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ObjectiveTo investigate the effect of xenon post-conditioning on autophagy after spinal cord ischemia/reperfusion injury (SCIRI) in rats and its relationship with protein kinase B (Akt) signaling pathway. MethodsA total of 30 male rats were randomized into sham-operated group (sham group), spinal cord ischemia/reperfusion injury group (I/R group) and I/R + xenon post-conditioning group (Xe group), with ten rats in each group. In the latter two groups, SCIRI was induced by clamping the abdominal aorta for 85 minutes followed by reperfusion for four hours. Xe group inhaled xenon and oxygen (1∶1) for one hour at one hour after initiation of reperfusion, while the other groups inhaled nitrogen and oxygen (1∶1) for one hour. After the reperfusion, they were assessed with Basso-Beattie-Bresnahan (BBB) scale and slanting board test. And then, their spinal cords of L3-5 were obtained. Nissl staining was used to count the number of normal neurons. Western blotting was used to detect the protein expression of Akt, p-Akt, p62, Beclin 1, microtubule-associated protein 1 light chain 3 (LC3) Ⅰ, LC3 Ⅱ. The mRNA expression of Beclin 1, p62 and LC3 Ⅱ in the spinal cord was measured with reverse transcription real-time quantitative polymerase chain reaction. ResultsCompared with the sham group, the BBB score and the maximum inclination of the slanting board test decreased, the count of normal neurons decreased, the protein expression of p62 and the p-Akt/Akt ratio decreased (P < 0.01), the protein and mRNA expression of Beclin 1 and LC3 Ⅱ, and the LC3 Ⅱ/LC3 Ⅰ ratio increased, the p62 mRNA expression decreased (P < 0.01) in the I/R group. Compared with the I/R group, the BBB score and the maximum inclination of the slanting board test increased, the count of normal neurons increased, the protein expression of p-Akt and p62 increased, the p-Akt/Akt ratio increased, the protein and mRNA expression of Beclin 1, LC3 Ⅱ and LC3 Ⅱ/LC3 Ⅰ ratio decreased, and the mRNA expression of p62 increased (P < 0.01) in Xe group. ConclusionXenon post-conditioning may relieve SCIRI in rats, which is related to activating Akt signaling pathway to inhibit autophagy.
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Mitochondria, as the key passway of neuronal apoptosis after ischemia, is closely related to cerebral ischemia-reperfusion injury. Remote ischemic post-conditioning can alleviate cerebral ischemia-reperfusion injury, and its mechanism is related to alleviating mitochondrial injury and improving its dysfunction. In this paper, cytochrome C/caspase, mitophagy, mitochondrial ATP-sensitive K+ channel and mitochondrial permeability transitionpore were reviewed.
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BACKGROUND: Curcumin pre-conditioning can alleviate liver Injury induced by limb Ischemia/reperfusion (l/R), but whether curcumin post-conditioning has protective effect against liver cold l/R Injury and its mechanism are still poorly studied. OBJECTIVE: To Investigate the effects of curcumin post-conditioning on hepatocyte apoptosis in rats with liver cold l/R Injury in rats. METHODS: Eighty adult male Sprague-Dawley rats were randomly divided Into four groups (n-20 per group) by using a random number table: Sham group, l/R group, curcumin post-conditioning group (l/R+Cur group), and dexamethasone group (l/R+Dex group). The liver blood flow was completely blocked. Then the splenic vein and the adrenal vein were used as the inflow and outflow tracts to inject 0 °C compound Ringer lactate solution followed by cold perfusion for 30 minutes. After stopping cold perfusion, the proximal splenic vein and the right adrenal vein were ligated to remove the spleen, and then the blood flow In the liver restored. The cold l/R model was successfully established. After 30 minutes of cold ischemia, 60 mg/kg curcumin was injected Into the rat tail vein In the l/R+Cur group, 0.5 mg/kg dexamethasone was injected Into the rat tail vein In the l/R+Dex group, and the same amount of saline was Injected in the other groups. Blood sample was taken from the carotid artery at 6 hours after reperfusion. Serum levels of aspartate aminotransferase and alanine transferase were detected. Then the rats were sacrificed to detect malondlaldehyde level In liver tissue, observe liver pathological changes by hematoxylin-eosin staining, measure hepatocyte apoptosis Index by Hoechst 33258 staining, detect expression of Bcl-2 and Bax protein by western blot, expression of caspase-9 mRNA by RT-PCR, and levels of tumor necrosis factor-a and interleukin-1 ß by ELISA. RESULTS AND CONCLUSION: Compared with the sham group, aspartate aminotransferase, alanine transferase, malondialdehyde levels and apoptosis Index in the l/R group increased significantly (P 0.05). In a word, curcumin-post conditioning can alleviate liver injury induced by cold l/R in rats. Its mechanism may be related to down-regulation of Bcl-2/Вах ratio, inhibition of caspase-9 mRNA expression, and reduction of the release of tumor necrosis factor-a and interleukin-1 ß, therefore playing an antl-apoptotic role in liver protection.
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Aim To investigate the effects of isoflu-rane on angiogenesis in rats with cerebral ischemia/reperfusion and the possible mechanism. Methods Forty healthy adult male Sprague-Dawley rats were randomly divided into sham operation group (Sham group) , ischemia-reperfusion group (I/R group) , isoflurane post-treatment group (ISO group) and isoflurane post-treatment + Smad3 specific inhibitor SIS3 HC1 group (ISO + SIS3 group). Rat middle cerebral artery occlusion model (MCAO) was established by suture method. After 24 h, Zea-Longa method was used to evaluate the neurological deficit of rats. HE staining was used to evaluate the pathological damage of brain tissues. Nissl staining was used to evaluate the surviving neurons in ischemic brain tissues. TUNEL staining was employed to assess the apoptosis of brain tissues. Immunofluorescence was applied to evaluate the expression levels of VEGF and CD34. Western blot analysis was used to detect the expression levels of p-Smad3, Smad3 , VEGF and CD34. Results Isoflurane significantly reduced the neurobehavioral score of rats, reduced the pathological damage of brain tissues, increased the number of normal neurons in the ischemic brain tissues, reduced the apoptotic cells in injured brain tissues, and enhanced the expression levels of p-Smad3, VEGF and CD34. Smad3 inhibitor re-versed the brain protective effect of isoflurane, aggravated cerebral ischemia-reperfusion injury, and inhibited the protein expression levels of p-Smd3 , VEGF and CD34. Conclusions Isoflurane can improve cerebral ischemia/reperfusion injury in rats, and its protective mechanism is related to activation of Smad signaling pathway, promotion of VEGF and CD34 protein expression , and promotion of angiogenesis.
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OBJECTIVE@#To investigate the recovery of protective effects of exogenous hydrogen sulfide (HS) on hypoxia post-conditioning in aged H9C2 cells and its mechanism.@*METHODS@#H9C2 cells (cardiomyocytes line) were treated with 30 μmol/L hydrogen peroxide (HO) for 2 hours, then cultured for 3 days in order to induce cellular aging. Aged H9C2 cells were randomly divided into 5 groups (=8):Control group (Control), hypoxia/reoxygenation group (H/R), H/R + NaHS group, hypoxia post-conditioning (PC) group, PC+NaHS group. H/R model:the cells were exposed to hypoxic culture medium (serum and sugar free medium, pH=6.8) for 3 hours and then cultured at normal condition for 6 hours. PC model:at the end of hypoxia for 3 hours, the cells were exposed to normoxic culture solution for 5 minutes, then the cells were placed in hypoxic solution for 5 minutes, the cycle above-mentioned was repeated 3 times and followed by reoxygenation for 6 hours. Advanced glycation end products (AGEs) content and caspase-3 activity were detected by ELISA. The cell viability was observed by cell counting kit-8 (CCK-8). The reactive oxygen species (ROS) levels were analyzed using 2, 7-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. The apoptotic rate was determined through Hoechst 33342 staining. The mRNA levels of relative gene expression were detected by real-time PCR.@*RESULTS@#Thirty μmol/L HO induced H9C2 cell senescence while did not lead to apoptosis. Compared with control group, cell viability was decreased, the apoptotic rate、levels of ROS and the mRNA of caspase-3, caspase-9 and Bcl-2 were increased in H/R and PC groups (<0.01). There were no differences in the above indexes between PC group and H/R group. Supplementation of NaHS increased cell viability and decreased apoptotic rate and oxidative stress. The effects of PC + NaHS on the above indexes were better than those of H/R+NaHS group.@*CONCLUSIONS@#Exogenous HS can restore the protective effect of PC on the aged H9C2 cells, and its mechanism is related to the inhibition of oxidative stress and apoptosis.
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Humans , Apoptosis , Cell Hypoxia , Cell Survival , Hydrogen Peroxide , Myocytes, Cardiac , Reactive Oxygen SpeciesABSTRACT
The aim of this paper was to study the effect of total flavones of Clematis filamentosa Dunn(TFCD) post-conditioning against myocardial ischemia-reperfusion injury (MIRI) and the role of PI3K/Akt-eNOS signaling pathway. Forty male SD rats were divided randomly into five groups: Sham group, model group (I/R), TFCD post-conditioning group (TFCD), TFCD post-condition-ing+LY294002 (a PI3K/Akt signaling pathway inhibitor) group (TFCD+LY), and LY294002 group (LY). At the end of reperfusion, hemodynamic parameters were recorded, morphology changes of myocardial tissue were evaluated by using HE staining, and myocardial infarct size were observed, blood samples were obtained to determine plasma activation of lactate dehydrogenase (LDH), creatine kinase (CK) nitric oxide (NO), endothelial nitric oxide synthase (eNOS), superoxide dismutase (SOD), maleic dialdehyde (MDA) and glutathione peroxidase (GSH-Px). The expressions of Akt, p-Akt, eNOS and p-eNOS proteins were assessed by using Western blot, and eNOS and inducible nitric oxide synthase (iNOS) mRNA was measured by RT-PCR. The results showed that, compared with the model group, TFCD post-conditioning remarkably improved hemodynamics function and myocardial structure, reduced myocardial infarct size and enhanced the contents of NO, eNOS, SOD and GSH-Px, and decreased the contents of LDH, CK and MDA, increased the levels of phosphorylation of Akt and eNOS protein expression, eNOS and iNOS mRNA expression significantly(P＜0.05 or P＜0.01). These effects were inhibited by LY294002, a blocker of PI3K/Akt signaling pathway. The above experiments indicated that TFCD post-conditioning could significantly reduce MIRI in rats, the mechanism of which may be associated with increasing antioxidation, scavenging oxygen free radicals, regulating NO generation and activating PI3K/Akt-eNOS signaling pathway.
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Animals , Male , Rats , Clematis , Flavones , Myocardial Reperfusion Injury , Nitric Oxide Synthase Type III , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Rats, Sprague-Dawley , Signal TransductionABSTRACT
Objective To investigate the effectiveness of combination treatment of thrombus aspiration and ischemic post-condition on patients with acute ST elevated myocardial infarction(SETMI) undergoing primary percutaneous coronary intervention. Methods A total of 234 patients were randomly divided into two groups: one group received routine treatment (control group, n=111); while another group received the combination treatment of thrombus aspiration and ischemic post-conditioning (treatment group, n=123). The baseline data, coronary lesion, information of percutaneous coronary intervention, data of reperfusion and in-hospital clinical prognosis of the two groups were evaluated. Results The baseline data of the two groups are comparable except TG level was higher in treatment group. Compared with the control group, the peak value of cardiac enzyme was lower while the rate of immediate ST resolution to baseline was higher with less MACE during hospitalization in the treatment group. Other data were all comparable between the two groups. Conclusions The combination of thrombus aspiration and ischemic post-conditioning during primary PCI in patients with acute myocardial infarction can restore cardiac perfusion and reduce MACE during hospitalization.
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Objective To observe the effect of remote post-ischemic conditioning(RPIOC)on the cerebral blood flow,neural function and prognosis of patients with acute cerebral infarction and the risk factors for short-term prognosis.Methods 133 patients with acute cerebral infarction in the Second Hospital of Beijing from January 2016 to December 2017 were selected,and randomly divided into the RIPOC group(66 cases,with RPIOC)and the control group(67 cases,without RIPOC).In the first day after hospital,patients in the RIPOC group were given RIPOC,which was tightening the left aim with a tonometer bandage for 5 minutes per time and 2 times a day at an interval of 5 minutes.All patients were provided routine treatment.All patients' cerebral blood flow,neural function and survival data were recorded.Recovery was assessed by modified Rankin Scale(mRS)180 d after stroke.Logistic regression was used to evaluate the risk factors for prognosis.Results Of the 133 patients enrolled,there were 67 males.The mean age was (73.1 ± 10.1)year.Basic clinical characteristics,neural function and cerebral blood flow were similar between groups(P＞0.05).After 10 d treatment,cerebral blood flow and neural function was significantly increased (P＜0.05)in the RIPOC group.After 180 d follow up,the RIPOC group had significantly higher rate of adverse cerebrovascular events(P＜0.05).Logistic regression analyses demonstrated that advanced age(P =0.003),hypertension(P =0.03)and high NIHSS score(P =0.005)were all risk factors for prognosis.Conclusions RIPOC can enhance the cerebral blood flow,activities of daily living,limb function and prognosis.However,it does not reduce the risk of mortality.Advanced age,hypertension and high NIHSS score are risk factors for short-term prognosis.
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Abstract Purpose: To investigate whether modulating GSK-3β could attenuate myocardial ischemia reperfusion injury (MIRI) induced acute lung injury (ALI) and analyze the underlying mechanism. Methods: Male SD rats were subjected to MIRI with or without myocardial ischemic post-conditioning in the presence or absence of GSK-3β inhibitor. GSK-3β inhibitor was injected peritoneally 10min before MIRI. Lung W/D weight ratio, MPO, PMNs, histopathological changes, TUNEL, Bax, Bcl-2, IL-6, IL-8, IL-10, GSK-3β, and caspase-3 were evaluated in the lung tissues of all rats. Results: After MIRI, lung injury was significantly increased manifested as significant morphological changes and increased leukocytes in the interstitial capillaries, Lung W/D ratio, MPO, and PMN in BALF, which was associated with enhanced inflammation evidenced by increased expressions of IL-6, IL-8 and reduced expression of IL-10. MIRI significantly increased cell apoptosis in the lung as increased levels of apoptotosis, Bax, cleaved caspase-3, and reduced expression of Bcl-2 was observed, which was concomitant with reduced p-GSK-3β. All these changes were reversed/prevented by ischemic post-conditioning, while these beneficial effects of ischemic post-conditioning were abolished by GSK-3β inhibition. Conclusion: Myocardial ischemia reperfusion injury induces acute lung injury by induction of inflammation and cell apoptosis. Ischemic post-conditioning protects the lung from ALI following MIRI by increasing p-GSK-3β.
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Animals , Male , Myocardial Reperfusion Injury/prevention & control , Protective Agents/metabolism , Acute Lung Injury/prevention & control , Ischemic Postconditioning/methods , Glycogen Synthase Kinase 3 beta/metabolism , Random Allocation , Down-Regulation , Interleukins/metabolism , Rats, Sprague-Dawley , Apoptosis/drug effects , Peroxidase/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Protective Agents/pharmacology , In Situ Nick-End Labeling , Models, Animal , Enzyme Activation , bcl-2-Associated X Protein/metabolism , Caspase 3/metabolism , Acute Lung Injury/enzymology , Glycogen Synthase Kinase 3 beta/antagonists & inhibitors , Glycogen Synthase Kinase 3 beta/pharmacology , Inflammation/metabolism , Myocardial Infarction/pathology , Neutrophils/enzymologyABSTRACT
ABSTRACT Background: Mesenteric ischemia is a challenging diagnosis. Delay in diagnosis can lead to extent bowel necrosis and poor outcomes. Ischemia and reperfusion syndrome plays an important role in this scenario. Aim: To access effects of different post-conditioning cycles on mesenteric ischemia-reperfusion syndrome. Method: Twenty-five rats were assigned into five groups: Sham, used to establish normal parameters; control group, submitted to mesenteric ischemia for 30 min; in groups GP3, GP1 and GP30, ischemia was followed by post-conditioning protocol, which consisted of 1 cycle of 3 min (GP3), 3 cycles of 1 min (GP1) or 6 cycles of 30 s (GP30), respectively. Ileum samples were harvested after one hour of reperfusion. Intestinal mucosal injury was evaluated through histopathological analysis. Results: The average of mesenteric injury degree was 0 in the sham group, 3.6 in the control group, 3.4 in GP3, 3.2 in GP1, and 3.0 in GP30; villous length average was 161.59 in sham group, 136.27 in control group, 135.89 in GP3, 129.46 in GP1, and 135.18 in GP30. Was found significant difference between sham and other groups (p<0.05); however, there was no difference among post-conditioning groups. Conclusion: Post-conditioning adopted protocols were not able to protect intestinal mucosa integrity after mesenteric ischemia and short term reperfusion.
RESUMO Racional: O desfecho satisfatório na abordagem cirúrgica da obesidade deve contemplar, além da perda de peso, alteração significativa nas comorbidades preexistentes e na qualidade de vida dos pacientes. Objetivo: Avaliar a qualidade de vida no pós-operatório tardio de pacientes submetidos à cirurgia de gastrectomia vertical por videolaparoscopia. Métodos: Foi aplicado o questionário "Bariatric Analysis and Reporting Outcome System" (BAROS) em pacientes submetidos à gastrectomia vertical por videolaparoscopia. Resultados: Foram avaliados 47 pacientes, entre 21 e 60 anos de idade. O IMC médio antes da operação era 43,06±5,87 kg/m². A média percentual de redução do excesso de peso após foi de 85,46±23,6%. A pontuação obtida pelos pacientes no questionário sobre a melhora na qualidade de vida evidenciou resultado excelente (36,17%), ótimo (40,43%), bom (21,28%) e razoável (2,13%). Houve melhora clínica após a operação em todas as comorbidades investigadas. Conclusão: A perda de peso foi fundamental para a melhoria na qualidade de vida e proporcionou resolução ou a melhora clínica em todas as comorbidades investigadas.
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Animals , Male , Rats , Reperfusion/methods , Reperfusion Injury/prevention & control , Ischemic Postconditioning/methods , Mesenteric Ischemia/prevention & control , Mesentery/blood supply , Time Factors , Clinical Protocols , Rats, WistarABSTRACT
Objective To investigate the effects of sevoflurane post-conditioning on oxidative stress and inflammatory reaction during rat cerebral ischemia-reperfusion, and to explore its cerebral protective mechanism.Methods Thirty-six health male Sprague-Dawley rats (aged 12-14 weeks, weighing 220-260 g) were randomly divided into 3 groups (n=12 each): sham control group (group Sham), cerebral ischemia-reperfusion group (group IR), sevoflurane post-conditioning group (group SPC).Cerebral ischemia-reperfusion model was established, ischemia for 30 min followed by reperfusion 24 h.Rat middle cerebral artery was not occluded in group Sham.Cerebral ischemia-reperfusion model was established in group IR.Group SPC was subjected to 2.6% sevoflurane for 15 min in the beginning of reperfusion.At the end of reperfusion, rats were cut off the head to take out the brain tissue.The expression level of Iba-1 and HO-1 proteins was measured by western blot.The levels of reactive oxygen species (ROS), malondialdehyde (MDA), TNF-α, IL-1β and the activity of superoxide dismutase (SOD) were evaluated.Results Compared with group Sham, the expression of cerebral cortex Iba-1 protein was higher than that in groups IR and SPC (P＜0.05), the expression of Iba-1 protein in group SPC was lower than that in group IR (P＜0.05).Compared with group Sham, the contents of ROS, MDA, TNF-α and IL-1β were increased in groups IR and SPC (P＜0.05), but the activity of SOD and expression of HO-1 protein were decreased (P＜0.05).And the contents of ROS, MDA, TNF-α and IL-1β in group SPC were less than those in group IR, the activity of SOD and expression of HO-1 protein in group SPC were higher than those in group IR.Conclusion Sevoflurane post-conditioning can mitigate the microglia activation, reduce cerebral oxidative stress and inflammation, thus protect rat cerebral against ischemia reperfusion injury.
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Objective:To evaluate the effect of post-conditioning in brain injury induced by myocardial I/R on inflammatory factor and GFAP.Methods:Male Sprague-Dawley rats were randomly allocated into 3 groups (n=8):group Sham,group IR,group IPost.Myocardial IR was induced by occlusion of the anterior descending branch of the left coronary artery for 30 min.group IPost received 3 cycles of 10 s reperfusion followed by 10 s ischemia at the end of myocardial ischemia.The rats were sacrificed at 120 rain of reperfusion and the brains were removed for microscopic examination,inflammatory factors and GFAP.Results:Compared with group Sham,IL-6,IL-8 were significantly increased,IL-10 was down-regulated in group IR(P＜0.01).Post-conditioning can decrease IL-6,IL-8 and up-regulated IL-10(P＜0.01).When compared with group Sham,the expression of GFAP was higher in group IR(P＜0.05),however,the GFAP in group IPost is the most among these three groups(P＜0.01).Conclusion:Post-conditioning could protect brain by decreasing inflammatory factors,increasing GFAP,which both from brain injury induced by myocardial ischemia reperfusion.
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Objective To evaluate the role of mitochondrial ATP-seusitive potassium (mito-KATP) channels in sevoflurane postconditioning-induced inhibition of oxygen-glucose dcprivation and restoration (OGD/R)-induced pyroptosis in primary rat cardiomyocytes.Methods Cardiomyocytes of newborn Sprague-Dawley rats (＜48 h after birth) were cultured in vitro and seeded in 6-well dishes (2 cm in diameter)or in 96-well plates.The cells were divided into 6 groups (n =15 each) using a random number table:control group (group C),OGD/R group (group O),sevoflurane postconditioning group (group Sev),sevoflurane postconditioning plus 5-hydroxydecanoate (5-HD) group (group SH),5-HD group (group H) and OGD/R plus 5-HD group (group HO).The cardiomyocytes were subjected to oxygen-glucose deprivation for 4 h followed by restoration of oxygen-glucose supply for 24 h.After oxygen-glucose restoration,the cardiomyocytes in the culture media were exposed to 2％ sevoflurane for 1 h to perform sevoflurane postconditioning.At 1 h before oxygen-glucose deprivation,a specific mito-KATP channel blocker 5-HD 100 μmol/L was added to the culture media.Cardiomyocytes were cultured in normal culture atmosphere in group C.Cardiomyocytes were collected at 24 h of oxygen-glucose restoration.Cell pyroptosis was detected by double flow cytometry AlexaFour488 (caspase-1 FLICA staining) and TMR red (DNA staining) staining.The pyroptosis rate was calculated.The cell survival rate was measured by methyl thiazolyl tetrazolium assay.The content of reactive oxygen species (ROS) in mitochondria was determined by 2',7'-dichlorofluorescin diacetate assay.The mitochondrial membrane potential (MMP) was measured by using JC-I fluorescent probe.The expression of interleukin-1beta (IL-1β) was determined by Western blot.Results Compared with group C,the pyroptosis rate and ROS content were significantly increased,the cell survival rate and MMP were decreased,and the expression of IL-1β was up-regulated in group O (P＜0.05).Compared with group O,the pyroptosis rate and ROS content were significantly decreased,the cell survival rate and MMP were increased,and the expression of IL-1β was down-regulated in group Sev (P＜0.05).Compared with group Sev,the pyroptosis rate and ROS content were significantly increased,the cell survival rate and M MP were decreased,and the expression of IL-1β was up-regulated in group SH (P＜0.05).Compared with group SH,the pyroptosis rate and ROS content were significantly increased,the cell survival rate and MMP were decreased,and the expression of IL-1β was up-regulated in group H O (P＜0.05).Conclusion The mechanism by which sevoflurane postconditioning inhibits OGD/R-induced pyroptosis in primary rat cardiomyocytes is probably associated with increasing mito-KATP channel opening.
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Objective To evaluate the role of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) in diabetes mellitus-induced reduction of hypoxic postconditioning (HPO)-induced protection of cardiomyocytes and the relationship with glycogen synthase kinase-3β (GSK-3β)-mediated mitochondrial apoptotic pathway.Methods H9c2 cells incubated in high-glucose (30 mmol/L) medium for 24 h were divided into 6 groups (n =5 each) using a random number table:normoxia group (group N),hypoxia-reoxygenation (H/R) group,group HPO,PTEN gene silencing normoxia group (group P-N),PTEN gene silencing H/R group (group P-H/R),and PTEN gene silencing HPO group (group P-HPO).H9c2 cells were exposed to 95％ N2-5％ CO2 for 4 h followed by 2 h reoxygenation with 90％ O2-10％ CO2.HPO was induced by 3 cycles of 5 min reoxygenation followed by 5 min hypoxia before reoxygenation.At the end of reoxygenation,the level of lactate dehydrogenase (LDH) in the supernatant was detected by enzyme-linked immunosorbent assay,the changes in mitochondrial membrane potential (MMP were assessed by JC-1 fluorescence assay,the cell apoptosis was detected by AnnexinV-FITC/PI flow cytometry,and the expression of PTEN and phosphorylated GSK-3β (p-GSK-3β) was determined by Western blot.The JC-1 monomer/polymer ratio and apoptosis rate were calculated.Results Compared with group N,the amount of LDH released,JC-1 monomer/polymer ratio and apoptosis rate were significantly increased,and the expression of PTEN was up-regulated in H/R and HPO groups (P＜0.05).There was no significant difference in the parameters mentioned above between group H/R and group HPO (P＞0.05).Compared with group HPO,the amount of LDH released,JC-1 monomer/polymer ratio and apoptosis rate were significantly decreased,PTEN expression was down-regulated,and the expression of p-GSK-3β was up-regulated in group P-HPO (P＜0.05).Compared with group N,the expression of PTEN was significantly down-regulated,and no significant changes were found in the other parameters mentioned above in group P-N (P＞0.05).Compared with group H/R,the expression of PTEN was significantly down-regulated,and no significant changes were found in the other parameters mentioned above in group P-H/R (P＞0.05).Conclusion PTEN is involved in diabetes mellitus-induced reduction of HPO-induced protection of cardiomyocytes,and the mechanism is associated with PTEN-induced activation of GSK-3β-modulated mitochondrial apoptotic pathway.
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Objective To evaluate the effect of emulsified isoflurane post-conditioning on the mitochondrial function during lung ischemia-reperfusion (I/R) in rats in an in vitro experiment.Methods Twenty-four SPF healthy male Sprague-Dawley rats,weighing 250-300 g,were used in the study.After the animals were anesthetized,the lungs were removed,connected to the perfusion system and then divided into 4 groups (n=6 each) using a random number table:control group (group C),group I/R,emulsified isoflurane post-conditioning group (group EI) and intralipid post-conditioning group (group IL).After 20 min of equilibration,the lungs were continuously perfused for 105 min in group C,and the lungs were subjected to 45 min ischemia followed by 60 min reperfusion to establish the model of lung I/R injury in the other three groups.During the reperfusion period,the common perfusate was used in group I/R,the perfusate containing 1.68 mmol/L emulsified isoflurane was used in group EI,and the equal volume of perfusate containing 30％ intralipid was used in group IL.At the end of the equilibration (T0),immediately after beginning of reperfusion (T1) and at 30 and 60 min of reperfusion (T2.3),the arterial oxygen partial pressure (PaO2),airway resistance,pulmonary compliance and tidal volume (VT) were recorded.The right upper lobe of the lung was removed at T3 for determination of wet to dry weight ratio (W/D ratio).The right middle lobe of the lung was removed at T3 for pathologic examination with light microscope.The contents of reactive oxygen species (ROS),NAD+ and ATP in lung tissues were detected.Results Compared with group C,the PaO2,pulmonary compliance and Vr were significantly decreased,and the airway resistance was increased at T1-3,and the W/D ratio and ROS content were increased,and NAD+ and ATP contents were decreased at T3 in I/R,EI and IL groups (P＜0.05).Compared with I/R and IL groups,the PaO2,pulmonary compliance and VT were significantly increased,and the airway resistance was decreased at T2.3,and the W/D ratio and ROS content were decreased,and NAD+ and ATP contents were increased at T3 in group EI (P＜0.05).The pathologic changes of lungs were significantly attenuated in group EI as compared with group I/R.Conclusion The mechanism by which emulsified isoflurane post-conditioning attenuates lung I/R injury is related to decrease in mitochondrial dysfunction in rats in an in vitro experiment.
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Objective:To explore the effect of remote ischemic post-conditioning (RIPoC) on oxidation/reduction response, energy metabolism and inlfammatory reaction of ischemic myocardial tissue in rats with ischemic reperfusion (IR) injury. Methods:IR model was established by 30 min left anterior descending (LAD) artery occlusion followed by 120 min reperfusion, conditioning was defined as 3 cycles of 30 seconds ischemia followed by 30 seconds reperfusion in adult rats. The rats were divided into 5 groups:①ischemic pre-conditioning (IPC) group, the rats received the conditioning prior to IR treatment,②ischemic post-conditioning (IPoC) group, the rats received 30 min LAD occlusion followed by conditioning at the beginning of 120 min reperfusion, ③ remote ischemic post-conditioning(RIPoC) group, the rats received 30 min LAD occlusion, followed by femoral artery conditioning at the beginning of 120 min reperfusion, ④ IR group, ⑤ Sham group. n=8 in each group.Ischemic myocardial tissue was collected at the end of experiment, superoxide dismutase (SOD) activity was assayed by xanthine oxidase method,malondialdehyde (MDA) content was examined by thiobarbituric acid method, myeloperoxidase (MPO) activity was determined by chemistry colorimetric method, adenosine triphosphate(ATP)amount was measured by bioluminescence method;expressions of myocardial stromal cell derived factor-1 (SDF-1) and vascular endothelial growth factor (VEGF), mitochondrial function related genes Ndufa2, Ndufa4, Cox4il and Cox7a2 were evaluated by real time quantitative PCR. Results:In IPC, IPoC and RIPoC groups, the ischemic myocardial tissue had increased SOD activity and ATP amount, decreased MDA content and MPO activity; induced expressions of SDF-1, VEGF, mitochondrial function related genes Ndufa2, Ndufa4, Cox4il and Cox7a2. Conclusion:RIPoC may increase anti-oxidation/reduction response, protect energy metabolism and reduce inlfammatory reaction in ischemic myocardial tissue, the effect was similar to pre-conditioning and post-conditioningin rats with IR injury.
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Objective To explore the effects of hypoxic post-conditioning on cognitive function and the expression of silent information regulator 1 (SIRT1) in hippocampal CA1 of rats with cerebral ischemia. Methods Sixty Sprague-Dawley rats were randomly divided into sham operation group, model group and treatment group with 20 cases in each group. Each group was divided into one day, two days, three days, seven days subgroups according to the time of ischemia reperfusion. Global cerebral ischemia reperfusion was induced with modified Pulsinelli′4-vessel occlusion. The treatment group received 8%oxygen for two hours after ischemia. The cognitive function was assessed with Morris water maze test. Morphological changes of the hippocampal CA1 region were observed by HE staining. The expression of SIRT1 in the hippocampal CA1 region was detected with immunohistochemical assay and Western blotting. Results Compared with the model group, the escape latency significantly shortened (P<0.05), the number of times crossing the platform increased (P<0.05), the speed and the percentage of time spent in the platform quadrant increased (P<0.05), and the total distance decreased (P<0.05);the expression of SIRT1 in hippocampal CA1 increased (P<0.05) and the number of normal neurons increased (P<0.05) in the treatment group. Conclusion Hypoxic post-conditioning can improve the cognitive function of rats with global cerebral ischemia, which may relate with up-regulating SIRT1 in hippocampus.
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Objective To investigate the effects of limb ischemic post-conditioning (LIpostC) alone or its combination with therapeutic hypothermia (TH) on systemic inflammatory response and lung injury after cardiac arrest (CA) and resuscitation. Methods Twenty-one healthy male pigs weighing (37±2) kg were randomly divided into 3 groups (n = 7 each): control group, LIpostC group, and LIpostC+TH group. The animal model was established by 10 minutes of untreated CA and then 5 minutes of cardiopulmonary resuscitation (CPR).Coincident with the start of CPR, LIpostC was induced by four cycles of 5 minutes of limb ischemia followed by 5 minutes of reperfusion in the LIpostC and LIpostC+TH groups. After successful resuscitation, TH was implemented by surface cooling to reach a temperature of 32-34℃ until 4 hours post-resuscitation, followed by a re-warming rate of 1 ℃/h for 4 hours in the LIpostC+TH group. Normal temperature was maintained in the control and LIpostC groups. The resuscitation outcomes in each group were recorded during CPR. At 15 minutes prior to CA (baseline) and during 4 hours post-resuscitation, the level of arterial lactate was measured and PaO2/FiO2 was calculated, and extra-vascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) were measured meanwhile by a PiCCO monitor. At 15 minutes prior to CA (baseline) and during 24 hours post-resuscitation, the levels of serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by enzyme linked immunosorbent assay (ELISA). Results Six animals in each group were successfully resuscitated. Coronary perfusion pressure (CPP), duration of resuscitation, number of shocks and epinephrine dosage during CPR were not statistically significant among the three groups. The baseline of arterial lactate, PaO2/FiO2, EVLWI, PVPI and cytokines prior to CA were also not statistically significant among the three groups. The levels of serum TNF-α and IL-6 after resuscitation were gradually increased in all the three groups; however, the values of TNF-αand IL-6 were significantly lower in the LIpostC and LIpostC+TH groups than that in the control group, and they were further decreased in the LIpostC+TH group when compared to the LIpostC group [TNF-α (ng/L): 305±22 vs. 343±26 at 4 hours, 350±29 vs. 389±18 at 24 hours; IL-6 (ng/L): 239±14 vs. 263±19 at 24 hours, all P < 0.05]. The levels of lactate reached the peak at 2 hours post-resuscitation and then gradually decreased in all the three groups; it finally returned to the baseline in the LIpostC and LIpostC+TH groups, which was markedly lower than that in the control group (mmol/L: 1.4±0.7, 1.2±0.3 vs. 3.1±1.7, both P < 0.05). During 4 hours post-resuscitation, PaO2/FiO2 was significantly higher and EVLWI and PVPI were markedly lower in the LIpostC and LIpostC+TH groups than that in the control group; additionally, PaO2/FiO2 and EVLWI were further improved in the LIpostC+TH group than the LIpostC group [4-hour PaO2/FiO2 (mmHg, 1 mmHg = 0.133 kPa): 391±26 vs. 361±20; 4-hour EVLWI (mL/kg): 10.1±1.5 vs. 12.1±1.2, both P < 0.05]. Conclusion LIpostC can be used to alleviate systemic inflammatory response and lung injury after porcine CA and CPR, and its combination with TH further enhanced its protective effects.
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Objective: To observe the protective effect of ischemic post-conditioning on myocardial reperfusion injury with the potential mechanism in experimental rabbits. Methods: A total of 36 healthy New Zealand rabbits were divided into 6 groups:①Sham group,②Ischemic reperfusion control (CON) group,③Myocardial ischemic post-conditioning (MpostC) group,④Remote ischemic post-conditioning (RPostC) group,⑤MPostC+5-HD group,⑥RPostC+5-HD group.n=6 in each group. The ischemic reperfusion injury model was established by left ventricular descending artery occlusion for 45 min followed by reperfusion for 120 min. Bilateral external iliac artery was occluded for 5 min to induce the short skeletal muscle ischemia. The indexes of cardiac function and plasma CK , LDH activities were measured at baseline, end of ischemia and 1, 2 h after reperfusion respectively, the sizes of myocardial infarction (MI) were examined and compared among different groups. Results: ①Compared with CON group, the indexes of cardiac function were improved in MPostC and RPostC groups at 1, 2 h after reperfusion,P0.05. The MI ranges and areas in MPostC and RPostC groups were much less than that in CON group,P0.05. Conclusion: Classical ischemic post-conditioning and remote organ ischemic post-conditioning both have protective effect on myocardial reperfusion injury in experimental rabbit, which might be related to the activation of mitochondrial ATP-sensitive potassium channels.
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Objective: To investigate the effect of adiponectin levels with its related mechanism in diabetic myocardial ischemia-reperfusion injury and ischemia post-conditioning in experimental rats. Methods: A total of 80 male SD rats were randomly divided into 6 groups: Normal sham (NS) group,n=8, Normal ischemia-reperfusion injury (NIRI) group,n=16, Normal ischemia post-conditioning (NIPO) group,n=16 and Diabetic mellitus sham (DMS) group,n=8, Diabetic mellitus ischemia-reperfusion injury (DMIRI) group,n=16, Diabetic mellitus ischemic post-conditioning (DMIPO) group,n=16. DM rats model was established by intraperitoneal injection of streptozotocin; IR model was established by occlusion of left anterior descending (LAD) coronary artery for 30 min followed by reperfusion for 120min; IPO model was established by 3 cycles of ischemia for 10s and reperfusion for10s; the rats in Sham group received silk line wrapping of LAD without occlusion. The myocardial infarction (MI) area was measured by TTC staining, plasma adiponectin level was examined by ELISA, the protein expressions of p-Akt and total-Akt were detected by Western blot analysis. Results: Compared with NIRI group, NIPO group had decreased MI area,P<0.05, while DMIRI group and DMIPO group had increased MI area,P<0.01; compared with NS group, NIRI group and NIPO group showed up-regulated expression of adiponectin and p-Akt,P<0.05 and DMS group showed down-regulated p-Akt,P<0.05. Compared with NIPO group, three DM groups presented down-regulated adiponectin and p-Akt,P<0.05. Linear correlation analysis indicated that plasma adiponectin expression level was negatively related to MI area and positively related to myocardial tissue p-Akt expression with the correlation coefifcient at 0.63 and 0.65 respectively, P<0.01. Conclusion: Down-regulated plasma adiponectin expression may cause the inactivation of PI3K/Akt signal pathway and therefore aggravate DM ischemia-reperfusion injury which cannot be protected by ischemic post-conditioning in experimental rats.