Objective To investigate the protective effect of ischemic preconditioning (IP) on ischemicreperfusion injury of rat liver graft. MethodsMale Sprague Dawley rats were used as donors and recipients of orthotopic liver transplantation,the period of cold preservation and anhepatic phase were 100 min and 25 min respectively.Sixtyfour rats were randomly divided into 2 groups (n=32),control group: donor livers were flushed through the portal veins with physiological saline solution containing heparin only before harvested; IP group: before donor livers were harvested,the portal veins and hepatic arteries of them were interrupted for 10 min,and reflow was initiated for another 10 min,then did as control group.One half of each group were used to investigate 1 week survival rate of recipients,and another half of each group were used to take sample of blood and hepatic tissue after 2 hours of reperfusion of liver graft. ResultsOne week survival rate,amount of bile,serum NO and activity of antioxidase were higher in IP group than those in control group(P＜0.05),meanwhile,serum ALT,AST,LDH,TNF and superoxide in hepatic tissue were lower in IP group than those in control group (P＜0.05),and histological findings in IP group showed less injury than those in control group. Conclusion IP could increase production of serum NO,reduce the level of serum TNF and protect rat liver graft from ischemicreperfusion injury.
Objective To establish and modify a rat model of arterialized small-for-size orthotopic liver transplantation and investigate the histopathologic changes of the grafts after transplantation. Methods Modified two-cuff technique was applied to establish a rat model of 40% small-for-size orthotopic liver transplantation with a modified microvascular “sleeve” anastomosis between the celiac trunk of donors and the stump of right kidney artery of recipients. Seven days survival rate was observed, main indices of liver function, histopathologic changes of the grafts were detected on the 1st, 2nd, 4th and 7th day after transplantation, respectively. Results The successful rate of operation was 93.3%. Seven days survival rate was 60.0%. The mean time of nonhepatic time was (12.0±2.5) min. Alanine aminotransferase (ALT) and total bilirubin (TB) began to elevate on the first day and peaked on the second day after operation. Histological findings indicated that hepatic sinusoidal and central vein dilation, monocytes infiltration in partial area were found on the 1st day after operation, more diploid and polyploid hepatocytes could be observed on the 4th day after operation. Conclusion The model is easily available and highly reproducible, and the stability of the model is improved by modifying the technique. The histological changes of the grafts are mainly caused by ischemia-reperfusion injury.
Objective To investigate the significance of hepatic arterial reconstruction on the model of 40% small-for-size orthotopic liver transplantation in rats. Methods Modified two-cuff technique was applied to establish a rat model of 40% orthotopic liver transplantation. A total of 240 Sprague Dawley (SD) rats were randomly divided into 2 groups: reconstructive artery group and non-reconstructive artery group. One week survival rate was observed. Main indexes of liver function, histology and the expression of proliferative cell nuclear antigen (PCNA) of liver graft （by immunohistochemical method） were detected on day 1, 2, 4 and 7 after transplantation, respectively. Results One week survival rates of reconstructive artery group and non-reconstructive artery group were 65.0% (13/20) and 50.0% (10/20) respectively (Pgt;0.05). Alanine aminotransferase (ALT) and total bilirubin (TB) began to elevate from day 1 and peaked on day 2 after surgery in two groups. ALT in non-reconstructive artery group on day 2 and 4 were significantly higher than that in reconstructive artery group (P＜0.05). TB in non-reconstructive artery group on day 2 and 7 were significantly higher than that in reconstructive artery group (P＜0.05). Histological findings indicated that more diploid and polyploid hepatocytes and more gently dilation of central veins and hepatic sinusoids could be seen postoperatively in reconstructive artery group. The expression of PCNA of liver graft peaked on day 2 after surgery. The expression of PCNA of reconstructive artery group was higher on day 1 (P＜0.01) and lower on day 7 than that of non-reconstructive artery group after operation (P＜0.05). Conclusions Arterial reconstruction can improve liver function of liver grafts after small-for-size orthotopic liver transplantation, alleviate the histological changes and promote the regeneration of liver grafts quickly.