Objective To investigate the relationship between surgical operation and hypophosphatemia, to observe the possible damage of hypophosphatemia and to assess the value of postoperative phosphate supplementation. Methods Sixty four male SD rats were randomly divided into 2 groups, Group Ⅰ, drinking a specially prepared solution to reduce their phosphate storage, Group Ⅱ, drinking water as a control. All received common bile duct ligation 3 weeks later. The serum biochemical data including phosphate level were obtained before and after operation. Then half of rats in each group were supplied with NaH2PO4 5-day survival rates were analyzed with statistic methods and their vital organs were observed under electron microscope. Results The phosphate level of each group was descended after operation. The group with phosphate shortage before operation (group Ⅰ) had a greatest fall of phosphate and average arterial pressure. The phosphate-supplied rats had a minor change of vital organs under electron microscope scan and higher 5-day survival rate compared to others in this group.Conclusion Abdominal surgery may induce postoperative hypophosphatemia, especially when the phosphate has been lacking before operation. Severe hypophosphatemia, superimposed on surgical trauma, enhances the damage to the body. Prompt supplement of phosphate will improve the prognosis of surgical operation.
Objective To provide a reliable experimental model for gastroesophageal reflux (GER) study. Methods Twenty Japan 5-month-old male rabbits wererandomly divided into two groups: group cardiomyotomy(n=10), group partial cardiomyectomy(n=10). The operations of cardiomyotomy and parital cardiomyectomy were performed in 2 groups respectively. All the animals underwent intraesophagealpH detection 1 week before operation and 4 weeks after operation. The mean changes of reflux ratios were compared between before operation and after operation.Results In gastroesophageal reflux ratio between before operation and after operation, there was no significant difference in group cardiomyotomy (1.98%±1.52% and 4.32%±2.39%, Pgt;0.05) and there was significant difference in group partialcardiomyectomy（1.56%±1.57% and 13.56%±3.27%, Plt;0.05）. Conclusion The reliable experimental model of GER can be made with procedure of partial cardiomyectomy. It can be used in estimating the operative procedure of antireflux and is conducive to dynamic observation and study of esophagitis.
Objective To establish a model of deep venous thrombosis (DVT) in rats for dynamic study of antithrombotics or thrombolysis on thrombosis. Methods SD rats (n=60) were randomly divided into thrombosis model group (n=36), control group (n=18) and sham operation group (n=6). An improved method was used to make the inferior caval vein ligated in SD rats of thrombosis model group. After operation, rats in thrombosis model group and control group were divided into 6 period groups. The changes of thrombus and internal surface of vessels in each period were observed in thrombosis model group and were compared with those in other two groups, respectively. Results Stable venous thrombus were observed in all inferior caval vein in thrombosis model group, and the proximal part of venous thrombus was unobstructed and consistent with the pathological change of venous thrombosis during acute stage in human body. Conclusion The DVT model in rats was successfully established, which maybe helpful for dynamic study of the effect of antithrombotics or thrombolysis on thrombosis.
【Abstract】Objective To establish animal model of orthotopic liver transplantation(OLT) in miniature pigs with high standardization, reproducibility and stability. Methods OLTs were performed without venovenous bypass in Bama miniature pigs. The survival rates and the changes of hemodynamics and metabolism were investigated. Results Twenty OLTs were performed between pairs of miniature pigs. The mean operative time and anhepatic phase were (181±25.8) min and (28.4±3.2) min respectively. During the anhepatic phase, dramatic hemodynamics and metabolism changes accompanied hyperkalemia identified. MAP and CVP decreased from (14.59±1.68) kPa and (0.66±0.11) kPa to (5.87±0.91) kPa and (0.27±0.10) kPa respectively, while temperature, pH, BE and HCO3- were significantly reduced (P＜0.05) and HR and K+ in serum were remarkable increased. After reperfusion, the disorder of hemodynamics and metabolism described above recovered gradually. 1week survival rate was 90%. Sixteen animals survived more than 2 weeks. AST, ALT and TBIL were significantly increased and reached the peak level on postoperative 1 day. From postoperative 2 day, AST, ALT and TBIL began to decrease and reached postanaesthesia level on postoperative 7 day. Conclusion The animal model of OLT without venovenous bypass in miniature pig, with its high standardization, reproducibility and stability, is an ideal one for series studies related to liver transplantation.
Objective To explore the feasibility and operation points of establishing duodenal-jejunal bypass （DJB）surgery animal model in Goto-Kakizaki （GK） rats. Methods Sixteen GK rats were randomly divided into experimental group （n=8） and control group （n=8）. In a standardized preoperative， intraoperative， and postoperative operation， the rats of experimental group and control group received DJB and sham surgery respectively. The fasting plasma glucose and body mass were observed before operation， and 1， 2， 3， and 4 weeks after operation in order to evaluate whether the models were established successfully. Survival situation of rats were observed too. Results All experimental rats survived at 4 weeks after the operation. Compared with the levels before operation， the fasting plasma glucose levels of experimental group decreased significantly （P＜0.05） at 1 week after operation， and remained stable at 2， 3， and 4 weeks after operation.The fasting plasma glucose levels of control group did not change statistically at all time points after operation （P＞0.05）. Compared with control group at the same time point， the fasting plasma glucose level of experimental group was lower （P＜0.05）， indicating that DJB models were established successfully. After 4 weeks， the value of body mass added in experimental group was significantly lower than those of control group （P＜0.05）. Conclusions DJB is a feasible， safe， and effective hypoglycemic surgery. The application of this set of experimental operating procedures can reduce the risk of intraoperative and postoperative mortality， and can develop a stable DJB model in Goto-Kakizaki rats.
To make a rabbit model of Perthes disease and to explore the change and its significance of VEGF expression in the femoral head. Methods Twenty-four 3-month-old New Zealand rabbits (weighing 1.6-1.8 kg) were randomly divided into experimental group (n=16) and control group (n=8). A rabbit model of Perthes disease was made by excision of left l igamentum teres and retinacular blood suppl ies of femoral head. The gross appearance, X-ray film and histological observations were made and the immunohistochemistry and VEGF mRNA in situ hybridization were carried out1, 2, 4, 8 weeks after operation. Results The rabbit model of Perthes disease was made successfully; only 1 was infected5 days after operation and was made quit. The gross appearance: The femoral heads had no necrosis changes in control group at every time. The femoral heads became coarse, tarnish and smaller, and even collapsed in experimental group. The HE staining observation: The femoral heads had no necrosis changes in control group at every time after operations. New vessels and granulation tissues grew into the necrosis part in the experimental group 4 weeks and 8 weeks after operations. New bone could be seen in repaired bone. Immunohistochemistry staining: In the epiphyseal cartilage of the femoral heads in control group, an intensive VEGF immunoreactivity (VEGF-IR) was found in the hypertrophic zone with a low level of VEGF-IR in the prol iferative zone. At 1 week after operation, the percentage of VEGF+ cells in the prol iferative zone of the femoral heads in experimental group was increased compared with that of the femoral heads in control group. The percentage of VEGF+ cells in the hypertrophic zone of the femoral heads in experimental group was significantly decreased compared with that of the femoral heads in control group. At 8 weeks after operation, VEGF-IR was observed throughout the epiphyseal cartilage surrounding the bony epiphysis in the femoral heads in experimental group. The percentage of VEGF-positive cells in the prol iferative zone of the femoral heads in experimental group was significantly increased compared with that of the normal heads. The hypertrophiczone of the femoral heads in experimental group had a similar percentage of the VEGF+ cells to the femoral heads in control group when endochondral ossification was restored at 8 weeks. There were statistically significant differences in the ratios of VEGF+ cells in the prol iferative zone of femoral head 1, 2, 4, 8 weeks after operations (P lt; 0.01); in the ratios of VEGF+ cells in the hypotrophic zone of femoral head 1, 2, 4 weeks after operations (P lt; 0.01) between experimental group and control group. In situ hybridization results: The results were similar to that of histology. VEGF mRNA expression in the hypertrophic zone of epiphyseal catilage after necrosis were lower. VEGF mRNA expression in the prol iferative zone of epiphyseal catilage after necrosis increased. VEGF mRNA expression in the hypertrophic zone of epiphyseal cartilage in experimental group could be seen again after endochondral ossification was repaired. Conclusion It is possible that VEGF may act as a key regulator that couples angiogenesis, cartilage remodel ing, and ossification after ischemic damage to restore endochondral ossification in the epiphyseal cartilage.
Objective To explore the feasibility of the Budd-Chiari syndrome model establishment in rat by using the inferior vena cava coarctation. Methods Fifty SD rats were randomly divided into experimental group and sham operation group， the laparotomy was performed after general anesthesia by intraperitoneal injection， and dissociated the inferior vena cava. In the experimental group， the vena cava was tightly ligated with silk thread according to partial portal vein coarctation， enclosing 23 G L-style blunt needle in the ligature to prevent complete obliteration. The diameter of the vena cava was set to about 80% of its normal size after removing the 23 G L-style blunt needle. The abdominal Doppler， liver function， blood routine examination， and liver biopsy were tested at different time （on week 1， 4， 8， and 12） after operation. Results The signs of inferior vena cava and primary hepatic venous obstruction， liver congestion and cirrhosis， ascites， hepatosplenomegaly， portal vein extension， and collateral patency occurred on week 4 in the experimental group. The levels of AST， ALT， AKP， TBIL， DBIL， and TBA in the experimental group were significantly higher than those in the sham operation group （P＜0.05）， and the WBC， PLT， RBC， HGB， and ALB in the experimental group was significantly lower than those in the sham operation group （P＜0.05）. Conclusion The inferior vena cava coarctation can be successfully used to establish a rat model of Budd-Chiari syndrome.
ObjectiveTo establish paraquat (PQ)-induced acute respiratory distress syndrome (ARDS) mice model via gavage, in order to simulate oral adminitration in clinical situations.MethodsSeventy-eight 6-8-week-old, specific pathogen free female C57 mice were chosen in this study. The mice were randomly divided into the control group (n=6) and the PQ model group(n=36); the mice in the latter group were randomly divided into 6 poisoning model subgroups further, with 6 mice in each, to find out the suitable concentration of PQ to establish stable ARDS model. The mice in the control group were given phosphatebuffer saline (PBS) by gavage, 200 μL per mouse; while the mice in the 6 poisoning model subgroups were given PQ with varies doses of 3, 10, 30, 100, 150, 300 mg/kg respectively by gavage. The clinical manifestations were observed for 7 days, and the ratio of lung wet/dry (W/D) was measured. After the suitable concentration of PQ for stable ARDS mice model was found, the other 36 mice were randomly divided into the controlgroup and the poisoning model group, both were divided into 4 subgroups, according to different observation point in time (1 day and 2, 3, 4 days after PQ gavage). The mice in the 4 control subgroups (n=3) were given PBS by gavage, 200 μL per mouse; while the mice in the 4 poisoning model subgroups (n=6) were given PQ with the suitable concentration for ARDS mice model by gavage. Pathological manifestations by Haematoxylin-Eosin staining and lung injury score were observed and analyzed.ResultsThe mice began to die at the PQ dosage of 150 mg/kg; while the death rate was stable at 300 mg/kg. On the 2nd and 4th day after PQ gavage, lung W/D was 5.335, 6.113, and 5.525, and 6.403, respectively in the mice in 150 and 300 mg/kg subgroup, which differed much from those in the control group (P<0.001). Congestion, edema, hemorrhage, alveolar structure damage, inflammation cells infiltration of lung tissue were observed, and lung injury score increased.ConclusionPQ-induced ARDS mice model by gavage is established successfully.
Objective To investigate the surgical technique of establ ishing a rel iable rat model of orthotopic l ivertransplantation. Methods A total of 200 adult male SD rats weighing 200-250 g and 60 adult male Wistar rats weighing230-280 g were adopted. The weight of donor was 30 g less than that of receptor. Syngeneic group of SD-SD rats (SD-SD group, n=70) and allogeneic group of SD-Wistar rats (SD-Wistar group, n=60) l iver transplantation were performed, respectively. Orthotopic l iver transplantations in rats were performed using modified Kamada’s two-cuff technique. Under the sufficient exposure of the porta hepatis, the l iver was perfused through the cold of perfusion of portal vein without touching the l iver. The anastomosis of the suprahepatic vena cave was sutured end- to-end with 8-0 prolene l ine. Guided by double l ine, the continuity of portal vein was establ ished by cuff method easily. The fluid was supplemented sufficiently after operation to maintain the stabil ization of hemodynamics. Results The time for donor operation and receptor operation was (38.2 ± 2.5) minutes and (45.6 ± 3.5) minutes, and anhepatic time was (15.1 ± 2.2) minutes.The successful rate was 93%. The survival rate after 1 week was 92%. There was a significant difference when compared with traditional method (P lt; 0.05). There were 64 survivals in SDSD group and 57 in SD-Wistar group after l iver transplantation, and the survival time was 2-9 months (mean 145 days) and 8-20 days (mean 10.5 days) respectively. The l iver function recovered well in SD-SD group, while in SD-Wistar group the l iver functional failure and acute rejection occurred in pathology 3-5 days after l iver transplantation, all of which ended with death without any therapy. Conclusion The modified method is proved to be ideal for its advantages of simple operation, short anhepatic phase and high operative successful rate.
ObjectiveTo compare two different ways to establish mouse model with acute lung injury (ALI) via intratracheal instillation or intraperitoneal injection of lipopolysaccharide (LPS). MethodsBALB/c mice received intraperitoneal/intratracheal administration of LPS or sham operation. Wet/dry lung weight ratio, protein concentration in bronchoalveolar lavage fluid (BALF), and lung tissue histology were examined at 0, 1, 2, 6, 12, 18, 24, 48 h after LPS administration. Tumor necrosis factor-α (TNF-α) in BALF and serum was assayed with ELISA method. ResultsLPS treatment significantly increased wet/dry lung weight ratio, BALF protein concentration and TNF-α concentration in serum and BALF. Lung tissue was damaged after LPS challenge. The mice received LPS intraperitoneal injection got a more significant lung edema than those received LPS intratracheal instillation. Inversely, LPS intratracheal instillation induced more severed microstructure destruction. ConclusionsALI animal model by LPS intratracheal instillation or intraperitoneal injection induces inflammation and tissue damage in lung. However, the degree of tissue damage or self-healing induced by two methods is different. Therefore the decision of which way to establish ALI model will depend on the study purpose.