Reperfusion Group Research Articles

Role of mitochondrial ATP-sensitive potassium channels in dexmedetomidine-induced attenuation of myocardial ischemia-reperfusion injury in rats

Objective To evaluate the role of mitochondrial ATP-sensitive potassium (mito-KATP) channels in dexmedetomidine-induced attenuation of myocardial ischemia-reperfusion (I/R) injury in rats. Methods Forty pathogen-free healthy male Sprague-Dawley rats, aged 8-12 weeks, weighing 200-350 g, were divided into 5 groups (n=8 each) using a random number table: sham operation group (group S), I/R group, dexmedetomidine group (group DEX), a specific mito-KATP channel blocker 5-hydroxydecanoate (5-HD) group (group 5-HD) and dexmedetomidine plus 5-HD group (group DEX+ 5-HD). Myocardial I/R was produced by occlusion of the anterior descending branch of the left coronary artery for 30 min followed by 120 min reperfusion in pentobarbital sodium-anesthetized rats.Dexmedetomidine 5 μg/kg was intraperitoneally injected at 15 min prior to reperfusion in group DEX.5-HD 40 mg/kg was intraperitoneally injected at 30 min prior to reperfusion in group 5-HD.In group DEX+ 5-HD, 5-HD 40 mg/kg and dexmedetomidine 5 μg/kg were intraperitoneally injected at 30 and 15 min prior to reperfusion, respectively.The parameters of cardiac function such as left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and the maximum rate of increase or decrease in left ventricular pressure (±dp/dtmax) were recorded before ischemia (T0) and at 60 and 120 min of reperfusion (T1, 2). Blood samples were collected from the carotid artery at the end of reperfusion for determination of the concentrations of creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) in serum.The animals were then sacrificed, and hearts were removed for determination of the myocardial infarct size in the left ventricular myocardial tissues. Results Compared with group S, the LVSP and ±dp/dtmax were significantly decreased, and the LVEDP was increased at T1-2, and the concentrations of CK-MB and cTnI in serum and myocardial infarct size were increased in the other groups (P 0.05). Compared with group DEX, the LVSP and ±dp/dtmax were significantly decreased, and the LVEDP was increased at T1-2, and the concentrations of CK-MB and cTnI in serum and myocardial infarct size were increased in DEX+ 5-HD group (P<0.05). Conclusion The mechanism by which dexmedetomidine attenuates myocardial I/R injury is partially related to promotion of mito-KATP channel opening in rats. Key words: KATP channels; Dexmedetomidine; Myocardial reperfusion injury

Changes in APPL1 expression during renal fibrosis in a mouse model of renal ischemia-reperfusion injury

Objective To evaluate the changes in the expression of adaptor protein containing pleckstrin homobgy domain, phosphotyrosine-binding domain and a leucine zipper motif 1(APPL1)during renal fibrosis in a mouse model of renal ischemia-reperfusion(I/R)injury. Methods Twenty-four male C57BL/6 mice, aged 8 weeks, weighing 20-25 g, were divided into 2 groups(n=12 each)using a random number table: sham operation group(S group)and renal I/R group.The model of renal I/R injury was established by clipping the bilateral renal pedicles for 30 min followed by reperfusion in group I/R.Six mice were selected at 2 days of reperfusion, and venous blood samples were collected for determination of serum concentrations of blood urea nitrogen and creatinine.The animals were then sacrificed, the renal specimens were obtained for microscopic examination of tubular necrosis with a light microscope, and the damage to the renal tubules was scored using a semi-quantitative method.Six mice were sacrificed at 14 days of reperfusion, and the renal specimens were obtained for assessment of the degree of renal fibrosis(using picric acid-sirius red staining)and for determination of the expression of collagen type 1, fibronectin and α-smooth muscle actin in renal tissues(by Western blot or immunofluorescence method). At 2 and 14 days of reperfusion, the expression of APPL1 in renal tissues was detected by Western blot and the expression of APPL1 mRNA in renal tissues by real-time polymerase chain reaction. Results Compared with group S, the serum concentrations of blood urea nitrogen and creatinine, scores of renal tubular damage and degree of renal fibrosis were significantly increased at 2 days of reperfusion, the expression of collagen type 1, fibronectin and α-smooth muscle actin in renal tissues was up-regulated at 14 days of reperfusion, and the expression of APPL1 protein and mRNA was up-regulated at 2 and 14 days of reperfusion in group I/R(P<0.05). Conclusion Up-regulated expression of APPL1 may be involved in the process of renal fibrosis in a mouse model of renal I/R injury. Key words: Fibrosis; Kidney; Ischemia-reperfusion; Adaptor proteins, signal transducing

Study of the protective effect of ischemic and pharmacological preconditioning on hepatic ischemic reperfusion injury induced in rats.

Background and AimHepatic ischemia reperfusion injury is the main cause of liver failure following liver surgery, so an effective method is needed to prevent or reduce this hepatic injury. The aim of the present study is to investigate the potential effect of ischemic preconditioning versus pharmacological preconditioning with lisinopril or verapamil for protection against hepatic ischemia reperfusion injury induced in rats.MethodsRats were divided into six groups. Group I served as control untreated. Rats of group II were subjected to laparotomy without induction of ischemia reperfusion. Ischemia reperfusion by ligation of the portal trait for 30 min, followed by reperfusion for 2 h, was performed in rats of groups III–VI. Ischemic preconditioning was performed for rats of group IV before induction of ischemia reperfusion. Lisinopril and verapamil was given daily for 3 days before induction of ischemia reperfusion in groups V and VI, respectively. Serum level of liver transaminases and liver malondialdehyde content were measured, and hepatic histopathological examination was assessed.ResultsInduction of ischemia reperfusion resulted in significant elevation of liver transaminases and liver malondialdehyde content associated with significant hepatic histopathological injury that were significantly improved by ischemic preconditioning, lisinopril, or verapamil treatment. Verapamil showed the most significant improvement compared with ischemic preconditioning or lisinopril treatment.ConclusionIschemic preconditioning and pharmacological preconditioning by lisinopril or verapamil can protect against hepatic ischemia reperfusion probably through inhibition of oxidative stress and neutrophil infiltration. The most potent protection is demonstrated by verapamil treatment.

Hyperbaric oxygenation and the genic expression related to oxidative stress in the heart of mice during intestinal ischemia and reperfusion.

To investigate the effects of hyperbaric oxygenation (HBO) on intestinal ischemia and reperfusion (IR) injury, we evaluated the expression of 84 genes related to oxidative stress and the antioxidant response in mouse hearts. Four groups were subjected to 60 minutes of intestinal ischemia followed by 60 minutes of reperfusion: IRG, ischemia and reperfusion group without HBO; HBO-IG, which received HBO during ischemia; HBO-RG, which received HBO during reperfusion; and HBO-IRG, which received HBO during ischemia and reperfusion. The control group (CG) underwent anesthesia and laparotomy and was observed for 120 minutes. The (RT-qPCR) method was applied. Genes with expression levels three times below or above the threshold cycle were considered significantly hypoexpressed or hyperexpressed, respectively (Student's t-test p<0.05). Eight genes (9.52%) were hyperexpressed in the IRG. When the HBO groups were compared to the IRG, we found a decrease in the expression of eight genes in the HBO-IG, five genes in the HBO-RG, and seven genes in the HBO-IRG. The reduction in the expression of genes related to oxidative stress and antioxidant defense following HBO in mouse hearts resulting from intestinal IR injury was more favorable during the ischemic period than during the reperfusion period.

Need for refining successful revascularization in endovascular treatment of acute ischemic stroke: Data from real-world

IntroductionModified TICI (mTICI) score≥2b has been largely used as a definition of successful revascularization in acute stroke endovascular treatment (EVT). However, mTICI 2b encompasses a broad range of different revascularization states and its clinical relevance, comparing to mTICI 3, has been questioned. We aimed to compare clinical outcomes between these two reperfusion groups, in patients submitted to EVT for anterior circulation large-vessel occlusion, in a real-world setting. Materials and methodsRetrospective statistical analysis of our database of consecutive EVTs. ResultsOur study population of 178 patients has a mean age of 71years, 46.6% males, median baseline NIHSS of 17 and ASPECTS of 8. There were no statistically significant differences in baseline characteristics and interventional procedure data between groups. A significantly higher rate of mRS≤1 at 3months (OR=2.33, 95%CI 1.03–5.25) and lower rate of total (OR=0.18, 95%CI 0.06–0.53) and symptomatic intracranial hemorrhage (OR=0.08, 95%CI 0.01–0.74) was seen in mTICI 3 group. This group also showed non-significant trend (adjusted p=0.071) toward higher percentages of mRS≤2 (71.8% versus 51.5%) and lower mortality at 3months (6.4% versus 19.1%). ConclusionsIn accordance with previous reports from clinical trials, these real-world data suggest that is probably time to refine the definition of successful revascularization in acute stroke EVT.

Study the Effect of Apocynin on Some Renal Functions in Ischemia / Reperfusion Injury in Male Albino Rats

Background: Apocynin (4-hydroxy-3-methoxyacetophenone) which isolated from the traditional medicinal plant Picrorhiza kurroa, is a naturally occurring methoxy-substituted catechol, experimentally used as an inhibitor of NADPH oxidase and of the concomitant ROS production. Apocynin also proved to be a potent anti-inflammatory agent, based on the selective inhibition of the production of ROS by activated human PMNs. Aim of the Study: to explore the protective effect of Apocynin and the NADPH oxidase inhibitor on kidney damage induced by ischemia/reperfusion (I/R) in a rat model. Subjects and Methods: Fourty male albino rats were categorized into four equal groups of 10. Group 1: Sham operated control group, Group 2: Ischemia / reperfusion (I/R) group; which underwent bilateral renal ischemia for 1 hour followed by a 23 hour reperfusion, Group 3: 4-week Apocynin treated group in which rats received Apocynin with a dose o16 mg/kg /day for 4 weeks followed by bilateral renal ischemia for 1 hour then 23 hour reperfusion afterwards , and Group 4: 8-week Apocynin treated group in which rats received Apocynin with a dose of 16 mg/kg /day for 8 weeks then bilateral renal ischemia for 1 hour followed by 23 hour reperfusion. After reperfusion, the animals were sacrificed, the blood samples were collected for determination of blood urea nitrogen, serum creatinine, 24 hour urine were collected for determination of creatinine clearance. Kidneys of all animals were harvested and evaluated biochemically through determination of tissue MDA, MPO, GPX and catalase level. Results: Kidney tissue MDA, MPO, serum BUN and Creatinine levels were found to be significantly higher in the I/R group. GPx level showed a significant decrease, while there was a slight decrease in Catalase level when compared with Sham operated group. Creatinine clearance was impaired in renal I/R group. Renal I/R injury has also induced an extensive tubular necrosis, glomerular damage, and apoptosis. Apocynin significantly reduced MDA and MPO and increased GPX and catalase in both treatment groups when compared to the I/R group (p< 0.001). The elevated BUN and creatinine levels were significantly reduced in treatment groups, also creatinine clearance was restored to around normal value. Conclusion: with accordance to the findings and outcome of the present study, Apocynin has exerted protective effects against ischemia/reperfusion injury by ameliorating the kidney damage induced by I/R injury to a significant extent. However, there was no significant difference in the outcome if the treatment was extended from 4 to 8 weeks.

Study of Total Flavonoids from Mao Dongqing in Cerebral Ischemia Reperfusion Models

Objective Mao Dongqing (MDQ) is the dried root of Ilex pubescens Hook. et Arn. It is a renowned traditional Chinese medicine which has been used for the treatment of acute and chronic cardio-cerebrovascular diseases in the clinic for many years. The aim of this study was to further understand the effect of total flavonoids from MDQ on cerebral ischemia reperfusion injury. Methods Ginaton group (extract of ginkgo biloba leaves injection), the small, middle and large doses of total flavonoids from the MDQ group were given related drugs via intragastric administration before the operation. The sham operation group, ischaemic preconditioning model group and ischemia reperfusion group were given the same volume of 0.1% CMC daily for 10 days. After the last administration, animal models of cerebral ischemia reperfusion injury in mice were established using the method of blocking the bilateral common carotid artery for 10 min, restoring perfusion for 10 min, bilateral carotid artery occlusion for 10 min, and then reperfusion for 24 hours. Half of the brain was fixed in 10% formalin for HE staining. The other half of the brain was used to prepare brain homogenate, which was used to determine the content of ATPase, NO and NOS. Results We found that the models with cerebral ischemia reperfusion injury in mice were copied successfully. Large and medium doses of total flavonoids from MDQ could significantly reduce the content of NO, tNOS, iNOS and increase the activity of ATPase in brain tissue of mice. Total flavonoids from MDQ could also reduce the pathological changes of the hippocampus and cortical neuron cells in the hippocampus of mice. Conclusion The results of this study showed that the model of cerebral ischemia-reperfusion in mice was successful. The total flavonoids from MDQ could achieve the role of anti-cerebral ischemia injury by inhibition of the inflammatory cascade, improving the imbalance of oxygen supply and demand and the disorder of glucose metabolism, inhibiting the apoptosis of nerve cells during cerebral ischemia reperfusion injury. Acknowledgment National “Significant New Drug Creation” science and technology major special project (2009Z × 09103-324).

The role of histone deacetylase inhibitors in regulation of Akt/GSK-3β signaling pathway in mice following transient focal cerebral ischemia.

To investigate whether the neuroprotective effect of TSA on cerebral ischemia reperfusion injury is mediated by the activation of Akt/GSK-3β signaling pathway. Mice were randomly divided into four groups (n=15): sham group (S); ischemia reperfusion group (IR); ischemia reperfusion and pretreated with TSA group (IR+T); ischemia reperfusion and pretreated with TSA and LY294002 group (IR+T+L). The model of cerebral ischemia reperfusion was established by 1h of MCAO following 24h of reperfusion. TSA (5mg/kg) was intraperitoneally given for 3 days before MCAO, Akt inhibitor, LY294002 (15 nmol/kg) was injected by tail vein 30 min before the MCAO. TSA significantly increased the expression of p-Akt, p-GSK-3β proteins and the levels of SOD, Bcl-2, reduced the infarct volume and the levels of MDA, ROS, TNF-α, IL-1β, Bax, Caspase-3, TUNEL and attenuated neurological deficit in mice with transient MCAO, LY294002 weakened such effect of TSA dramatically. TSA could significantly decrease the neurological deficit and reduce the cerebral infarct volume, oxidative stress, inflammation, as well as apoptosis during cerebral ischemia reperfusion injury, which was achieved by activation of the Akt/GSK-3β signaling pathway.

Effects of Apigenin on Experimental Ischemia/Reperfusion Injury in the Rat Ovary.

Background:Apigenin is a plant-derived compound belonging to the flavone class, which possess antioxidant, free-radical-scavenging and anti-inflammatory properties.Aims:To address the effects of apigenin on serum anti-mullerian hormone levels, tissue oxidative stress parameters and histopathological changes in ovarian ischemia/reperfusion injury.Study Design:Animal experiment.Methods:Twenty-eight female Wistar albino rats were randomly separated into four sections: Sham operation (group 1), ischemia/reperfusion plus saline (group 2), ischemia/reperfusion plus dimethyl sulfoxide (group 3) and ischemia/reperfusion plus apigenin (group 4). In all ischemia/reperfusion groups, a bilateral adnexal 3-h period of ischemia was performed, followed by 3-h of reperfusion. A single dose of 15 mg/kg apigenin was given intraperitoneally 60 min before reperfusion in group 4. After 3-h of reperfusion, both ovaries were removed, and blood samples were collected. The main outcome measures were serum anti-mullerian hormone levels, ovarian tissue malondialdehyde, total nitric oxide, Cu/Zn superoxide dismutase, catalase and glutathione levels and histopathological damage scores.Results:The ovarian tissue nitric oxide level was significantly lower, and the glutathione level was significantly higher in group 4 compared with groups 2 and 3. There was no significant difference in anti-mullerian hormone levels among the three ischemia/reperfusion groups. The histopathological damage score was lower in group 4 than in groups 2 and 3 (p>0.05).Conclusion:Administration of apigenin has no significant protective effect on ovarian reserve and tissue damage in ovarian ischemia/reperfusion injury.

Effect of hydromorphone postconditioning on electrophysiological stability during ischemia-reperfusion in isolated rat hearts

Objective To evaluate the effect of hydromorphone postconditioning on the electrophysiological stability during ischemia-reperfusion (I/R) in isolated rat hearts. Methods Healthy adult male Sprague-Dawley rats, aged 2-3 months, weighing 280-360 g, were heparinized and anesthetized with pentobarbital sodium.Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95% O2-5% CO2 at 37 ℃.Twenty-four Langendorff-perfused hearts were divided into 3 groups (n=8 each) using a random number table: control group (group C), I/R group and hydromorphone postconditioning group (group HM). The isolated hearts were subjected to 60 min ischemia followed by 60 min reperfusion to establish the model of isolated heart I/R injury.The isolated hearts were perfused with K-H solution containing 4.1 ng/ml hydromorphone for 10 min starting from onset of reperfusion in group HM.Heart rate, electrocardiogram, coronary flow, and monophasic action potential amplitude, in the left ventricular endocardium, mid-myocardium and epicardium the maximal increase rate (Vmax) at the 0 phase, and monophasic action potential duration at 50% and 90% repolarization (MAPD50 and MAPD90, respectively) were recorded at 20 min of stabilization (T0) and 10, 25, 40 and 60 min of reperfusion (T1-4). The transmural dispersion of repolarization (TDR) was calculated, and the time for restoration of spontaneous heart beat was recorded. Results There was no significant difference in the heart rate, coronary flow or monophasic action potential amplitude between the three groups (P>0.05). Compared with group C, Vmax in the epicardium was significantly decreased, MAPD50 and MAPD90 in the three transmural layers were prolonged, and TDR was prolonged in group I/R (P 0.05). Conclusion Hydromorphone postconditioning is helpful in maintaining the electrophysiological stability during I/R in isolated rat hearts. Key words: Hydromorphone; Myocardial reperfusion injury; Cardiac electrophysiology; Ischemic postconditioning

Reperfusion facilitates reversible disruption of the human blood-brain barrier following acute ischaemic stroke.

We aimed to detect early changes of the blood-brain barrier permeability (BBBP) in acute ischaemic stroke (AIS), with or without reperfusion, and find out whether BBBP can predict clinical outcomes. Consecutive AIS patients imaged with computed tomographic perfusion (CTP) before and 24 h after treatment were included. The relative permeability-surface area product (rPS) was calculated within the hypoperfused region (rPShypo-i), non-hypoperfused region of ischaemic hemisphere (rPSnonhypo-i) and their contralateral mirror regions (rPShypo-c and rPSnonhypo-c). The changes of rPS were analysed using analysis of variance (ANOVA) with repeated measures. Logistic regression was used to identify independent predictors of unfavourable outcome. Fifty-six patients were included in the analysis, median age was 76 (IQR 62-81) years and 28 (50%) were female. From baseline to 24 h after treatment, rPShypo-i, rPSnonhypo-i and rPShypo-c all decreased significantly. The decreases in rPShypo-i and rPShypo-c were larger in the reperfusion group than non-reperfusion group. The rPShypo-i at follow-up was a predictor for unfavourable outcome (OR 1.131; 95% CI 1.018-1.256; P = 0.022). Early disruption of BBB in AIS is reversible, particularly when greater reperfusion is achieved. Elevated BBBP at 24 h after treatment, not the pretreatment BBBP, predicts unfavourable outcome. • Early disruption of blood-brain barrier (BBB) in stroke is reversible after treatment. • The reversibility of BBB permeability is associated with reperfusion. • Unfavourable outcome is associated with BBB permeability at 24 h after treatment. • Contralateral non-ischaemic hemisphere is not 'normal' during an acute stroke.

Role of p38 mitogen activated protein kinase signaling pathway in lung ischemia-reperfusion protection offered by HOE642

To explore the protective effect of sodium channels antagonists HOE642 on lung ischemia reperfusion and the role of the p38 mitogen activated protein kinase (p38MAPK) signaling pathway in this process. Methods: A total of 36 mice were randomly divided into a sham operation group (SHAM group), a lung ischemia reperfusion group (I/R group) and a lung ischemia reperfusion+HOE642 group (HOE group). The water content was detected by electronic scales, and the lung tissue pathological changes were observed under optical microscope. The inflammatory cytokines including IL-6 and TNF-α were examined by ELISA. The intracellular calcium fluorescence intensity was examined and observed under fluorescence microscope, and the protein expression of p38MAPK was detected by Western blot. Results: Lung water content in the HOE group was lower than that in the I/R group, but higher than that in the SHAM group (both P<0.05). Lung interstitial edema, hemorrhage, lung tissue inflammatory cells infiltration were significantly alleviated in the HOE group than those in the I/R group, while the injury in the HOE group was aggravated than those in the SHAM group (both P<0.05). The IL-6 and TNF-α in lung tissues in the HOE group were lower than those in the I/R group, but higher than those in the SHAM group (both P<0.05). Intracellular calcium fluorescence intensity in the HOE group was lower than that in the I/R group, but higher than that in the SHAM group (both P<0.05). The protein expression of p38MAPK in lung tissues in the HOE group was lower than that in the I/R group, but higher than that in the SHAM group (both P<0.05). Conclusion: HOE642 may exert protective effect on pulmonary I/R injury through regulation of the p38MAPK signaling pathway, resulting in reduction of intracellular calcium ion concentration and calcium overload, and decrease of inflammatory response.

Effects of Sildenafil and Tadalafil on Edema and Reactive Oxygen Species Production in an Experimental Model of Lung Ischemia-Reperfusion Injury

BackgroundLung ischemia-reperfusion injury is characterized by formation of reactive oxygen species and cellular swelling leading to pulmonary edema and primary graft dysfunction. Phosphodiesterase 5 inhibitors could ameliorate lung ischemia-reperfusion injury by interfering in many molecular pathways. The aim of this work was to evaluate and compare the effects of sildenafil and tadalafil on edema and reactive oxygen species formation in an ex vivo nonhuman animal model of lung ischemia-reperfusion injury. MethodsThirty-two Wistar rats were distributed, treated, perfused and the cardiopulmonary blocks were managed as follows: control group: immediate excision and reperfusion without pretreatment; ischemia reperfusion group: treatment with dimethylsulfoxide 0.9% and excision 1 hour later; sildenafil group: treatment with sildenafil (0.7 mg/kg) and excision 1 hour later; and tadalafil group: treatment with tadalafil (0.15 mg/kg) and excision 2 hours later. All cardiopulmonary blocks except control group were preserved for 8 hours and then reperfused. Pulmonary arterial pressure, pulmonary venous pressure, and capillary filtration coefficient were measured. Reactive oxygen species were measured. ResultsEdema was similar between control and sildenafil groups, but significantly greater in the ischemia-reperfusion (P ≤ .04) and tadalafil (P ≤ .003) groups compared with the sildenafil group. The malondialdehyde levels were significantly lower in the sildenafil (P ≤ .001) and tadalafil (P ≤ .001) groups than the ischemia-reperfusion group. ConclusionsAdministration of sildenafil, but not tadalafil, decreased edema in lung ischemia-reperfusion injury. Both drugs decreased reactive oxygen species formation in a lung ischemia-reperfusion injury model.

Suppression of TLR4/NF-κB Signaling Pathway Improves Cerebral Ischemia-Reperfusion Injury in Rats.

The present study aimed to investigate the effects of the toll-like receptor 4 (TLR4)/nuclear factor-kappaB (NF-ҡB) signaling pathway in cerebral ischemia-reperfusion injury. A total of 125 male Sprague Dawley (SD) rats were selected for this study. Fifty SD rats were randomly divided into the control, sham injury, 0.5h perfusion, 2h perfusion, and 6h perfusion groups to establish the model of ischemia-reperfusion. The rat brain injury model was established using the other 75 male SD rats, and different model groups with different treatments were established (15 rats per group): model control group (injected with 10μL of saline solution), model + TAK-242 group (injected with resatorvid), model + PDTC group (injected with pyrrolidine dithiocarbamate), model + LPS group (injected with lipopolysaccharide), and sham injury group (incision to the neck skin and injected with 10μL of saline solution for normal rats). These five groups were further assigned into three subgroups: day 3 group, day 7 group, and day 21 group. To determine how the TLR4/NF-қB signal pathway affects cerebral ischemia-reperfusion injuries, various methods including the Morris water maze, triphenyl tetrazolium chloride (TTC) staining, hematoxylin-eosin (HE) staining, and western blotting were employed in this study. No neurological deficit was observed in rats from the model control and sham injury groups. A slight neurological deficit was found in the 0.5h reperfusion group, while in the 2 and 6h perfusion groups, neurological dysfunction was evident. Compared to the sham injury group, the model control group displayed a longer escape latency (EL) and increased cerebral infarction volume and pathological changes with enhanced expression of TLR4 and NF-κB (all P<0.05). The inhibition of the TLR4/NF-κB signal pathway shortened rat EL and diminished cerebral infarction volume, and the pathological changes became less evident (all P<0.05), while the activation of the TLR4/NF-κB signal pathway elongated rat EL, enlarged infarction volume, and increased cerebral pathological change (all P<0.05). Pearson correlation analysis demonstrated that TLR4/NF-κB expression is correlated with the extent of rat brain damage. Cerebral ischemia-reperfusion injury in rats can be alleviated via the inhibition of the TLR4/NF-κB signaling pathway.

The effect of the antioxidant drug U-74389G on urea levels during ischemia reperfusion injury in rats

This experimental study examined the effect of the antioxidant drug U-74389G, on a rat model and particularly in a renal ischemia - reperfusion protocol. The effects of that molecule were studied biochemically using blood mean urea levels. Forty rats of mean weight 231.875 g were used in the study. Urea levels were measured at 60 min of reperfusion (groups A and C) and at 120 min of reperfusion (groups B and D). The drug U-74389G was administered only in groups C and D. U-74389G administration significantly decreased the predicted urea levels by 11.35%+2.73% (P=0.0001). Reperfusion time non-significantly increased the predicted urea levels by 2.26%+3.29% (P=0.4103). However, U-74389G administration and reperfusion time together significantly decreased the predicted urea levels by 6.31%+1.70% (P=0.0005). U-74389G administration whether it interacted or not with reperfusion time has significant decreasing effect on the urea serum levels, reflecting a respective renal function augmentation.

Neutralizing IL-6 reduces heart injury by decreasing nerve growth factor precursor in the heart and hypothalamus during rat cardiopulmonary bypass

AimsTo investigate whether the expression of nerve growth factor precursor (proNGF) changes during cardiopulmonary bypass (CPB) and whether neutralizing interleukin-6 (IL-6) during CPB has cardiac benefits. Main methodsThirty patients undergoing CPB were recruited and their serum proNGF and troponin-I (TNI) were detected. In addition, rats were divided into three groups: CPB group, CPB with cardiac ischemia–reperfusion (IR) group, and a control group. The pre-CPB standard deviation of N-N intervals (SDNN) and post-CPB SDNN were compared. At the end of CPB, nerve peptide Y (NPY), acetylcholinesterase, cell apoptosis, and proNGF protein expression were measured in the heart and hypothalamus. Another rat cohort undergoing CPB was divided into two groups: an anti-IL-6 group with IL-6 antibody and a control group with phosphate buffer solution. At the end of CPB, serum hs-troponin-T and cardiac caspases 3 and 9 were detected. NPY and proNGF in the heart and hypothalamus were detected. Key findingsIn patients, serum proNGF increased during CPB, and the concentration was positively correlated with TNI. In rats, cardiac autonomic nervous function was disturbed during CPB. More apoptotic cells and higher levels of proNGF were found in the heart and hypothalamus in the CPB groups than in the control groups. Neutralizing IL-6 was beneficial to lower cardiac injury by decreasing proNGF and apoptosis. SignificanceCPB induced changes in proNGF in the heart and hypothalamus. Suppressing inflammation attenuated myocardial apoptosis and autonomic nerve function disturbance in CPB rats, likely due in part to regulation of proNGF in the heart and hypothalamus.

MP74-07 RENAL PROTECTION BY APPLYING ISCHEMIC PRECONDITIONING.

MP74-07 RENAL PROTECTION BY APPLYING ISCHEMIC PRECONDITIONING.

Effect of electroacupuncture on gene expression in calcium signaling pathway in hippocampal cells in mice with cerebral ischemia reperfusion

ObjectiveTo observe the regulation of electroacupuncture on gene expression at calcium signaling pathways in mice with cerebral ischemia reperfusion. MethodsSixty male, inbred Kunming mice were randomly assigned to three groups: repeated cerebral ischemia reperfusion group (RG, n = 24), sham-operated group (SG, n = 12), and electroacupuncture group (EG, n = 24). Mice in RG and EG groups were modeled by repeated cerebral ischemia reperfusion surgery, and EG mice were treated with electroacupuncture for 30 min after recovery from anesthesia. Changes in gene expression profile of mice hippocampi were analyzed by global expression profile microarray. Genes that were up-regulated or down-regulated greater than 1.5 folds were considered to be biologically meaningful. Real-time quantitative polymerase chain reaction (q-PCR) method was used to verify the expression of selected genes based on the algorithm [2^ (‡‡Ct)]. ResultsCompared with SG mice, 242 genes showed different in expressions in RG mice: 107 down-regulated and 135 up-regulated. Compared with RG mice, 609 genes showed a difference of expression in EG mice: 315 down-regulated and 375 up-regulated. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated two pathways: calcium signaling and long-term potentiation in which 11 differentially expressed genes selected. Six of the 11 genes in the calcium signaling pathway were verified after real-time q-PCR testing. ConclusionElectroacupuncture treatment of cerebral ischemia reperfusion appears to regulate Atp2a2, Cacna1e, Camk2a, Gnas, Grm1, Rapgef3 genes in the calcium signaling pathway.

Tacrolimus pretreatment on liver ischemia reperfusion injury in rats

Objective To determine the effects of tacrolimus (FK506) pretreatment on the liver ischemia reperfusion (IR) injury. Methods 32 mature SD rats were randomly assigned into four groups, which were sham-operated group (S), ischemia reperfusion group (IR), low-dose FK506-treated group (L) and high-dose FK506-treated group (H). After the treatment of liver ischemia for 60 minutes and reperfusion for 6 hours, the levels of serum ALT and AST in rats were tested. The TNF-α and IL-1β levels were evaluated by enzyme linked immunosorbent assay. Liver damage was assessed by paraffin sections stained with H&E. The quantitative real-time PCR, the immunohistochemistry and Western blot were used to detect the expression of HMGB1 mRNA and protein with or without FK506 pretreatment. Results The levels of serum ALT [(424.0±137.4)U/L, (291.0±42.0)U/L], AST [(554.2±127.7)U/L, (410.2±7.0)U/L], TNF-α [(115.1±49.0) ng/L, 120.4±28.5) ng/L] and IL-1β [(424.5±105.2) ng/L, (612.1±49.6) ng/L] decreased markedly in the group L and group H compared with the group IR (P 0.05). Conclusion FK506 pretreatment can protect the liver by reducing the expression of HMGB1, inhibiting the release of inflammatory cytokines and alleviating cell necrosis after the liver ischemia reperfusion injury in rats. Key words: Tacrolimus; Liver; Ischemia reperfusion; High mobility group box 1 protein, HMGB1; Liver protection

Relationship between endoplasmic reticulum stress and cell apoptosis during liver cold ischemia-reperfusion in rats

Objective To evaluate the relationship between endoplasmic reticulum stress and cell apoptosis during liver cold ischemia-reperfusion(I/R)in rats. Methods Thirty-two SPF healthy adult male Sprague-Dawley rats, weighing 200-250 g, were divided into 2 groups(n=16 each)using a random number table: sham operation group(group S)and liver cold I/R group(group I/R). In group I/R, the liver was perfused through the portal vein with 4 ℃ lactated Ringer's solution 6-8 ml/min for 30 min after liver ischemia, and the liver blood flow was restored after the end of perfusion. At 6 h of reperfusion in group I/R or at 6 h after peritoneum closure in group S, blood samples from the inferior vena cava were collected for determination of serum alanine transaminase and aspartate transaminase concentrations. After blood sampling, liver tissues were obtained for examination of pathological changes and for determination of malondialdehyde content(by thiobarbituric acid method), superoxide dismutase activity(using xanthine oxidase method), cell apoptosis(using TUNEL), expression of endoplasmic reticulum protein 46(ERP46), immunoglobulin heavy chain binding protein(BiP)and caspase-12(by immunohistochemistry), and expression of ERP46, BiP and caspase-12 mRNA(using quantitative real-time polymerase chain reaction). The pathological changes were scored. Apoptosis rate was calculated. Results Compared with group S, the serum alanine transaminase and aspartate transaminase concentrations, pathological scores, malondialdehyde content and apoptosis rate were significantly increased, the activity of superoxide dismutase was decreased, and the expression of ERP46, BiP and caspase-12 protein and mRNA was up-regulated in group I/R(P<0.05). Conclusion The mechanism of cell apoptosis during liver cold I/R may be related to excessive activation of endoplasmic reticulum stress in rats. Key words: Endoplasmic reticulum; Stress; Reperfusion injury; Liver transplantation