A acute partial obstructive hepatocholangitis model by selective ligation and injection of E coli into left hepatic bile duct was successfully founded in rat. Using parameters including mortality, mitochondrial glutamic oxalacetic transaminase and ornithine carbamoytransferase activity, pathological observation and blood culture of bacteria, we evaluated the model. The authors emphasize that this models is superior to the wole-bile-duct-challenged cholangitis model, which is characterized by liver injury.
Liver transplantation in hamster-to-rat is a good model for the research in xenograft, but it is difficult to be performed. In order to simplify its procedures, 38 cases of liver transplantation in hamster-to-rat were performed with several technique improvments on the basis of orthotopic liver transplantation in rats. In the light of hamster’s anatomy, three cuffs anastomosis method was used. Because of its high stability and high survival rate, the model can be used widely as the research for liver xenograft.
ObjectiveTo investigate the expression of caspase-3 and Toll-like receptor 4 (TLR4) in the incised rat skin healing process and its relationship with the wound time and to provide an experimental evidence for the prediction of injury time. MethodsAfter the rat incised wound model was established, hematoxylin-eosin dyeing technology and immunohistochemical staining technique were used to observe the expression of caspase-3 and TLR4. Then Image Pro Plus Image analysis software and SPSS statistical analysis software were used to deal with the experimental results. ResultsCaspase-3- and TLR4-positive cells were detected in epidermis, hair follicle and sebaceous gland cells in the control skin. The expression of caspase-3 and TLR4 of the ante mortem groups were significantly different compared with the control group except the 0 h group (P<0.05). Caspase-3- and TLR4-positive cells were detected in neutrophils around the hair follicle half an hour later. Caspase-3- and TLR4-positive cell rate increased with the infiltration of inflammatory cells. Caspase-3- and TLR4-positive cell rate reached the maximum on the 3 rd day, and then it began to decrease, and they were mainly expressed in fibroblasts and mononuclear macrophages. Caspase-3- and TLR4-positive cells were mainly expressed in fibroblasts on the 10th day. There was no significant differences between the postmortem injury groups and the normal control groups (P>0.05). ConclusionCaspase-3- and TLR4-positive cell rate is time dependent and stable in 25℃ temperature environment which makes it possible to determine the time of injury.
ObjectiveTo evaluate the effect of pre-infusion of allogeneic lymphoyctes treated with 5-FU on the rat liver graft. MethodsRat liver transplant models from Wistar to SD were established. Four groups were designed as following: control group: only liver transplantation without any other intervention; lymphocytes group: 1 ml of untreated lymphocytes (5×106/ml) from Wistar rats were preinfused into SD rats on day 7 and 4 separately before transplantation; lymphocytes with low concentration of 5-FU group: low concentration 5-FU (7.5 μg) treated lymphocytes were preinfused as above; lymphocytes with high concentration of 5-FU group: high concentration 5-FU (15 μg) treated lymphocytes were preinfused as above. Fas-L and CD8 expression were detected by immunohistochemistry method on day 7 after transplantation. ResultsThe integral opticaldensity (IOD) of Fas-L positive lymphocytes in the lobules of liver and portal areas were higher in lymphocytes with low concentration of 5-FU group than in the other groups （Plt;0.05）. There was no difference between lymphocyte group and lymphocytes with high concentration of 5-FU group （Pgt;0.05）. The IOD of CD8+ expression in lobules of liver was not different among all the three lymphocytes treated groups （Pgt;0.05）. But in portal areas, CD8+ expression was lower in the lymphocytes with low concentration of 5-FU group than in the other groups （Plt;0.05）. ConclusionPreinfusion of lymphocytes treated with low concentration 5-FU can induce graft immune tolerance, the probable mecanism of which is the increasing Fas-L expression in graft.
Objective Series of compl icated molecule signal pathway are involved in the bone regeneration. To explore the possibil ity of nuclear factore kappa B (NF-κB) which is taken as the “key activation” during the fracture healing and provide the laboratory evidence for the gene therapy of nonunion or delayed union of fractures. Methods Thirtythree adult male Wistar rats (weighing 180-220 g) were selected and divided randomly into 4 groups: group A (the control group, n=3), the rigth lower segments of radius were injected with normal sal ine 0.3 mL for 7 days, once per day; group B (Bay 11-7082 injection group, n=6), the middle and distal radius were injected with normal sal ine containing 50 μmol/L NF- κB inhibitor Bay 11-7082 0.3 mL for 7 days, once per day; group C (fracture group, n=12), the right middle and distal radius were cut by a sharp scissors to form per fracture model; and group D (Bay 11-7082 treatment group, n=12), based on group C, 0.3 mL of 50 μmol/L Bay 11-7082 were injected into the fracture site for 7 days, once per day. The callus tissues were harvested at 3, 7, 14, and 28 days after fracture for Western blot analysis, alkal ine phosphatase (ALP) activity assessment, prostaglandins E2 (PGE2) production assay, and histological observation. Results The rats of all groups were survivaltill the experiment completion. At 3 and 7 days after injection, there was no significant difference in the ALP activity and PGE2 production between group B and group A (P gt; 0.05); but group C was significantly higher than group A (P lt; 0.01) and group D was significantly lower than group A (P lt; 0.01). The expressions of NF-κB p65, bone morphogenetic protein 7 (BMP-7), and inhibitor of DNA binding 2 (Id2) were observed at fracture sites of 4 groups. There was no significant difference in the expressions of NF-κB p65, BMP-7, and Id2 between group B and group A (P gt; 0.05); the expressions of NF-κB p65 and BMP-7 were significantly higher and the expression of Id2 was significantly lower in group C than group A (P lt; 0.01); and the expressions of NF-κB p65 and BMP-7 were significantly lower and the expression of Id2 was significantly higher in group D than group A (P lt; 0.01). The histological observation showed that a lot of osseous callus formed in group C at 14 and 28 days, but osseous callus just began to form in group D at 28 days. Conclusion NF-κB p65 can facil itate early fracture heal ing of rat radius by elevating the PGE2 production and regulating BMP-7 and Id2 expression.
Objective To explore the liver regeneration following partial liver transplantation. MethodsPartial liver transplantation in the rats were established, three experimental groups were: Ⅰ=control, partial liver resection; Ⅱ=orthotopic liver transplantation (OLT); Ⅲ=partial orthotopic liver transplantation (POLT). Liver function test, morphological investigations and liver regeneration were performed in different time after transplantation. The regenerative response of transplanted partial liver graft in rats were evaluated by Flow Cytometry and compared it to liver regeneration following resection.Results The serum concentrations of ALT, BILI increased in one week, but returned gradually to normal level within one month after transplantation. Large numbers of mononuclear cells infiltrating into the portal areas. Hepatocyte necrosis was observed on day 14 after transplantation. On day 30, the parenchyma cell showed a nearly normal appearance, bile duct proliferation was seen in portal areas. In addition, after liver resection and POLT some diploid hepatocytes were found. Dilation of the central veins, adjoining sinusoids and interlobar veins were seen in group Ⅲ. The partial liver graft is capable of regeneration similar to the situation following partial hepatectomy. The peak of liver regeneration was seen on day 1,2,4 following a hepatectomy and POLT and OLT, respectively.Conclusion The transplanted liver shows the same and/or enhanced regeneration compared to controls. There are several possible explanations for the slight delay in achieving the maximal regenerative response in rats undergoing the POLT and OLT. These may include damage that is induced by the operation itself, preservation, and reperfusion injuries. These suggest that this be caused by activation of the immune system and it might be related to the regulation of cytokines and hormone.
Objective To explore the effects of several immunosuppressants on the cell numbers of cultured rat macrophages and Schwann’s cells. Methods The macrophages and Schwann’s cells were cultured from the newborn Wistar rats. Different concentrations of methylprednisolone(10-3, 10－4,10－6 and 10－8 mol/L), CsA(10－5, 10－6, 10－7 and 10－8 mol/L) and FK506(10-6, 10－7, 10－8 and 10－9 mol/L) were administrated to the cells, while control group was given no drugs. Twentyfour, 48 and 72 hours after administration, the cells from different concentrations were measured with MTT methods respectively. Theresults were compared and analyzed statistically. Results Only high concentration methylprednisolone (10-4 mol/L) and a certain range of concentrations of CsA (10-6，10-7 and 10-8 mol/L) and FK506 (10-7,10-8 and 10-9 mol/L) can provide protection to culturedrat macrophages. Under most concentrations, CsA and FK506 had no effects onthe cell number of cultured rat Schwann’s cell. Only with high concentration CsA (10-5 mol/L) and methylprednisolone (10-3 mol/L) could significantly decreased the cell number of Schwann’s cell. Long time (72 hours) and low dosage (10-8 mol/L) administration of methylprednisolone could significantlyprotect Schwann’s cell. Conclusion High concentration methylprednisolone and some certain concentration CsA and FK506 can protect cultured rat macrophages. But high concentration CsA and methylprednisolone prohibit the proliferation of Schwann’s cells. Only long time and low dosage methylprednisolonecan protect cultured rat Schwann’s cells.
Objective To establish the rat orthotopic liver transplantation model by characterizing the blood supply of hepatic artery with the Cuff skill and the modified arterial sleeve anastomosis, to explore the possible mechanisms of acute rejection and the express of Fractalkine (Fkn) in the early stage after hepatic allograft operation. Methods SD rats were selected as donors and Wistar rats as receptor for the rejection model of orthotopic liver transplantation. Recipient rats were divided into 2 groups randomly after operationand the drugs were given intraperitoneally once a day in each group. In the experimental group, cyclosporine A (CsA) was delivered with 3 mg/kg. In the control group, only normal saline was given with 3 ml/kg. Condition of survivals were observed. The rejection actvity index (RAI) and the expression of Fkn of liver tissue were observed after 3rd, 5th and 7th days in 5 rats. The rest of rats in each group were fed and given drug or normal saline until they were died and the mean survival time were recorded. Results There were 18 survivals in control group, and 19 in experimental group after liver transplantation. Condition of survivals in experimental group was better than that of control group. The mean survival times of experimental group(19.50±4.51 days) was significantly longer than that of control group(7.60±1.60 days), showing statistically significant difference (P＜0.05). After 3rd, 5th and 7th days of transplantation, RAI of control group were 3.80±0.35,5.90±0.87 and 7.50±1.30,respectively;RAI of experimental group were 3.10±0.21,3.90±0.41 and 4.50±0.52.Therewasstatistically significant difference in RAI between 2 groups on the 7th day after transplantation (Plt;0.01). On the 3rd,5th and 7th days after transplantation, the Fkn of control group was 8.20±0.57,21.30±3.30 and 25.70±4.91, and that of experimental group was 8.30±0.56,10.30±0.67 and 11.70±1.23. There were statistically significant differences in Fkn between 2 groups on the 5th, 7th days after transplantation (Plt;0.01). Conclusion Fkn is a participant inacute rejection after the rat orthotopic liver transplantation and can be chosen as a useful target in the diagnosis of acute rejection. CsA has immunosuppressive property in the condition of acute rejection in the rat orthotopic liver transplantation, which may be result from the decreased the level of Fkn.
【Abstract】Objective To investigate the surgical technique of orthotopic liver transplantation using two-cuff technique and prevention of operational complications in rats. Methods The model was established with modified cuff technique.Before donor livers were harvested,the portal vein and hepatic artery were interrupted for 10 min,and reflow was initiated for another 10 min.The donor liver was perfused through abdominal aorta and portal vein respectively.The infrahepatic vena vein and portal vein were anastomosed by means of cuff method； the anastomosis of the suprahepatic vena vein was performed with suture method. The anastomosis of the common bile duct was performed with an internal stent. Results One hundred and twenty rats underwent orthotopic liver transplantation using twocuff technique and the successful rate was 90.8%. The average nonhepatic time of recipients was (21.0±3.5) min and the total surgical time was (46.0±4.5) min. The oneweek survival rate of recipients was 87.2%. Conclusion Good exposure of operative field, sophisticated microsurgical technique and delicate surgical manipulation can benefit decreasing nonhepatic and total surgical time of recipients and increasing the survival rate of recipients.
OBJECTIVE To determine the role of endogenous carbon monoxide(CO) in oxidant-mediated organ injury following limb ischemia-reperfusion (I/R) in rats. METHODS: Sixty-four SD rats were divided into 4 groups: Sham group, Sham + zinc protoporphyrin (ZnPP, an inhibitor of heme oxygenase activity), 2-hour ischemia followed by 4-hour reperfusion (I/R) group and I/R + ZnPP group. Carboxyhemoglobin (COHb) level in the artery blood, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung, heart, liver and kidney were detected. The 24-hour survival rate of rats was studied. RESULTS: Compared with the sham group, the COHb level and MDA content significantly increased, while the SOD activity and the survival rate significantly decreased in I/R group (P lt; 0.05). Compared with the I/R group, MDA content significantly increased, while the SOD activity, the 24-hour survival rate and COHb level significantly decreased in I/R + ZnPP group (P lt; 0.05, respectively). CONCLUSION: Limb I/R could lead to the oxidant-mediated multiple organ injury accompanied by the increase of CO level which play an important role in the defense against I/R-induced remote multiple organ injury in rats.