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)
Objective Biliary epithelial cell (BEC) proliferated actively induced by ischemia-type biliary lesion (ITBL), which played an important role in the development of biliary complication after orthortopic liver transplantation (OLT). The aims of this study is to provide novel method to protect the liver endured cold preservation and reperfusion injury (CPRI) and reduce posttransplant biliary complication, and explore its possible mechanism.Methods Based on constructed OLT models for studying ITBL, the hepatic oval cell (HOC) or the IL-13 genemodified HOC to the portal vein of the recipient 〔OLT+HOC group and OLT+IL-13· HOC group〕 were-transfused, then the pathology change, the liver function and the expressions of the α-smooth muscle actin (αSMA) and Heme oxygenase-1 (HO-1) mRNA of the transplanted liver of CPRI were observed, the proliferation of BEC and survival rate of the recipients were also observed. Results The BEC injury was showed in grafts with prolonged ischemia time, characterized by induction of BEC proliferation, liver function injury and cholestasis sign reflecting the increase of serum ALT, AST and TBIL. The OLT+IL-13·HOC group had better results than OLT and OLT+HOC group, which indicated the OLT+IL-13·HOC group had low level of expression α-SMA (after operation 7 d, Plt;0.05) and proliferation of BEC (after operation 3 d, Plt;0.05). The expressions of HO-1 mRNA were higher in OLT+IL-13·HOC group than in other groups. The survival rate of OLT group was lower than that of the OLT+IL-13·HOC group and sham operation group (Plt;0.05).Conclusion High expression level of IL-13 in recipient rats could promote the expression of HO-1 mRNA in transplant liver, and profit to protection donor liver, and recover of the liver function after liver transplantation. It perhaps is the mechanism of protective effect of IL-13 on graft that stimulate the expression of HO-1 mRNA significantly.
Objective To investigate whether protease inhibitor (ulinastatin, UTI) can protect liver from ischemiareperfusion injury in hepatocellular carcinoma (HCC) patients undergoing hepatectomy after hepatic inflow occlusion. Methods A prospective randomized control study was designed. Thirtyone HCC patients undergoing hepatectomy after hepatic inflow blood occlusion were randomly divided into the following two groups. UTI group (n=16)， 1×105 units of ulinastatin was given intravenously in operation, then the dosage was continuously used twice a day up to 5 days postoperatively. Control group (n=15), the patients received other liver protective drugs. Liver function, plasma C-reactive protein (CRP) and cortisol level were compared between these two groups. Results The postoperative liver function of the UTI group was significantly improved compared with the control group. For example, on the third postoperative day the aspartate transaminase (AST), alanine transaminase (ALT) and total bilirubin level in the UTI group were significantly lower than those in the control group, respectively (P＜0.05). On the first postoperative day, the plasma CRP concentration in the UTI group was significantly lower than that in the control group(P＜0.01). The plasma cortisol level in the control group markedly increased compared with the level before operation(P=0.046). However, there was no significant difference in the UTI group between before and after operation. Conclusion Ulinastatin can effectively protect liver from ischemia/reperfusion injury in HCC patients undergoing hepatectomy performed after hepatic inflow occlusion. Also, it can relieve the surgical stress for patients.
Objective To provide experimental evidence for the clinical application of ischemia therapy to treating pancreatic cancer. Methods After the model of pancreatic transplanted cancer was established in nude mice with orthotransplantation of human pancreatic cancer cell line into the pancreas, the ischemia of the right lobe of the pancreas was induced with ligation of the gastroduodenal, inferior pancreaticoduodenal and dorsal pancreatic arteries. Effects of regional ischemia on the growth of transplanted cancer and the pathomorphology of the transplanted cancer and pericancerous tissue were investigated. Results The transplanted cancer grew slower and its doubling time was longer in the ischemic group than in the control. On the 3rd, 7th and 14th day after operation, the size of transplanted cancer, the proliferative index and protein content of the cancer cells were significantly lower in the ischemic group than in the control (Ｐ＜0.01). Optical microscopy revealed large areas of coagulation necrosis, necrobiotic cells and the infiltration of inflammatory cells. The atrophy of acini, fibrosis and the infiltration of lymphocyte cells were found in pericancerous tissue. Conclusion Regional ischemia can destroy and inhibit the pancreatic transplanted cancer in nude mice effectively. The ischemia changes of pericancerous tissue may be unfavourable for the growth of the pancreatic transplanted cancer.
【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 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.
Objective To investigate the effects of adenosine 2A receptor (A2AR) activation on oxidative stress in small-forsize liver transplantation. Methods A rat orthotopic liver transplantation model was performed using 40% graft, 18 recipients were given intravenously saline (control group), CGS21680 (A2AR agonist, CGS21680 group) or ZM241385 (A2AR antagonist, CGS21680+ZM241385 group) randomly. Aspartate aminotransferase (AST), enzymatic antioxidants 〔superoxide dismutase (SOD); catalase (CAT); glutathione peroxidase (GSH-Px)〕, non-enzymatic antioxidants 〔ascorbic acid (AA); glutathione (GSH); α-tocopherol (TOC)〕 and lipid oxidant metabolites malondialdehyde (MDA) were measured and analyzed at 6 h after reperfusion. Results Compared with the control group and CGS21680+ZM241385 group, A2AR activation increased the activities of SOD and GSHPx (Plt;0.05), reduced the productions of AST and MDA (Plt;0.05), increased the levels of AA, GSH and TOC (Plt;0.05) in CGS21680 group. But there was no significant change in CAT activity (Pgt;0.05) among 3 groups. Conclusions A2AR activation improves the antioxidant enzyme activities, promotes the production of antioxidants, and slowes down the increase in MDA level, depresses of the increase in AST activity. A2AR activation suppresses oxidative damage and increases the antioxidant capacity which in turn minimizes their harmful effects of ischemia-reperfusion in small-for-size liver transplantation.
Objective To investigate the protective effects of liposome prostaglandin E1（Lipo-PGE1） on myocardial ischemia-reperfusion injury （MIRI） during cardiopulmonary bypass （CPB）. Methods Thirty-two patients with clearly diagnosed heart valve disease and congenital heart disease such as atria septal defect （ASD） and ventricular septal defect （VSD） were selected in our hospital. The patients were randomly divided into two groups （16 patients in each group）, Lipo-PGE1 group： Lipo-PGE1（2ng/kg·min） was continuously pumped before starting of CPB until 2 h after ascending aortic off-clamping; control group： using the same volume of normal saline, arterial blood samples were taken before CPB, at 1, 2, 6 and 24 h after the ascending aortic off-clamping. The value of cardiac troponin I （cTnI）, creatine kinase MBmass （CK-MB）, interleukin-6 （IL-6）, tumour necrosis factor-α （TNF-α）, intercellular adhesion molecule-l（sICAM-1） were measured. Results cTnI, CK-MB, IL-6, TNF-α and sICAM-1 showed no significant difference in the two groups before CPB （P〉0. 05）. At 1,2, 6 and 24h after ascending aortic off-clamping, those values rose significantly than before CPB（P〈0. 01）, but Lipo-PGE1 group＇s values were lower than those in the control group （P〈0. 05）. Conclusions Lipo-PGE1 （2ng/kg·min） continuously pumped from before CPB to 2h after ascending aortic off-clamping can inhibit effectively the production of IL-6, TNF-α, and reduce the expression of sICAM-1, attenuate the process of inflammation, lighten the injuries of myocardial cells, and effectively protect the MIRI during CPB open heart surgeries.
【Abstract】 Objective The present study employed both static and dynamic imaging modal ities to study bothintra- and extravascular events attributing to steroid-associated osteonecrosis (ON) using an experimental protocol with a single low-dose l i ppolysaccharide (LPS) injection and subsequently three injections of high-dose methylprednisolone (MPS). Methods Fourteen 28-week-old male New Zealand white rabbits received one intravenous injection of LPS (10 μg/ kg). After 24 hours, three injections of 20 mg/kg of MPS were given intramuscularly at a time interval of 24 hours. Additional 6 rabbits were used as controls. Dynamic MRI was performed on bilateral femora for local intraosseous perfusion before and after LPS injection. Blood samples were collected for haematological examinations before and after LPS injection. Bilateral femora were dissected and decalcified for microCT-based microangiography. ON lesion, intravascular thrombus and extravascular marrow fat cell size were examined histopathologically. Results Intravascular thrombus was observed in all ON rabbits. Extravascular marrow fat cell size was significantly increased in ON rabbits than that of the controls (P lt; 0.05). Compared to basel ine, a significant decrease in ratio of tissue-type-plasminogen-activator/plasminogen-activator inhibitor 1,activated-partial- thromboplatin-time, and a significant increase in ratio of low-density-l ipoprotein/high-density-l ipoprotein were only found in ON rabbits (P lt; 0.05). Dynamic MRI showed a significant decrease in the perfusion index ‘maximum enhancement’ in the ON rabbits (P lt; 0.05) and microCT-based microangiography showed blocked stem vessels in ON samples.Overall, 93% of the rabbits (13/14) developed ON and no rabbits died throughout the experiment period. Conclusion Bothintra- and extravascular events were found attributing to the steroid- associated ON based on our experimental protocol with a single low-dose LPS injection and subsequent three injections of high-dose MPS. Both high ON incidence and no mortal ity in rabbits treated with this inductive protocol suggested its effectiveness for future studies on evaluation of therapeutic efficacy of interventions developed for prevention of steroid-associated ON.
Objective To observe the protective effects of diazoxide-preconditioning on myocardial ischemiareperfusion injury of rats and discuss its possible mechanisms. Methods Fourteen healthy SD rats were randomly divided into two groups（7 each group）,In diazoxide-preconditioning group diazoxide was injected with the dosage of 12.5mg/kg through the vein,and in control group the media with the same amount was only given before ischemia. The left anterior descending branch was ligated for 2 hours. The heart was quickly excised after 2 hours reperfusion to be used for measurement of the quantity of malondialdehyde（MDA）, the activity of superoxide dismutase （SOD）, the size of myocardial infarct area, and the cell apoptosis and ultrastructure in ischemic area. Results Compared with the control group, the quantity of MDA,the percentage of the weight of myocardial infarct area/ischemic area, and the rate of cell apoptosis in the diazoxide-preconditioning group were greatly reduced （P〈0.05, 0. 01）. The damage of cell uhrastructure was obviously alleviated,Conclusion Diazoxide-preconditioning provides evident cardioprotective effect on the myocardial ischemia-reperfusion injury of rats.
