ObjectiveTo analyze the protective mechanism of spinal cord ischemia-reperfusion injury mediated by N-methyl-D-aspartate (NMDA) receptor.MethodsA total of 42 SD rats were randomly assigned to 4 groups: a non-blocking group (n=6), a saline group (n=12), a NMDA receptor blocker K-1024 (25 mg/kg) group (n=12) and a voltage-gated Ca2+ channel blocker nimodipine (0.5 mg/kg) group (n=12). The medications were injected intraperitoneally 30 min before ischemia. The neural function was evaluated. The neuronal histologic change of spinal cord lumbar region, the release of neurotransmitter amino acids and expression of spinal cord neuronal nitric oxide synthase (nNOS) were compared.ResultsAt 8 h after reperfusion, the behavioral score of the K-1024 group was 2.00±0.00 points, which was statistically different from those of the saline group (5.83±0.41 points) and the nimodipine group (5.00±1.00 points, P<0.05). Compared with the saline group and nimodipine group, K-1024 group had more normal motor neurons (P<0.05). There was no significant difference in glutamic acid concentration in each group at 10 min after ischemia (P=0.731). The nNOS protein expression in the K-1024 group was significantly down-regulated compared with the saline group (P<0.01). After 8 h of reperfusion, the expression of nNOS protein in the K-1024 group was significantly up-regulated compared with the saline group (P<0.05).ConclusionK-1024 plays a protective role in spinal cord ischemia by inhibiting NMDA receptor and down-regulating nNOS protein expression; during the reperfusion, K-1024 has a satisfactory protective effect on spinal cord function, structure and biological activity of nerve cells.
Objective To investigate the mechanism of bone morphogenetic protein-4 (BMP4) in promoting the recovery of small intestinal mucosal barrier function during the recovery period of small intestine ischemia-reperfusion (I/R) injury. Methods Twenty-eight C57BL/6J male mice aged 6–8 weeks were randomly selected and assigned to small intestine I/R group (n=24) and sham operation (SO) group (n=4) by random number table method. Small intestine I/R injury models of 24 mice were established, then 4 mice were randomly selected at 6, 12, 24 and 48 h after I/R established modeling and killed to observe the morphological changes of small intestinal mucosa and detect the expression of BMP4 mRNA in the jejunal epithelial cells, the other 8 mice were allocated for the experimental observation at the recovery period of small intestine I/R injury (24 h after I/R was selected as the observation time point of recovery period of small intestine I/R injury according to the pre-experimental results). Twelve mice were randomly divided into I/R-24 h-BMP4 group (recombinant human BMP4 protein was injected intraperitoneally), I/R-24 h-NS (normal saline) group (NS was injected intraperitoneally), and I/R-24 h-blank group (did nothing), 4 mice in each group. Then the small intestinal transmembrane electrical impedance (TER) was measured by Ussing chamber. The expressions of BMP4 protein and tight junction proteins (occludin and ZO-1), Notch signaling pathway proteins (Notch1 and Jagged1), and Smad6 protein were detected by Western blot. Results At 24 h after I/R injury, the injuries of villous epithelium, edema, and a small part of villi were alleviated. The BMP4 mRNA expressions at 6, 12, 24 and 48 h after I/R injury in the small intestinal epithelial cells were increased as compared with the SO group. Compared with the I/R-24 h-NS group and the I/R-24 h-blank group, the TER was increased, and the expression levels of occludin, ZO-1, p-Smad6, Notch1, Jagged1 were increased in the I/R-24 h-BMP4 group. Conclusion From the preliminary results of this study, during recovery period of small intestine I/R injury, the expression of BMP4 in small intestinal epithelial cells is increased, permeability of jejunal mucosal barrier is increased, which might promote the recovery of small intestinal mucosal barrier function by activating the Notch signaling pathway (Notch1 and Jagged1), Smad classic signaling pathway, and promoting the increase of tight junction protein expression (occludin and ZO-1).
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.
Objective To study the effect of p38MAPK activity on tumor necrosis factor-α （TNF-α） mRNA and intercellular adhesion molecule 1 （ICAM1） mRNA expressions of isolated rabbit liver during early stage of cold preservation and reperfusion period. Methods Based on the cold preservation and reperfusion model of isolated rabbit liver, the animals were divided into inhibition group （n=12） with 3 μmol/L SB202190 (p38MAPK specificity inhibitor) in perfusate and control group （n=12） with no SB202190 in perfusate. Liver tissue samples were harvested at the time points of before resection, end of cold preservation, and different reperfusion period (10, 30, 60 and 120 min). Protein expression and activity of p38MAPK were detected by Western blot and immunoprecipitation respectively, expression of TNF-α mRNA was detected by RT-PCR, and expression of ICAM1 mRNA was detected by in situ hybridization. Results There was no obvious change of expression of p38MAPK protein in liver tissue both in two groups during the total period （P＞0.05）， and there was no statistically significant difference between two groups （P＞0.05）. At time points of end of cold preservation, 10, 30 and 60 min of reperfusion, the activity of p38MAPK in control group was significantly higher than that at the time points of before resection and 120 min of reperfusion (P＜0.01), and was also significantly higher than that in inhibition group at the same time points (P＜0.01). There was no significant difference in activity of p38MAPK among all time points in inhibition group (P＞0.05). The expressions of TNF-α mRNA and ICAM1 mRNA at the time points of before resection, end of cold preservation, and 10 and 30 min of reperfusion were significantly lower than those in 60 and 120 min of reperfusion in both two groups (P＜0.05, P＜0.01); The expressions of TNF-α mRNA and ICAM1 mRNA in inhibition group were significantly lower than those in control group at the time points of 60 and 120 min of reperfusion (P＜0.01). The activity of p38MAPK of liver tissue during cold preservation and reperfusion period was significantly correlated with the level of TNF-α mRNA and level of ICAM1 mRNA expression （r=0.996, P＜0.01； r=0.985, P＜0.01）. Conclusions These results suggest that p38MAPK pathway may regulate the expressions of TNF-α and ICAM1 at the level of transcription and the activation of p38MAPK can up-regulate TNF-α and ICAM1 expressions, which may be one of the important mechanisms to cause ischemia-reperfusion injury of isolated liver during cold preservation and reperfusion period.
Objective
To investigate the targeted combination and anti-inflammatory effects of anti-intercellular adhesion molecule 1 (ICAM-1) targeted perfluorooctylbromide (PFOB) particles on myocardial ischemia-reperfusion injury in rat model.
Methods
Seventy-six adult Sprague Dawley rats (male or female, weighing 250-300 g) were selected for experiment. The models of myocardial ischemia-reperfusion injury were established by ligating the left anterior descending coronary artery for 30 minutes in 30 rats. The expression of ICAM-1 protein was detected by immunohistochemistry staining at 6 hours after reperfusion, and the normal myocardium of 10 rats were harvested as control; then the content of interleukin 8 (IL-8) in serum was tested every 6 hours from 6 hours to 48 hours after reperfusion. The other 36 rats were randomly divided into 6 groups (n=6): ischemia-reperfusion injury model/targeted PFOB particles group (group A), ischemia-reperfusion injury model/untargeted PFOB group (group B), normal control/targeted PFOB particles group (group C), normal control/untargeted PFOB particles group (group D), ischemia-reperfusion injury model/normal saline group (group E), and sham operation group (group F). The ischemia-reperfusion injury models were established in groups A, B, and E; while a thread crossed under the coronary artery, which was not ligated after open-chest in group F. After 6 hours of reperfusion, 1 mL of corresponding PFOB particles was injected through juglar vein in groups A, B, C, and D, while 1 mL of nomal saline was injected in group E. Ultrasonography was performed in groups A, B, C, and D before and after injection. The targeted combination was tested by fluorescence microscope. The content of IL-8 was tested after 6 and 24 hours of reperfusion by liquid chip technology in groups A, B, E, and F.
Results
After 6 hours of reperfusion, the expression of ICAM-1 protein significantly increased in the anterior septum and left ventricular anterior wall of the rat model. The content of IL-8 rised markedly from 6 hours after reperfusion, and reached the peak at 24 hours. Ultrasonography observation showed no specific acoustic enhancement after injection of PFOB particles in groups A, B, C, and D. Targeted combination was observed in the anterior septum and left ventricular anterior wall in group A, but no targeted combination in groups B, C, and D. There was no significant difference in the content of IL-8 among groups A, B, and E after 6 hours of reperfusion (P gt; 0.05), but the content in groups A, B, and E was significantly higher than that in group F (P lt; 0.05). After 24 hours of reperfusion, no sigificant difference was found in the content of IL-8 between groups A and B (P gt; 0.05), but the content of IL-8 in groups A and B were significantly lower than that in group E (P lt; 0.05).
Conclusion
Anti-ICAM-1 targeted PFOB particles can target to bind and pretect injured myocardium of rat by its anti-inflammation effects.
Objective To investigate the maximum tolerance limit of rats to hepatic inflow occlusion with portal vein blood bypss (PBB) in normothermia. Methods First. A new animal model was established, the animal survival rate were calculated following 7 days of reperfusion after hepatic inflow occlusion of 30, 60, 90, 100, 110, 120 min or portal triad clamping (PTC) of 30 min. And then, the hepatic energy metabolism (RCR, P/O, ATP, AKBR) was studied following 30, 90, 120 min of ischemia or 1, 6, and 24 hours of reperfusion after the ischemia. According to the reversibility of the hepatic motochondrial function injury and maximum as long as a period of liver warm ischemia of all animal postoperative 7 days survial, the safe limit of rat to hepatic inflow occlusion was evaluated. Results The survival rate on postoperative 7 days was one hundred percent subjected to 30, 60 and 90 min of hepatic inflow occlusion, and 50, 30, 20 percent in 100, 110, 120 min, respectively, the survival rate in rats with 30 min of portal triad champing was about 40 percent. The parameters of hepatic motochondrial function reflecting the degree of liver damage to ischemia showed significantly different as compared to sham group. The functional lesion was exacerbated during inital reperfusion, then was restored progressively in PBB-30 min and PBB-90 min groups, but was maintained low level in PBB-120 min and PTC-30 min groups.Conclusion The 90 minutes is the maximum limit of rats to hepatic inflow occlusion in normothermia.
ObjectiveTo explore performances of functional magnetic resonance imaging (MRI) in evaluation of hepatic warm ischemia-reperfusion injury.MethodThe relative references about the principle of functional MRI and its application in the assessment of hepatic warm ischemia-reperfusion injury were reviewed and summarized.ResultsThe main functional MRI techniques for the assessment of hepatic warm ischemia-reperfusion injury included the diffusion weighted imaging (DWI), intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), blood oxygen level dependent (BOLD), dynamic contrast enhancement MRI (DCE-MRI), and T2 mapping, etc.. These techniques mainly used in the animal model with hepatic warm ischemia-reperfusion injury currently.ConclusionsFrom current results of researches of animal models, functional MRI is a non-invasive tool to accurately and quantitatively evaluate microscopic information changes of liver tissue in vivo. It can provide a useful information on further understanding of mechanism and prognosis of hepatic warm ischemia-reperfusion injury. With development of donation after cardiac death, functional MRI will play a more important role in evaluation of hepatic warm ischemia-reperfusion injury.
Objective To investigate the research base and current understanding of the mechanism of ischemia-reperfusion injury (IR) to intrahepatic cholangiocytes after l iver transplantation, so as to identify the key points of the mechanism and provide references for cl inical practice. Methods We searched PubMed (1970 to 2007) and CBM(1979 to 2007). Qual ity assessment and data collection were performed by two reviewers independently. Since the baseline supplied and the measure were very different, we decided to provide a descriptive summary only. Results The earliest study on liver IR was publ ished in 1970. A total of 65 papers were included. There were 13 on cl inical studies, 35 on basic research studies; and 17 review articles. Most basic studies focus on injury mechanism: ① The physiology of bile ducts and Intrahepatic Bil iary Duct Cells(IBDC); ②the IR caused injury mechanism of IBDC during or after liver transplantation; ③ the basic injury mechanisms include: cold ischemia, warm ischemia, reperfusion, injury of bile and bile salts. Most clinical studies focused on preventive measures, including surgical and non-surgical approaches. Based on the evidence from basic research, changing the composition and perfusion methods of perfusate and protecting the specific blood supply to biliary ducts and cholangiocytes during the operation were important in preventing or reducing such an injury. Conclusion ① The heterogeneity of morphology, function, status and the special blood supply in large and small IBDC are important material base. ② Our own study indicated that simple IR or H/R was able to change the expression of MHC, MIC, DR4, DR5 and other adhesion molecules. ③ Compared to hepatic cells, hIBDC can’ t resist cold ischemia and even worse in tolerating reperfusion injury. ④ Hydrophobic bile salts will could increase the harm to bile ducts during organ preservation. ⑤ Due to the low quantity and limited quantities of clinical researches, the power of evidence was low. The evaluation indexes and baseline conditions are not unified. So the conclusions are for reference only.
【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 injury on isolated testes induced by ischemia/reperfusion(I/R), and the protective effect of Yisheng injection on the injury. METHODS: Twenty-six isolated cadaver testes contributed by 13 persons were preserved with 4 degrees C 250 ml hypertonic citrate alloxuric (HCA) solution and then reperfused with 37 degrees C 500 ml HCA. Solution of experimental group contained 500 micrograms/ml Yisheng injection. In simple cold preservation test, involving in 8 experimental and 8 control testes, a series of time points (6, 12, 18, 24, 36, 48, 60, 72 hours) were set to harvest. 10 testes (1 testis respectively on 6, 12, 18, 24 and 36 hours in experimental and control groups) were reperfused with 37 degrees C HCA for 6 and 12 hours. Histological and histochemical changes were observed. RESULTS: In the experimental testes, 4 degrees C cold preservation in 24 hours could not induce obvious pathologic changes. After 24 hours, changes such as swelling, vacuolar degeneration or detachment of endothelial cells (ECs), separation between basement membrane and seminiferous epithelium, mal-alignment of spermatogenous cell and edema of mesenchyme could be observed. In the testes preserved for 12 hours, the activity of lactic dehydrogenase(LDH) and succinic dehydrogenase (SDH) increased, then fallen after 24 hours. The activity of Nitric oxide synthetase(NOS) decreased after 18 hours. All changes were more obvious after following 37 degrees C reperfusion. In the control testes, swelling and vacuolar degeneration of ECs occurred on 12 hours cold preservation, and injury was worse along with the prolongation of cold preservation time. Pathologic changes of ECs, seminiferous epithelium and mesenchyme were serious after 37 degrees C reperfusion. CONCLUSION: 4 degrees C cold preservation in 24 hours can only cause mild ECs’ injury, and obvious abnormal testes’ histological profile can be observed beyond 24 hours. 37 degrees C reperfusion will make injury worse. Yisheng injection can keep isolated testes histologic structure well in 24 hours cold preservation, and it has protective effect on I/R injury.
