Protective effect of polymyxin B in liver transplantation in rats

Abstract

Objective To investigate the protective effect of polymyxin B (PMB) to the liver graft after liver transplantation and the underlying mechanism in rats.Methods Male SD rats were selected as the donors and recipients.Non-artery whole liver transplantation model was established in rats according to Kamada's two-cuff method.The rats were divided into two groups by the way of random number table method:control group (normal saline,0.5 ml) and PMB group (PMB,1 mg/ml,0.4 mg/kg+ normal saline 0.5 ml).The levels of portal vein plasma endtotoxin (EU/ml)were determined by endotoxin-analyzing machine of BET-24A. ALT,BUN,and TNF-α,IL-6 in serum were measured by using machine of Automatic Analyzer and ELISA,respectively.The CD14,TLR4,NFκB and AP-1 in the grafts were measured by RT-PCR and Western blotting,and pathological changes were observed. Results PMB decreased the levels of portal vein plasma endotoxin 1 h after reperfusion in PMB group as compared with control group (P＜0.05),and the levels of portal vein plasma endotoxin returned to the normal levels 6 h after reperfusion in both two groups (P＞0.05).After operation,the levels of ALT,TNFα and IL-6 in serum were significantly reduced (P＜0.05),the expression of CD14 and TLR4 mRNA in the grafts was significantly decreased (P＜0.05),the expression of Hsp60 protein and mRNA,and NF-κB and AP1 proteins in the grafts were reduced (P＜0.05),and the pathological damage to the grafts was significantly alleviated in PMB group as compared with control group.Conclusion PMB reduced the levels of portal vein plasma endotoxin after reperfusion in liver transplantation in rats.PMB improved liver function,reduced the injury of inflammatory response,decreased the levels of endotoxin signal pathway markers and alleviated the pathological damage to the grafts. Key words: Rats; Liver transplantation; Polymyxin B