The Early Protective Effect On The Liver Graft In Rat Mediated By Ischemic Preconditioning Of The Small Intest

【objective】This thesis is based on the stable rat orthotropic liver transplantation (OLT) model, to investigate the early protective effect on the rat liver graft mediated by the ischemic preconditioning of the small intest.【method】1 SD rats were randomly assigned into the following experiment groups: sham operation group (S group, n=6), orthotropic liver transplantation group (OLT group, n=6), and ischemic preconditioning on the recipient rat's small intest plus orthotropic liver transplantation (IOLT group, n=6).2 Orthotropic liver transplantation model has been established.3 When the grafts were revascularized successfully and reperfused for 1h, liver samples and small intest ones were obtained from different experiment groups. The MDA and MPO in jejunum of recipients were analyzed after liver transplantation in rats. The function of liver graft was demonstrated by the level of serum ALB, TBIL, ALT, AST, and ALP. The SOD and NO were determined in serum of recipients after liver transplantation as well. The morphological change of caudate lobe of liver and intestinal epithelial basement membrane were oberserved by optics microscopy and transmission electron microscopy.【results】1 After the liver transplantation operation, the recipient is able to maintain steady respiration and heartbeat, revive and turn over.2 Available examples were 20 in both OLT group and IOLT group,of which 6 were randomly selected to obtain the samples with 14 left to observe the survival. The difference of the operation and the conservation could be neglected. The one-day-survival in OLT and IOLT group were 78.57%(11/14)and 85.71%(12/14) respectively, no significance exists, (P>0.05). The one-week-survival in OLT and IOLT group were 35.71%(5/14) and 57.14%(8/14)respectively.The survival in IOLT group was significantly longer than that in OLT group (P<0.05).3 The MDA and MPO in jejunum of recipients after liver transplantation in OLT group,IOLT group and compared with S group: MPO in OLT group is (1.808±0.073ΔA·g-1),which is significantly higher than that is in S group(0.446±0.066ΔA·g-1)and IOLT group(1.061±0.073ΔA·g-1)(P<0.01);MDA in OLT group is (0.917±0.030mmol·gprot-1)which is higher than that is in S group(0.368±0.051mmol·gprot-1)and IOLT group(0.645±0.065mmol·gprot-1) as well, (P<0.01); The difference between S group and IOLT group is significant as well, (P<0.01).4 The SOD and NO in serum of recipients after liver transplantation in OLT group,IOLT group and compared with S group: SOD in OLT group is (133.08±8.77nμ·gprot-1) and NO is (8.32±0.65ng·mL-1) which were significantly lower than those in S group and IOLT group (P<0.01).5 The TP,ALB,TBIL,ALT,AST and ALP in serum of recipients after liver transplantation in OLT group,IOLT group and compared with S group: TP in OLT group is (66.87±2.77g·L-1) and ALB is(26.07±0.60 g·L-1)which were significantly lower than those in S group and IOLT group (P<0.05);TBIL (12.40±2.90umol·L-1) ,ALT (1299.83±22.42u·L-1), AST(1862.83±211.19u·L-1) and ALP(108.50±2.35u·L-1)in OLT group were higher than those in S group and IOLT group as well, (P<0.05); TP in IOLT group is (68.87±3.70g·L-1)and ALB is(26.57±0.69g·L-1)which were significantly lower than those in S group (P<0.05);TBIL (7.80±0.80umol·L-1), ALT (644.00±214.37u·L-1), AST(772.00±85.08u·L-1)and ALP(74.33±9.16u·L-1)in IOLT group were higher than those in S group as well, (P<0.05).6 The mucosal wet weight, villus height and area in jejunum of recipients after liver transplantation in OLT group,IOLT group and compared with S group: The mucosal wet weight in OLT group is (20.67±2.16mg·cm-1), villus height is(170.83±8.89μm)and villus area is (66.17±7.19μm) which were significantly lower than those in S group and IOLT group (P<0.01);The difference between S group and IOLT group is significant as well ( P<0.01).7 Optics and transmission electron microscopy revealed that the micro-construction and ultra micro-construction of the liver graft in S group stayed normal, but in OLT group the liver graft presented hepatic cell edema, degeneration even necrosis, sinus stegnosis. The lesion of the hepatic cell and mesenchyme were milder in IOLT group than those in OLT group. The epithelial basement membrane in S group stayed normal, but in OLT group it became disrupted, collapsed, and ever disappeared. The lesion of the epithelial basement membrane in IOLT group was milder than that in OLT group.【conclusion】Ischemic preconditioning of the recipient rat small intest has an early protective effect on the liver graft. This study implies the ischemic preconditioning has an early protective effect on epithelial cells and extra cellular matrix of small intest. The early protective effect on the rat liver graft mediated by the ischemic preconditioning of the small intest might concerns with the ischemic preconditioning of small intest strengthening the intestinal tract mucosal barrier function, which might mitigate the ischemic-reperfusion injury and decrease the probability of intestinal bacterium translocation and the endotoxin absorbed into system and lymph circulation which might impair the graft liver. To emphasize the protective effect of the intestinal mucosal barrier in the liver transplantation field is meaningful and of great significance, which might mitigate the injury of graft liver during the transplantation process, improve the graft function and prolong the graft survival.