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.
Objective To explore the impact of ischemic postconditioning on ischemia-reperfusion injury in isolatedelderly rat hearts and their relation with P-Akt. Methods A total of 30 healthy elderly SD rats (21-23 months old， male or female) with their body weight of 450-500 g were divided into 3 groups: control group， ischemia-reperfusion group， and postconditioning group， with 10 rats in each group. Coronary artery blood flow，myocardial infarction size， phosphorylatedAkt （p-Akt） expression， and changes in myocardium and mitochondria were detected. Results Coronary artery blood flow of the postconditioning group was significantly higher than that of the ischemia-reperfusion group （6.4±1.2 ml/min vs.3.1±1.2 ml/min， P＜0. 01）， and myocardial infarction size of the postconditioning group was significantly smaller thanthat of the ischemia-reperfusion group （35.0%±2.0% vs. 55.7%±3.6%， Plt;0. 05）. The expression of P-Akt was significantlyhigher， and myocardial fibers and mitochondria were preserved better in the postconditioning group than the ischemia-reperfusion group. Conclusion Ischemic postconditioning can protect isolated elderly rat hearts against ischemia-reperfusion injury， which may be related to P-Akt activation.
Abstract： Ischemia postconditioning is a new concept based on ischemic preconditioning. It has become a hot topic in protection of ischemic-reperfusion injury because of its effective protection, relative ease of application, and postconditioning. However, its precise mechanisms and most effective application methods are still unclear. This review covers recent progress in the understanding, developments (in remote postconditioning and pharmacological postconditioning), applications to the protection of heart, lung, liver, kidney, and brain, mechanisms and appropriate protocol of ischemic post-conditioning.
Abstract： Objective To observe the expression changes of microRNA 1 （miRNA-1） and microRNA 21（miRNA-21） after ischemic preconditioning （IPC）, ischemic postconditioning （IPO） and remote ischemic preconditioning （RIPC）in an ischemia-reperfusion rat heart model in vitro, as well as the expression of their target protein heat shock protein 70 （HSP70） and programmed cell death 4 （PDCD4）, and evaluate whether miRNA are involved in endogenous cardio-protective mechanism. Methods The Langendorff-perfused Sprague-Dawley rat hearts were randomly assigned into one of the four groups, control group （CON group, n=12）, ischemia preconditioning group （IPC group， n=12） , ischemia postconditioning group （IPO group， n=12） and remote ischemia preconditioning group （RIPC group，n=12）. Cardiac function was digitalized and analyzed. The expression of HSP70, PDCD4, B-cell lymphoma/leukemia-2 （Bcl-2） and Bax was detected by Western blotting. The expression of miRNA-1 and miRNA-21 was detected by real-time reverse transcriotion-polymerase chain reaction （RT-PCR）. Assessment of cardiac infarct size and myocardial apoptosis was determined using triphenyltetrazolium chloride （TTC） assay and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay （TUNEL） assay respectively. Results The expressions of miRNA-1 and miRNA-21 were up-regulated in IPC group, but the expression of miRNA-1 was down-regulated in RIPC group and IPO group （P＜0.05）. The expressionsof PDCD4, HSP70 and Bax were down-regulated in ‘conditioning’ groups compared with CON group （P＜0.05）. The expression of Bcl-2 was not statistically different among the four groups. The infarct size and the myocardial apoptosis in ‘conditioning’ hearts were significantly decreased compared with CON group （P＜0.05）. Conclusion The expressions of the miRNA-1 and miRNA-21 are different in IPC, RIPC and IPO groups, and their target proteins are not inversely correlated with the miRNAs in all the ‘conditioning’ groups.
ObjectivesTo explore the mechanisms by which ischmic preconditioning (IPC), ischemic postconditioning (IPO) and IPCIPO exert influence on ischemic reperfusion injury (IRI) of the graft of SD rat after pancreas transplantation. MethodsAfter the establishment of diabetic SD rats model by using streptozotocin, 24 rats suffered from pancreas transplantation and were randomly averagely divided into four groups: I/R group, IPC group, IPO group, and IPC-IPO group. Six diabetic SD rats suffered with sham operation were served as SO group. The blood glucose level of rats in each group was detected before and after reperfusion, the contents of malonaldehyde (MDA) and super oxide dismutase (SOD) of pancreas allograft were tested at 2 h after reperfusion, and the apoptosis index (AI) of pancreas allograft was monitored by using TUNEL method. ResultsThe blood glucose level of rats in each group was not significantly different (Pgt;0.05). In SO group, the blood glucose level of rats was significantly higher than other groups (Plt;0.01). The blood glucose levels of rats after reperfusion decreased from the levels before reperfusion in I/R group, IPC group, IPO group, and IPC-IPO group (Plt;0.05 or Plt;0.01), furthermore the blood glucose level of rats in I/R group was significantly higher than that in abovementioned three groups (Plt;0.01), although among which the difference was not markedly (Pgt;0.05). When compared with I/R group, the MDA contents of rats after reperfusion in IPC group, IPO group， and IPC-IPO group decreased (Plt;0.01), while the SOD contents of rats after reperfusion increased (Plt;0.01). In rats of SO group, the MDA and SOD contents were significantly higher and lower than other groups, respectively (Plt;0.01). The MDA and SOD contents in IPC group, IPO group, and IPC-IPO group were not different (Pgt;0.05). The AI of pancreas allograft at 2 h after reperfusion in I/R group 〔(47.31±4.52)%〕, IPC group 〔(26.25±3.17)%〕, IPO group 〔(24.73±3.62)%〕, and IPC-IPO group 〔(25.5±4.15)%〕 were higher than that in SO group 〔(3.16±0.53)%〕, Plt;0.01. The AI of pancreas allograft in IPC group, IPO group, and IPC-IPO group were not different (Pgt;0.05), but they were lower than that in I/R group (Plt;0.01). Pathological results showed that injury of pancreas allograft in I/R group was most severe. ConclusionsIPO and IPC are associated with comparable effectiveness to protect graft from IRI during pancreas transplantation. The combined protective effects of IPC and IPO do not appear to be additive, which is equal to IPC or IPO alone.