ObjectiveTo study the changes of levels of α subunits of stimulatory (Gsα) and inhibitory guanine nucleotide binding protein (Giα) in newborn guinea pig (0 2 days old) myocardium undergoing global ischemic reperfusion, and influences on the changes by St.Thomas Ⅱ and cold blood cardioplegic solution.MethodsThirty newborn guinea pigs were randomly assigned to three groups. GroupⅠ ( n = 10): the newborn hearts suffered by hypothermic global ischemia; group Ⅱ( n =10): the newborn hearts arrested by St. Thomas Ⅱ , and group Ⅲ ( n = 10): the newborn hearts arrested by cold blood cardioplegic solution. Levels of Gsα and Giα were investigated with Western blot analysis.ResultsNo differences of levels of Gsα and Giα were found in three groups before ischemia ( P gt;0.05). The level of Gsα after ischemia was significantly decreased than before ischemia in groupⅠand group Ⅱ ( P lt; 0 01), whereas no pronounced changes in group Ⅲ ( P gt;0.05) were noted after ischemia. The level of Gsα in group Ⅲ was not significantly changed after reperfusion compared with before ischemia( P gt;0 05), and it was much higher than those in groupⅠand group Ⅱ ( P lt; 0 01). Level of Giα was found not markedly changed in group Ⅲ after reperfusion compared with that before ischemia, but was notable higher in groupⅠand group Ⅱ( P lt;0.01). ConclusionsSignificant decrease of level of Gsα, whereas marked increase of level of Giα are found in myocardium of newborn guinea pig undergoing hypothermic (20℃) ischemic reperfusion. No impact of St. Thomas Ⅱ on these changes is verified, but recovery to the level of Gsα and Giα before ischemia is achieved by cold blood cardioplegic solution after ischemia and reperfusion. Unbalance between Gsα and Giα is the one of the mechanisms of ischemic reperfusion injury for immature myocardium.
目的 探讨异氟醚通过抑制细胞间黏附分子（ICAM-1）表达参与减轻肝脏缺血-再灌注（IR）损伤的可能调节机制。 方法 32只雌性SD大鼠分为4组。A组大鼠行腹腔注射1%戊巴比妥钠40 mg/kg麻醉，进行手术但不阻断入肝血流；B组1%戊巴比妥钠麻醉后行部分肝脏IR；C组大鼠仅接受1.0 MAC异氟醚吸入麻醉，不阻断血流；D组采用1.0 MAC异氟醚麻醉，建立肝脏IR模型。肝脏缺血60 min，再灌注3 h后取肝组织和血液标本，检测血清丙氨酸转氨酶（ALT）和天冬门氨酸转氨酶（AST）、肝组织ICAM-1和肝组织还原型谷胱甘肽（GSH）、脂质过氧化物丙二醛（MDA）和超氧化物歧化酶（SOD）含量。 结果 与戊巴比妥钠麻醉比较，采用异氟醚处理后明显降低血清ALT和AST的水平，再灌注肝组织内GSH、SOD含量明显高于而MDA含量降低，同时抑制肝组织ICAM-1的表达。 结论 异氟醚麻醉能够有效减轻肝脏IR损伤，抑制氧自由基的生成和释放，具体机制可能与抑制ICAM-1表达致使细胞内GSH含量增加密切相关。
【Abstract】 Objective To investigate the effect of verapamil on apoptosis, calcium and expressions of bcl-2 and c-myc of pancreatic cells in ischemia-reperfusion rat model. Methods Wistar rats were randomly divided into three groups: control group （n=10）; ischemia-reperfusion group （n=10）; verapamil treatment group （n=10）. The anterior mesenteric artery and the celiac artery of rats in both ischemia-reperfusion group and verapamil treatment group were occluded for 15 min followed by 12-hour reperfusion. Verapamil （1 mg／kg） was injected via caudal vein to the rats in verapamil treatment group 15 min before occlusion and 1 hour after the initiation of reperfusion, respectively; and ischemia-reperfusion group was given the same volume of salient twice intravenously. Pancreatic tissues were collected from the dead rats after twelve hours since the reperfusion. The pathologic characters of pancreatic tissue were observed under light microscope; The level of calcium in the tissue was measured by atomic absorption spectrometer; TUNEL was used to detect apoptosis of pancreatic cells; and the expressions of c-myc and bcl-2 in the cells were also analyzed by immunohistochemistry technique and flow cytometry. Results The pathologic change in verapamil treatment group was less conspicuous than that of ischemia-reperfusion group. Both the calcium level and the number of apoptotic cells in verapamil treatment group were less than those of ischemia-reperfusion group 〔（411.1±55.8） μg/g dry weight vs （470.9±31.9） μg/g dry weight, P＜0.05 and （9.5±2.9）% vs （18.4±3.1）% 〕, P＜0.05. After taking verapamil, the number of apoptotic cells decreased, whereas the expressions of bcl-2 and c-myc increased. The fluorescent indexes of bcl-2 and c-myc in verapamil treatment group were significantly higher than those of ischemia-reperfusion group (1.72±0.11 vs 1.41±0.07, P＜0.05; 1.76±0.19 vs 1.55±0.13, P＜0.05. Conclusion Ischemia-reperfusion injury can induce apoptosis of pancreatic cells. Verapamil could protect the injured pancreatic tissue by reducing the level of calcium, stimulating the expressions of bcl-2 and c-myc and inhibiting apoptosis of pancreatic cells.
ObjectiveTo summarize the mechanism of neutrophil extracellular traps (NETs) in hepatic ischemia-reperfusion injury (HIRI) and the research progress in targeting NETs to reduce HIRI, providing valuable reference for reducing HIRI. MethodThe related literatures at home and abroad about the role of NETs in the pathogenesis of HIRI and target NETs to alleviate HIRI were retrieved and reviewed. ResultsHIRI usually appeared in the process of liver surgery and was a common clinical problem, which occured in situations such as liver surgery, organ transplantation, liver ischemia and so on. This kind of injury would lead to tissue necrosis, inflammatory response and oxidative stress, which was a major cause of hepatic dysfunction and multiple organ failure after hepatic surgery, greatly increases the complications and mortality after hepatic surgery. NETs played a crucial role in the aseptic inflammatory response induced by hepatic ischemia/reperfusion. During hepatic ischemia-reperfusion, neutrophils promoted inflammatory cascade reactions and cytokine storms by forming NETs, exacerbating damage caused by hepatic ischemia-reperfusion. At present, some experimental and clinical studies had shown that inhibiting the formation of NETs or eliminating the formed NETs could alleviate the hepatic ischemia-reperfusion injury and improve the prognosis. ConclusionsTargeting NETs may become a new method for treating hepatic ischemia-reperfusion injury. In the future, it is foreseeable that more experiments and clinical trials will be conducted on targeted NETs for the treatment of hepatic ischemia-reperfusion injury. And gradually establish more comprehensive and effective treatment strategies, thereby providing new ways to improve the prognosis of hepatic surgery patients in clinical practice.
【Abstract】ObjectiveTo investigate the effect of ischemia-reperfusion （I/R） injury on apoptosis of pancreatic cells in rats with acute pancreatitis(AP). MethodsFifty-four SD rats were randomized into 3 groups: pancreatitis group (n=24), I/R-injury group (n=24) and control group (n=6). The animal model of AP was induced by retrograde injection of 3% sodium taurocholate into biliopancreatic duct in rats. Pancreatic I/R was caused by blocking the inferior splenic artery and removing the clamp after AP induction. At 1 h, 3 h, 6 h and 12 h, groups of rats were sacrificed. A terminal deoxynucleotidyl transferase-mediated dUTP-biotion nick end labeling (TUNEL) was used to detect pancreatic apoptosis, and histological changes of the pancreas were observed. ResultsPancreatic hemorrhage, necrosis were respectively observed in the pancreatitis rats at 6 h and the I/R-injury rats at 1 h. Histological changes of the pancreatitis rats at 1 h and 3 h were only congestion and edema. Apoptoic acinar cells increased after AP induction, the peak respectively appeared at 6 h in the pancreatitis rats and at 3 h in the I/R-injury rats. Compared with the pancreatitis rats, apoptosis index (AI) of the I/Rinjury rats was significantly higher at 1 h and 3 h (P＜0.01, P＜0.05, respectively), but lower at 6 h and 12 h (P＜0.05, P＜0.01, respectively). ConclusionI/R injury can induce conversion of edematous pancreatitis to hemorrhagic necrotizing pancreatitis and apoptosis of acinar cells. Apoptosis may be a beneficial response to pancreatic injury in AP.
Objective To investigate the effects of ischemic postconditioning （IPO） on inflammatory response inischemia-reperfusion （IR） injury of rat lungs in vivo. Methods Forty SD rats were randomly divided into 5 groups inclu-ding a sham surgery group （S group），a 30-minute IR group （I/R-30 group），a 120-minute IR group（IR-120 group），a 30-minute IPO group （IPO-30 group），and a 120-minute IPO group （IPO-120 group）. There were 8 rats in each group. All therats received left thoracotomy after anesthesia. In the sham surgery group，a line was only placed around the left hilum butnot fastened. In the I/R-30 group and I/R-120 group，a line was fastened to block the blood flow of the left lung for 1 hour，then loosened for reperfusion for 30 minutes and 120 minutes respectively. In the IPO-30 group and IPO-120 group，afterblocking the blood flow of the left lung for 1 hour，the left hilum was fastened for 10 seconds and loosened for 10 seconds（repeating 3 times for 1 minute），then the line was loosened for 30 minutes and 120 minutes respectively. The levels of interleukin-10 （IL-10） in lung tissues and soluble intercellular adhesion molecule-1 （sICAM-1） in plasma were measured. Histopathological changes of lung tissues were observed and diffuse alveolar damage （DAD） scores was calculated.Results The levels of plasma sICAM-1 in the I/R-30 group and I/R-120 group were significantly higher than that of S group ［（2.140±0.250）μg/L vs. （0.944±0.188）μg/L，P=0.003；（2.191±0.230）μg/L vs. （0.944±0.188）μg/L，P=0.003］. IL-10levels in lung tissues in the I/R-30group and I/R-120 group were also significantly higher than that of S group［（15.922±0.606）pg/mg pro vs. （7.261±0.877）pg/mg pro，P=0.037；（17.421±1.232）pg/mg pro vs. （7.261±0.877）pg/mg pro，P=0.042］. Pathologic lesions of lung tissues in the I/R-30 group and I/R-120 group were more severe than that of S group. After IPO, plasma sICAM-1 levels in the IPO-30 group and IPO-120 group were significantly lower than those in the I/R-30group and I/R-120 group respectively ［（1.501±0.188）μg/L vs.（2.140±0.250）μg/L，P=0.038；（1.350±0.295）μg/L vs.（2.191±0.230）μg/L，P=0.005］. IL-10 levels in lung tissues in the IPO-30 group and IPO-120 group were significantly higherthan those in the I/R-30 group and I/R-120 group respectively ［（20.950±1.673）pg/mg pro vs.（15.922±0.606）pg/mgpro，P=0.008；（25.334±1.173）pg/mg pro vs.（17.421±1.232）pg/mg pro，P=0.006］. DAD scores in the IPO-30 group andIPO-120 group were significantly lower than those in the I/R-30 group and I/R-120 group respectively ［6.8±1.4 vs. 11.5±1.9，P=0.007；7.5±1.6 vs. 13.2±1.7，P=0.005］. Pathological lesions of the lung tissues of IPO groups were less severe than those of I/R groups. Conclusion IPO can attenuate IR injury by inhibiting inflammatory response in rat lungs.
ObjectiveTo investigate whether emulsified isoflurane applied after an ischemic episode induces postconditioning in an ischemia model of myocardial injury and its underlying mechanism. MethodsBetween March and October 2012, using a model of in situ myocardial ischemia and reperfusion injury in rats, cardioprotective effects of emulsified isoflurane were examined by determining infarct size, myocardial damage markers and the concentration of tumor necrosis factor (TNF)-α. ResultsEmulsified isoflurane postconditioning limited infarct size compared with control groups. It increased serum concentrations of superoxide dismutase while decreased malonaldehyde. TNF-α positive cells were also significantly reduced in emulsified isoflurane group compared with control group. Infusion of intralipid had no effect on infarct size or other variables. ConclusionIntravenous administration of emulsified isoflurane after reperfusion protects hearts against reperfusion injury, which may be mediated by the inhibition of cardiac damage markers and the concentration of TNF-α.
Acute lung injury is a kind of common complication after cardiopulmonary bypass. Acute lung injury is attributed to the ischemia-reperfusion injury and systemic inflammatory response syndrome. Several factors common in cardiac surgery with cardiopulmonary bypass may worsen the risk for acute lung injury including atelectasis, transfusion requirement, older age, heart failure, emergency surgery and prolonged duration of bypass. Targets for prevention of acute lung injury include mechanical, surgical and anesthetic interventions that aim to reduce the contact activation, systemic inflammatory response, leukocyte sequestration and hemodilution associated with cardiopulmonary bypass. We aim to review the etiology, risk factors and lung protective strategies for acute lung injury after cardiopulmonary bypass.
ObjectiveTo study the protective effects of ischemia preconditioning (IPC) on cryopreservation injury of rat liver.MethodsThe model of isolated nonrecirculated perfusion rat liver was established. The grafts were treated with IPC in different time (ischemia preconditioning time in IPC1 group was 5 min; the time in IPC2 group was 10 min; while the time in IPC3 group was 15 min). The cryopreservation injury of the grafts in each group was determined and compared. ResultsThe levels of aspartate transaminase (AST) and alanine transaminase (ALT) in the effluent solutions in IPC1 group were (40.1±6.3) U/L and （17.1±0.5） U/L respectively, and IPC2 group (53.6±3.7) U/L, （19.7±0.5） U/L, which were much lower than those of nonpreconditioning (NPC) group 〔(64.5±8.2) U/L, （23.8±3.9） U/L〕 (P＜0.05). Those in IPC1 group was much lower than those in IPC2 group and IPC3 group 〔(63.8±7.2) U/L,（22.8±2.5） U/L〕 (P＜0.05). The level of lactic acid dehydrogenase (LDH) in NPC group (104.3±20.6) U/L, IPC1 group (84.1±19.7) U/L, IPC2 group (90.5±21.1) U/L, and IPC3 group (103.1±18.5) U/L were of no significant difference (Pgt;0.05). The contents of bile product and the hepatocellular contents of ATP in IPC1 group were (53.5±10.2) μl and (6.15±0.65) μmol/g respectively, and IPC2 group (41.5±8.1) μl, (4.77±0.21) μmol/g, which were much higher than those NPC group 〔(22.8±9.7) μl, (2.62±0.34) μmol/g〕 (P＜0.05). Those in IPC1 group were much higher than those in IPC2 group and IPC3 group 〔(27.5±2.8) μl, (2.61±0.29) μmol/g〕 (P＜0.05). The contents of malondialdehyde (MDA) in liver tissue in IPC1 group was (4.36±0.26) nmol/gand IPC2 group (5.51±0.13)