker levels were reduced more signifi cantly in GIR than in ER(P<0.05). The enhanced cardioprotection provided by GIR was accompanied with significantly increased levels of P-ERK 1/2(1.82±0.22 vs. 1.54±0.32, P<0.05), and lower levels of p-JNK, p38 MAPK, TNF-α, caspase-8, caspase-9 and cytochrome in the cytoplasm(P<0.05), compared with ER. The infarct size was smaller in the GIR group than in the ER group, but this difference was not significant(16.30%±5.22% vs. 20.57%±6.32%, P<0.05). All the measured variables were improved more signifi cantly in the GIR group than in the GDR group(P<0.05).CONCLUSION: Gradually increased reperfusion in post-conditioning could attenuate reperfusion injury more significantly than routine method, thereby the MAPK pathway plays an important role in this process.展开更多
基金supported by National Science Fund for Distinguished Young Scholars(grant No.32025029)Shanghai Education Committee Scientific Research Innovation Project(grant No.2101070007800120)+1 种基金Clinical research project in health industry of Shanghai Municipal Health Commission(202240379)the Development Fund for Shanghai Talents(grant No.2021077).
文摘Stroke is one of the leading causes of death and disability worldwide.However,information on stroke-related tongue coating microbiome(TCM)is limited,and whether TCM modulation could benefit for stroke prevention and rehabilitation is unknown.Here,TCM from stroke patients(SP)was characterized using molecular techniques.The occurrence of stroke resulted in TCM dysbiosis with significantly reduced species richness and diversity.The abundance of Prevotella,Leptotrichia,Actinomyces,Alloprevotella,Haemophilus,and TM7_[G-1]were greatly reduced,but common infection Streptococcus and Pseudomonas were remarkably increased.Furthermore,an antioxidative probiotic Lactiplantibacillus plantarum AR113 was used for TCM intervention in stroke rats with cerebral ischemia/reperfusion(I/R).AR113 partly restored I/R induced change of TCM and gut microbiota with significantly improved neurological deficit,relieved histopathologic change,increased activities of antioxidant enzymes,and decreased contents of oxidative stress biomarkers.Moreover,the gene expression of antioxidant-related proteins and apoptosis-related factors heme oxygenase-1(HO-1),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),nuclear factor erythroid 2-related factor 2(Nrf2),NAD(P)H:quinone oxidoreductase-1(NQO-1),and Bcl-2 was significantly increased,but cytochrome C,cleaved caspase-3,and Bax were markedly decreased in the brain by AR113 treatment.The results suggested that AR113 could ameliorate cerebral I/R injury through antioxidation and anti-apoptosis pathways,and AR113 intervention of TCM may have the application potential for stroke prevention and control.
文摘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.
文摘Background Ischemia/reperfusion injury （IRI） is an inflammatory response that occurs when tissue is reperfused following a prolonged period of ischemia. Several studies have indicated that C-reactive protein （CRP） might play an important role in inducing IRI. However, the effects of CRP on myocardial IRI and the underlying mechanisms have not been fully elucidated. This study aimed to investigate the association between CRP and myocardial IRI and the underlying mechanisms. Methods We simulated ischemia/reperfusion using oxygen-glucose deprivation/ reoxygenation （OGD/R） in neonatal Sprague-Dawley rat cardiomyocytes; reperfusion injury was induced by three hours of hypoxia with glucose and serum deprivation followed by one hour of reperfusion. Cell viability was tested with MTS assays, and cardiomyocyte damage was evaluated by lactate dehydrogenase （LDH） leakage. Mitochondrial membrane potential was measured using tetramethylrhodamine ethyl ester （TMRE） and mitochondrial permeability transition pore （mPTP） opening was measured using calcein/AM; both TMRE and caocein/AM were visualized with laser scanning confocal microscopy. In addition, we studied the signaling pathways underlying CRP-mediated ischemia/reperfusion injury via Western blot analysis. Results Compared with the simple OGD/R group, after intervention with 10 pg/mL CRP, cell viability decreased markedly （82.36 % ± 6.18% vs. 64.84% ± 4.06%, P = 0.0007）, and the LDH leakage significantly increased （145.3 U/L ± 16.06 U/L vs. 208.2 U/L ± 19.23 U/L, P = 0.0122）. CRP also activated mPTP opening and reduced mitochondrial membrane potential during myocardial ischemia/reperfusion. Pretreatment with 1 pM atorvastatin （Ator） before CRP intervention protected cardiomyocytes from IRI. Mitochondrial KATP channel opener diazoxide and mPTP inhibitor cyclosporin A also offset the effects of CRP in this process. The level of phosphorylated extracellular-signal-regulated kinase （ERK） 1/2 was significantly higher after pre-treatment with CRP compared with the OGD/R group （170.4% ± 3.00% v.v. 93.53% ± 1.94%, P 〈 0.0001）. Western blot analysis revealed that Akt expression was markedly activated （184.2% ± 6.96% vs. 122.7% ± 5.30%, P = 0.0003） and ERK 1/2 phosphorylation significantly reduced after co-treatment with Ator and CRP compared with the level after CRP pretreatment alone. Conclusions Our results suggested that CRP directly aggravates myocardial IRI in myocardial cells and that this effect is primarily mediated by inhibiting mitochondrial ATP- sensitive potassium （mitoKATp） channels and promoting mPTP opening. Ator counteracts these effects and can reduce CRP-induced IRI. One of the mechanisms of CRP-induced IRI may be related to the sustained activation of the ERK signaling pathway.
基金National Natural Science Foundation of China(81670220,31270992,and 30800215)Guangdong Provincial Natural Science Foundation(2014A030313086)+2 种基金Guangdong Provincial Science and Technology Plan Project(2015A020212013)Guangzhou Science and Technology Project(201804010007)This research was approved by the Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University([2019]176).
文摘BACKGROUND:We aimed to investigate the gene expression of myocardial ischemia/reperfusion injury(MIRI)in patients with acute ST-elevation myocardial infarction(STEMI)using stress and toxicity pathway gene chip technology and try to determine the underlying mechanism.METHODS:The mononuclear cells were separated by ficoll centrifugation,and plasma total antioxidant capacity(T-AOC)was determined by the ferric reducing ability of plasma(FRAP)assay.The expression of toxic oxidative stress genes was determined and verified by oligo gene chip and quantitative real-time polymerase chain reaction(qRT-PCR).Additionally,gene ontology(GO)enrichment analysis was performed on DAVID website to analyze the potential mechanism further.RESULTS:The total numbers of white blood cells(WBC)and neutrophils(N)in the peripheral blood of STEMI patients(the AMI group)were significantly higher than those in the control group(WBC:11.67±4.85×10^(9)/L vs.6.41±0.72×10^(9)/L,P<0.05;N:9.27±4.75×10^(9)/L vs.3.89±0.81×10^(9)/L,P<0.05),and WBCs were significantly associated with creatine kinase-myocardial band(CK-MB)on the first day(Y=8.945+0.018X,P<0.05).In addition,the T-AOC was significantly lower in the AMI group comparing to the control group(12.80±1.79 U/mL vs.20.48±2.55 U/mL,P<0.05).According to the gene analysis,eight up-regulated differentially expressed genes(DEGs)included GADD45A,PRDX2,HSPD1,DNAJB1,DNAJB2,RAD50,TNFSF6,and TRADD.Four down-regulated DEGs contained CCNG1,CAT,CYP1A1,and ATM.TNFSF6 and CYP1A1 were detected by polymerase chain reaction(PCR)to verify the expression at different time points,and the results showed that TNFSF6 was up-regulated and CYP1A1 was down-regulated as the total expression.GO and kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis suggested that the oxidative stress genes mediate MIRI via various ways such as unfolded protein response(UPR)and apoptosis.CONCLUSIONS:WBCs,especially neutrophils,were the critical cells that mediating reperfusion injury.MIRI was regulated by various genes,including oxidative metabolic stress,heat shock,DNA damage and repair,and apoptosis-related genes.The underlying pathway may be associated with UPR and apoptosis,which may be the novel therapeutic target.
文摘BACKGROUND:Hyperbaric oxygen(HBO)is an effective adjuvant therapy for ischemiareperfusion(I/R)injury of the brain,small intestine and testis in addition to crushing injury.Studies have shown that HBO increases the activity of villi of the ileum 30 minutes after I/R injury.The present study aimed to observe the effect of HBO on apoptosis of epithelial cells in the small intestine during different periods of I/R and to elucidate the potential mechanisms.METHODS:Rats were subjected to 60-minute ischemia by clamping the superior mesenteric artery and 60-minute reperfusion by removal of clamping.The rats were randomly divided into four groups:I/R group,HBO precondition or HBO treatment before ischemia(HBO-P),HBO treatment during ischemia period(HBO-I),and HBO treatment during reperfusion(HBO-R).After 60-minute reperfusion,samples of the small intestine were prepared to measure the level of ATP by using the colorimetric method and immunochemical expression of caspase-3.The levels of TNF-αin intestinal tissue were measured using the enzyme-linked immunosorbent assay method(Elisa).RESULTS:TNF-αlevels were significantly lower in the HBO-I group than in the HBO-P(P<0.05),HBO-R and I/R groups;there was no significant difference between the HBO-R and I/R groups(P>0.05).The expression of caspas-3 was significantly lower in the HBO-I group than in the HBO-P group(P<0.05);it was also significantly lower in the HBO-P group than in the I/R and HBO-R groups(P<0.05).ATP level was significantly lower in the HBO-I group than in the HBO-P group(P<0.05),and also it was significantly lower in the HBO-P group than in the I/R and HBO-R groups(P<0.05).CONCLUSIONS:There is an association between HBO,small intestinal I/R injury,and mucosa apoptosis.HBO maintains ATP and aerobic metabolism,inhibites TNF-αproduction,and thus prevents intestinal mucosa from apoptosis.Best results can be obtained when HBO is administered to patients in the period of ischemia,and no side effects are produced when HBO is given during the Period of Reperfusion.
基金Supported by Peking Union Medical College Youth Research Funds(3332016010)Peking Union Medical College Graduate Studen Innovation Fund(2015-1002-02-09)
文摘Objective Oxidative stress （OS） plays a crucial role in ischemic stroke. Grape seed procyanidin extract （GSPE） was reported to be a critical regulator of OS. We hypothesized that GSPE might also be protective in ischemia-reperfusion brain injury. This study aimed to explore whether GSPE administration can protect mice from ischemia-reperfusion brain injury. Methods Transient middle cerebral artery occlusion （MCAO） was conducted followed by reperfusion for 24 hours to make ischemia-reperfusion brain injury in mice that received GSPE （MCAOG, n=60） or normal saline （MCAONS, n=60）. Sham-operated mice （GSPE group and normal saline group） were set as controls. The neurological severity score （NSS） was used to evaluate neural function impairment 1 hour, 24 hour, 3 days and 7 days after MCAO. Mice underwent brain T2WI imaging with a 3T animal MRI scanner 24 hours after reperfusion, and the stroke volume of brains were calculated according to abnormal signal intensity. Immunohistopathological analysis of brain tissues at 24 h after reperfusion was performed for neuronal nuclear antigen （NeuN）, CD34, Bcl-2, and Bax. Glutathione peroxidation （GSH-Px） activity and the level of malonaldehyde （MDA） of brain tissue were also examined. The above indexes were compared among the groups statistically.Results Significant functional improvement was observed 24 hours after MCAO in MCAOG group compared to MCAONS group （P〈0.05）. MCAOG group had smaller cerebral stroke volume （22.46 ± 11.45 mm3 vs. 47.84±9.06 mm3, P〈0.05） than MCAONS group 24 hours after MCAO. More mature NeuN-immunoreactive neurons and more CD34-positive cells in peri-infarct zones were observed in brain tissue of MCAOG mice 24 h after MCAO than that of MCAONS mice （both P〈0.05）. MCAONS mice had significantly higher number of Bax-positive cells in brain tissue than MCAOG （P〈0.05）. The mean MDA level was significantly lower （P〈0.05） and the GSH-Px activity was significantly higher （P〈0.05） in brains of MCAOG mice compared to those of MCAONS mice. Conclusion GSPE administration protects mice from ischemia-reperfusion brain injury through attenuating oxidative stress and apoptosis, promoting angiogenesis, and activating antioxidant enzyme GSH-Px. GSPE may represent a new therapeutical direction for the treatment of ischemia-reperfusion brain injury.
基金Fund supported by National Science Foundation of China (NSFC) 81503491,81374053, 81630105.
文摘Objective To study the protective effect of agrimony extracts from different extracting methods on cerebral ischemia-reperfusion injury in rats, in order to optimize the extraction scheme of agrimony.Methods Male rats were randomly assigned into seven groups: 1. Sham-operated group, 2. Untreated MCAO group (MCAO), 3. Petroleum ether extract of Agrimonia pilosa treated MCAO group (PEA), 4. Ethyl acetate extract of Agrimonia pilosa treated MCAO group (EAEA), 5. Ethanol extract of Agrimonia pilosa treated MCAO group (EEA), 6. Water extract of Agrimonia pilosa treated MCAO group (WEA), 7. Nimodipine treated MCAO group (NP). Intragastrical drug administration (i.g) was performed at 0 and 6 hours after MCAO.Neurological function tests were performed after reperfusion for 24 hours, then the brain was removed for the evaluations of the cerebral infarction volume (percentage of total brain volume) by immunohistochemistry,histological changes (hematoxylin-eosin staining), Na+/K+-ATPase, Ca2+-ATPase (modified method of Svoboda and Mosinger), mRNA expression of Tumor suppressor gene (P53) and hot shock protein (HSP70)(quantitative real-time PCR).Results The neurological function of MCAO group had significantly higher scores than the sham group (P<0.01). The WEA group showed a significantly lower neurological score than the MCAO group (P<0.05),indicating the protective effect of WEA on neurological deficits. The mean infarction volumes of WEA (13.5±6.6%, F=4.75, P<0.01), EEA (19.90±6.90%, F=5.23, P<0.01), PEA (20.40±5.30%, F=4.68,P<0.01) and EAEA (22.50±10.50%, F=6.25, P<0.05) group were all significantly smaller than that of MCAO group (29.40±6.50%). HE staining demonstrated that, compared to the treated groups, the infarcted cerebral tissue of MCAO group had more swelling neural cells, lighter stained nucleus, fewer and irregularly distributed neurons. The activity of Na+/K+-ATPase and Ca2+-ATPase reduced in the MCAO group (3.67±0.48 U/mg,1.28±0.26 U/mg, respectively), and were significantly higher in WEA group (7.56±0.85 U/mg, F=12.65,P=0.010; 3.59±0.22 U/mg, F=8.32, P=0.041, respectively). The MCAO group showed significantly elevated P53 and HSP70 mRNA expressions compared to the sham group (P<0.01, P<0.05). P53 mRNA expressions in Agrimony extracts treated groups were significantly lower than that of the MCAO group (all P<0.01), with the WEA group showing the greatest difference from MCAO group. The HSP70 mRNA level of the treated groups were not significantly different from that of the MCAO group.Conclusions Treatment using water extracts of agrimony can promote the best functional and metabolic recovery for rat model of cerebral ischemia-reperfusion injury, which maybe relate with the upregulation of energy metabolism in nerve cells after MCAO.
基金Supported by Shaanxi Provincial Scientific and Technological Research Projects (2008K13-02)
文摘Objective： To investigate whether remifentanil induced cardioprotecting effect is associated with expression of toll-like receptor 4 （TLR4）, nuclear factor rB （NF-r.B） and serum interleukin -6 （IL-6）. Methods： Fifty rabbits were randomly divided into 5 groups （n=10） according to the treatment： sham operation group （group A）, ischemla-reperfusion group （group B）, low-dose remifentanil group （group C）, mediate-dose remifentanil group （group D）, and high-dose remlfentanil group （group E） Myocardial TLR4 mRNA levels, NF-r.B protein expression and serum levels of IL-6 were observed in 120 min after reperfusion. Results： The myocardial expressions of TLR4 mRNA, NF-rd3 protein and IL-6 level in sera of groups B, C, D and E were elevated compared with group A. However, remifentanil significantly reduced the levels of TLR4 mRNA, NF- r.B protein expression and serum IL-6 in groups C, D and E compared with group B. There were remarkable differences between the groups （P〈O.O1）. Conclusion： Intravenous remifentanil has protective effect against rabbit myocardial ischemia/reperfusion injury. This effect may be associated with TLR4, NF-r.B expressions on myocytes and serum level of IL-6 in a dose-dependent manner
文摘The effect of myocardium being subjected to 60 min ischemia and 60 min reperfusion incat cardiopulmonary bypass on level of lipid peroxides(LPO),function of myocardial mitochon-dria and activity of superoxides dismutase(SOD)was studied. Myocardial mitochondrial functionwas depressed slightly 60 rain after ischemia but significantly 60 min after reperfusion.Increasedlipid peroxides content and decreased activity of SOD were observed at 60 rain after ischemia.Af-ter reperfusion,the activity of SOD continued decreasing,and LPO elevated still further.Theseresults support the hypothesis that free radicals may contribute to myocardial reperfusion injury.
文摘It is known that reperfusion injury occurs after reperfusion with normal blood in ischemic myocardium. Using the cat cardiopulmonary bypass model, this study documented that myocardial mitochondrial function was sigmficantly depressed 60min after reperfusion, but was only slightly depressed in the controlled reperfusion group. Significantly increased MDA content and decreased activity of SOD was observed 60 min after reperfusion, whereas in the controlled reperfusion group, the MDA content was low and the activity of SOD was protected. These results indicate that controlled reperfusion with warm blood cardioplegia containing mannitol after ischemia provides benefit in avoiding myocardial mitochondrial reperfusion injury by preventing or reducing a potentially harmful component of reperfusion.
文摘objective: To investigate the changes of spinal cord blood flow (SCBF) after the ischemia and reperfusion injury of the spinal cord and its relation with pathological damages. Methods: Twenty adult Japanese big-ear white rabbits equally randomized into the control group, 30-min-ischemic group, 60-min-is chemic group and 90-min-ischemic group. All the rabbits in the latter 3 groups were inflicted with the is chemia and reperfusion injury of the spinal cord through selective occlusion of the lumbar artery. SCBF was measured with the hydrogen clearance method and the pathological changes of the injured spinal cord were observed with Nissl’s staining. Results: SCBF during ischemia was 0 ml/100 g/min. During reperfusion, it was recovered to different levels. However, it was still decreased as compared with that before ischemia and that in the control group. The pathological changes of the gray matter were the most significant. The severi ty of the pathological changes decreased in the order from 90-min-ischemic group, 6O-min-ischemic group to 30-min ischemic group. Conclusion: Reversible injury occurs in rabbits after ischemia for 30 min, irreversible injury in those after ischemia for 90 min and partially reversible injury in those after ischemia for 60 min.
文摘Objective To elucidate whether endoxin is one of important factors involved in myocardial ischemia reperfusion (MIR) injury, the change of myocardial endoxin level was determined in rats with MIR injury model and the effects of anti-digoxin antiserum (ADA), an endoxin specific antagonist, on MIR injury were studied. Methods MIR injury model was obtained by ligating left anterior descending coronary artery 30 min followed by 45 min reperfusion. Sprauge Dawley rats were randomly divided into six groups of 10 rats, each. Sham group, MIR group, normal saline group, ADA 9, 18 and 36 mg/kg. ECG was continuously recorded. After reperfusion left ventricular myocardium samples of ischemic area were processed immediately. Myocardial endoxin level, Na++/K++-ATPase, Ca+{2+}-ATPase, Mg+{2+}-ATPase activities, and intramitochondrial Ca+{2+} content were measured. Results Myocardial endoxin level was significantly increased; Na++/K++-ATPase, Ca+{2+}- ATPase , and Mg+{2+}-ATPase activities were remarkably decreased; intramitochondrial Ca+{2+} content was remarkably raised; ST segments of ECG were significantly elevated and occurrence and scores of ventricular arrhythmias were significantly increased in early stage of reperfusion in rats with MIR. In all groups with ADA, myocardial endoxin level was remarkably decreased; Na++/K++-ATPase, Ca+{2+}-ATPase and Mg+{2+}-ATPase activities were drastically increased; intramitochondrial Ca+{2+} content was declined; ST segments and ventricular arrhythmias were improved. Conclusion Myocardial endoxin level was increased in MIR, which implies that the elevated endoxin may be one of major factors inducing MIR injury. This postulate is supported by the observation that ADA has protective and therapeutic effects against MIR injury probably by antagonizing the action of endoxin. The underlying mechanism may be ascribed to restoration of energy metabolism, and attenuation of intracellular Ca+{2+} overload.
文摘The aim of this study was to determine the time course of changes in extracellular fluid (ECF) concentrations of purines, amino acids, monoamines, and their metabolites in the striatum of rats during ischemia and reperfusion, using intracerebral microdialysis as the sampling technique. In rats subjected to 20 min forebrain ischemia by four-vessel occlusion, the concentrations of adenosine (Ade), inosine (Ino) and hypoxanthine (Hyp) were found to rise markedly. These changes were accompanied by dramatically elevated levels of aspartate (Asp), glutamate (Glu), taurine (Tau), γ-aminobutyric acid (GABA), dopamine (DA) and norepinephrine (NE), all of which gradually returned to baseline following reperfusion. Concomitantly, the levels of metabolite 3, 4-dihydroxyphenylacetic acid (DOPAC) . homovanillic acid (HVA), 5-hydroxyindole-3-acetic acid (5-HIAA) and xanthine (Xan) decreased during ischemia and gradually recovered 60～ 90 min after reperfusion. It was concluded that during global brain ischemia, the ECF is flooded with both potentially harmful (e. g. Asp, Glu, DA) and protective (e. g. Tau, GABA, Ade) agents.
文摘Objective: To study the changes of oxygen free radical, expression of apoptotic gene, ultrastructure of myocardial cell and second injury of the heart following the intestinal ischemia and reperfusion. Methods: Making the models of ischemia and reperfusion by clamping superior mesenteric artery, the concentration of NO and SOD in the blood was examined before clamping the artery and reperfusion for 0, 30, 60 min, 1, 3, and 7 d. The expression of Bax, Bal-2, and p53 in myocardial cell was studied by means of immunohistochemical SP method and the microstructure damage was observed under electron microscopy. Results: After clamping the superior mesenteric artery and reperfusion the concentration of NO increased continuously and reached a peak for reperfusion 7 d (P<0.01) but that of SOD decreased from 30 min to 7 d. The expression of Bax, p53 and Bcl-2 also increased obviously especially for reperfusion 30 min and 7 d following ischemia and reperfusion. After reperfusion for 30 min the positive cell rate of Bax, p53 and Bcl-2 was 53.6%, 45.9% and 67.9%, for reperfusion 7 d it was 52.4%, 43.4% and 31.9% respectively, but the positive cell rate of Bax and p53 was higher than that of Bcl-2. The result of electron microscopy observation showed mfofiliments breaked, dissolved and chromatin condensed. Conclusion: Intestinal ischemia and reperfusion of rat can induced the changes of oxygen free radical and the expression of apoptotic gene and second injury of myocardial cells.
基金supported by grants from the National Nature Science Foundation of China(81201444 and 81101401)
文摘BACKGROUND:Recent studies have showed that S100A8 has been implicated in the pathobiology of inflammatory disorders,and that cerebral ischemia reperfusion(l/R) rapidly activates inflammation responses via Toll-like receptor 4(TLR4).This study aimed to explore the expression of S100A8 and the relationship between S100A8 and TLR4 in focal cerebral ischemia reperfusion injury.METHODS:C3H/HeJ mice(n=30) and C3H/HeN mice(n=30) were divided randomly into a C3H/HeJ model group(n=18),a C3H/HeJ control group(n=12),a C3H/HeN model group(n=18),and a C3H/HeN control group(n=12).Middle cerebral artery l/R model in mice was produced using a thread embolism method.The brains of the mice were collected after ischemia for 1 hour and reperfusion for 12 hours.Stroke outcome was evaluated by determination of infarct volume and assessment of neurological impairment scores.Brain injury after cerebral l/R was observed by an optical microscope after TTC and HE dyeing.The immunofluorescence technique and real time PCR were used to test the expression level of S100A8 in brain damage.RESULTS:Compared with C3H/HeN mice,TLR4-deficient mice(C3H/HeJ) had lower infarct volumes and better outcomes in neurological tests.The levels of S100A8 increased sharply in the brains of mice after l/R injury.In addition,mice that lacked TLR4(C3H/HeJ) had lower expression of l/R-induced S100A8 than C3H/HeN mice in the model group,indicating that a close relationship might exist between the levels of S100A8 and TLR4.CONCLUSION:S100A8 interaction with TLR4 might be involved in brain damage and in inflammation triggered by l/R injury.
文摘Objective To study the protecting effects and mechanism of betaine hydrochloride on hepatic ischemia-reperfusion injury in rats.Methods Fourty SD rats were randomly divided into 5 groups(8 animals in each group):sham-operated control group(A),hepatic ischemia-reperfusion group(B),200 mg·kg-1 400 mg·kg-1 800 mg·kg-1 betaine hydrochloride+hepatic ischemia-reperfusion group(C、D、E).betaine hydrochloride was administered to animals byoral route in group C、D、E for 7 days before ischemia.A、B group was administered with NS.Made the animal model of part hepatic ischemia-reperfusion.Serum alanine aminotransferase(ALT),aspartate aminotransferase(AST)levels in the blood and themalondialdehyde(MDA),superoxide dismutase(SOD),protein content in hepatic tissue were determined after the liver had been reperfused for 24 hours;the hepatic tissue was examined under lightmicroscope and the cell apoptosis was demonstrated with flow cytometry.Results ALT,AST,MDA increased and SOD decreased significantly in B group when compared those in the A group(P<0.05),Hepatic apoptosis was significantly increased;ALT,AST,MDA decreased and SOD increased significantly in betaine hydrochloride 200 mg·kg-1(C)group when compared those in the B group(P<0.05).Hepatic apoptosis was significantly lower,The histologic changes of the liver tissue under lightmicroscope in the C group was more easer than in the I/R group(B).Conclusions Betaine hydrochloride has the ability to scavenge oxygen free radical(OFR),reduce lipid peroxidation and inhibition of apoptosis.So it can protect the rats liver damaged by ischemia-reperfusion.
基金supported in part by grants from the National Key Program for Fundamental Research and Development(973 Project,Grant No.G1999054203)National Natural Science Outstanding Youth Foundation(Grant No.30125020)the National Natural Science Foundation(Grant No.39870286,30200293)of China.
文摘Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whether pretreatment with monoclonal antibody against TNF-α (TNF-α MoAb) would affect the release of D(-)-lactate after local gut ischemia followed by reperfusion. Methods Anesthetized Sprague-Dawley rats underwent superior mesenteric artery occlusion for 75 min followed by reperfusion for 6 hr. The rats were treated intravenously with either TNF-α MoAb (20 mg/kg) or albumin (20 mg/kg) 30 min prior to the onset of ischemia. Plasma D(-)-lactate levels were measured in both the portal and systemic blood by an enzymatic spectrophotometric assay. Intestinal TNF-αmRNA expression as well as protein levels were also measured at various intervals. In addition, a postmortem examination was performed together with a macropathological evaluation based on a four-grade scoring system.Results Intestinal ischemia resulted in a significant elevation in D(-)-lactate levels in the portal vein blood in both the control and treatment groups ( P ＜0.05). However, animals pretreated with TNF-α MoAb at 6 hr after reperfusion showed significant attenuation of an increase in both portal and systemic D(-)-lactate levels when compared with those only receiving albumin (P ＜ 0.05). In the control animals, a remarkable rise in intestinal TNF-α level was measured at 0.5 hr after clamp release ( P ＜ 0.01); however, prophylactic treatment with TNF-α MoAb completely annulled the increase of local TNF-α levels seen in the control animals. Similarly, after anti-TNF-α MoAb administration, intestinal TNF-α mRNA expression was markedly inhibited, which showed significant differences when compared with the control group at 0.5 hr, 2 hr and 6 hr after the release of occlusion ( P ＜ 0.05-0.01 ). In addition, the pathological examination showed marked intestinal lesions that formed during ischemia, which were much worse upon reperfusion,particularly at the 6 hr time point. These acute injuries were obviously attenuated in animals receiving TNF-α MoAb.Conclusions It appeared that acute intestinal ischemia was associated with failure of the mucosal barrier, resulting in increased plasma D(-)-lactate levels in both portal and systemic blood. These results suggest that TNF-α appears to be involved in the development of local damage associated with intestinal ischemic injury. Moreover, prophylactic treatment with TNF-α MoAb exerts preventive effects on ischemia/ reperfusion-induced circulating D (-)-lactate elevation and gut injury. ( J Geriatr Cardiol 2004;1(2):119-124. )
基金supported by grants from the National Science Foundation of China(30740080)Dean fund of the General Hospital of Jinan Military Command(2011Q08)
文摘BACKGROUND: Rapid and complete reperfusion has been widely adopted in the treatment of patients with acute myocardial infarction(AMI), but this process sometimes can cause severe reperfusion injury. This study aimed to investigate different patterns of post-conditioning in acute myocardial ischemia-reperfusion injury, and to detect the role of mitogen activated protein kinase(MAPK) during the injury.METHODS: Rats were randomly divided into five groups: sham group, reperfusion injury(R/I) group, gradually decreased reperfusion group(GDR group, 30/10-25/15-15/25-10/30 seconds of reperfusion/ischemia), equal reperfusion group(ER group, 20/20 seconds reperfusion/ischemia, 4 cycles), and gradually increased reperfusion group(GIR group, 10/30-15/25-25/15-30/10 seconds of reperfusion/ischemia). Acute myocardial infarction and ischemic post-conditioning models were established in the rats. Six hours after reperfusion, 3 rats from each group were sacrificed and myocardial tissues were taken to measure the expressions of phosphorylation of extracellular signalregulated protein kinase(P-ERK), phosphorylated c-Jun N-terminal kinase(P-JNK), mitogen-activated protein kinase p38(p38 MAPK), tumor necrosis factor-α(TNF-α), caspases-8 in the myocardial tissue, and cytochrome c in the cytosol using Western blot. Hemodynamics was measured at 24 hours after reperfusion, the blood was drawn for the determination of cardiac enzymes, and the heart tissue was collected for the measurement of apoptosis using TUNEL. One-way analysis of variance and the Q test were employed to determine differences in individual variables between the 5 groups.RESULTS: Three post-conditioning patterns were found to provide cardioprotection(P<0.05) compared with R/I without postconditioning. GIR provided the best cardioprotection effect, followed by ER and then GDR. Apoptotic index and serum marker levels were reduced more signifi cantly in GIR than in ER(P<0.05). The enhanced cardioprotection provided by GIR was accompanied with significantly increased levels of P-ERK 1/2(1.82±0.22 vs. 1.54±0.32, P<0.05), and lower levels of p-JNK, p38 MAPK, TNF-α, caspase-8, caspase-9 and cytochrome in the cytoplasm(P<0.05), compared with ER. The infarct size was smaller in the GIR group than in the ER group, but this difference was not significant(16.30%±5.22% vs. 20.57%±6.32%, P<0.05). All the measured variables were improved more signifi cantly in the GIR group than in the GDR group(P<0.05).CONCLUSION: Gradually increased reperfusion in post-conditioning could attenuate reperfusion injury more significantly than routine method, thereby the MAPK pathway plays an important role in this process.
