【Abstract】ObjectiveOn the basis of traditional transplantation model, a successful model of pancreaticoduodenal transplantation (PDT) were established in rats, which is the foundation of basic and clinical transplantation research. Methods We improved the technique of microoperation on donor and harvested high-quality graft. The dual cuff technique was applied to end-to-end anastomose proximal part of abdominal aorta and portal vein with left renal aorta and vein of recipient, and distal part of abdominal aorta was connected with Y-tube. External secretion was performed by duodenum stoma. The PDT model was finished without blocking systemic circulation and portal vein system. Random blood glucose levels and drainage were monitored postoperatively to evaluate the function of endocrine and ectocrine. Results Thirty operations were done. The total procedure of transplantation lasted 2 hours. Moreover the operation on recipient and the reconstruction of vessels took only (26±5) and (25±5) minutes, respectively. The success rate was elevated to 100%. The ectocrine function was restored within 2 hours after operation. Except for 3 cases of non-function graft because of thrombosis in cannula, the glucose level of the remaining recipients was reduced to normal level 6 h or 24 h after transplantation. The survival rate of graft function was 90% (27/30). Conclusion This model is finished without special equipment and can recover the endocrine function in advance. It is a simple and stable model, which might be used in research of the theoretical problems involved in clinical pancreas transplantation.
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.
Objective To investigate the pathological characteristics of hepatic energy metabolism changes following hepatic inflow occlusion and the tolerant limit to ischemia in cholestatic rats.Methods On the day 7 after rats biliary obstruction, the survival rate, hepatic mitochondrial respiratory function, content of ATP, and the ketone body ratio in arterial blood were investigated following the different duration of hepatic ischemia and reperfusion with portal blood bypass.Results The survival rate on postoperative day 10 was 100%, 100% and 40% subjected to 30, 60 and 90min of hepatic vascular occlusion. The hepatic energy metabolic function was decreased markedly following ischemia, and was increased markedly on 24 hours following reperfusion subjected to 30, 60min of hepatic vascular occlusion, but it had less increase with 90min of hepatic vascular occlusion.Conclusion The hepatic energy metabolic function injury is reversible in cholestatic rats, and the rats can tolerate hepatic inflow occlusion within 60min, but the hepatic energy metabolic function injury is irreversible after 90min of hepatic occlusion.
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】Objective The injury induced by hepatic artery ischemia (HAI) in the liver transplantation procedure and the protective effects of using hepatic artery bridge-conduit (HABC) technique were studied. Methods Thirtytwo dogs were randomly divided into 4 groups: control, HAI 30 min, HAI 2 h and HABC groups. We observed the pathological changes of hepatocytes and biliary tract tissues and the microstructure of chondriosome, which were based on the model of auto-orthotopic liver transplantation in dogs. Biochemical and spectrophotometric methodswere used to evaluate the content of MDA and SOD, SDH activities in the graft liver tissue respectively. Results The pathologic and electrical microscopic changes of hepatocytes and epithelial cells of bile ducts were found in HAI 30 min and HAI 2 h groups,while the content of MDA increased to （1.652±0.222） nmol/mg prot and (2.379±0.526) nmol/mg prot, and SOD activity decreased to (11.15±3.9) U/mg prot and (9.47±3.4) U/mg prot. At the same time, SDH activity was also down-regulated to 0.362±0.019 and 0.281±0.029. Compared with control group, the differences were significant (Plt;0.05, Plt;0.01). But these changes of functional index caused by HAI injury were not significant in HABC group. Conclusion The HABC technique can not only avoid HAI injury during operation but also alleviate the occurrence of complication after transplantation, especially the biliary tract complication.
Objective To summarize recent research advancement on gene therapy for hepatic ischemia-reperfusion injury (IRI). Methods Relevant references about basic and clinical researches of hepatic IRI were collected and reviewed. Results Recent experimental researches indicated that the expression of several genes and cytokines could protect hepatic cells by suppressing cell apoptosis, decreasing the production of oxyradical, remaining and improving portal venous flow, promoting bilifaction, self immunoloregulation and decreasing inflammatory reaction, so that it could decrease IRI. Conclusion IRI could be decreased by regulating the expressing of target genes or transducing relative genes in vivo, but the path of gene transfer and the selection and optimization of gene carrier still need more basic and clinical researches to prove.
Objective To observe the influences of depolarized arrest and hyperpolarized arrest on alternation of fluidity of myocardial cell membrane during cardiopulmonary bypass (CPB) and evaluate the protective effects on myocardium of hyperpolarized arrest. Methods Seventy-two felines were randomized into three groups, each group 24. Control group: 180 minutes of CPB was conducted without aortic and vena caval cross-clamping. Depolarized arrest group: hearts underwent 60 minutes of global ischemia after aortic cross-clamping (ACC) followed by 90 minutes of reperfusion. The cardioplegic solution consisted of St. Thomas solution (K+16mmol/L). Hyperpolarized arrest group: the protocol was the same as that in depolarized arrest group except that the cardioplegic solution consisted of St.Thomas solution with pinacidil (50 mmol/L,K+5mmol/L). Microviscosity, the reciprocal of fluidity of myocardial membrane was measured in all groups by using fluorescence polarization technique. (Results )Microvis cosity of myocardial cell in depolarized arrest group during ACC period was significantly higher than that before ACC and kept on rising during reperfusion period. Microviscosity of myocardial cell in hyperpolarized arrest group during ACC was trending up and reperfusion periods as well, but markedly lower compared to that in depolarized arrest group at corresponding time points(Plt;0.01). Conclusion Hyperpolarized arrest is more effective in protecting myocardial cells from ischemia-reperfusion injury than depolarized arrest during CPB by maintaining better fluidity of myocardial membrane.
【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.
Adenosine triphophate (ATP), substantially liberated from the injured cells, activates the inflammatory cells to secrete various inflammatory factors, thus triggering uncontrolled systemic inflammatory response and thrombosis with aggravating the degree of damage. Metabolic pathway of adenosine consists of adenosine (Ado) synthase CD39-CD73, nucleoside transporters (NTs) and termination system of adenosine deaminase (ADA) and adenosine kinase (ADK). As a " switch” of the inflammatory response, the metabolic pathway converts ATP (the pro-inflammatory cytokines) to Ado (the anti-inflammatory mediators), maintaining the homeostasis between pro-inflammatory and anti-inflammatory as well as affecting the outcome of the injury. This review focused on the recent progress of adenosine metabolic pathway in cell injury.
ObjectiveTo review the recent research progress about the pathogenesis and prevention of reactive oxygen species (ROS) in the hepatic ischemia-reperfusion injury (HIRI). MethodsSearched the related literatures in recent years from the databases such as CNKI, PubMed and so on, summarized the recent research progress about the generation mechanism of ROS, the damage mechanism of ROS, and the prevention method of ROS. ResultsA mass of ROS originated from polymorphonuclear leukocytes, Kupffer cells, mitochondria, and the enzymes in hepatic tissue in HIRI. It mainly destroyed sugar molecules of oligosaccharide chains on the cell membrane, unsaturated fatty acid, protein molecules, mitochondrial, and genetic material. This mechanism lead to cell injuried or even death. The main method of prevention and cure to HIRI is eliminating ROS by using enzymes, vitamins, Chinese herbal medicines etc. ConclusionsThe research about ROS in HIRI has advanced. Aiming at the damage resulted from ROS in the liver, Scholars have came up with a variety of control methods which is feasible. However, many issues need to be further investigated.