The Effect Of Thrombopoietin In Acute Liver Failure Model Induced By D-galactosamine

Objective We investigated whether TPO could attenuate liver injury after D-galactosamine(D-Ga1N)-induced acute liver failure(ALF) in rats.Methods Male Sprague Dawley (SD) rats were randomized to divide into three groups: control, model, and TPO groups. The normal rats served as control group. The rats with ALF model induced by an intraper-itoneal injection of D-Ga1N (1400mg/kg) served as model group. The rats received TPO with an single dose of0.2μg/kg intravenously, immediately after induction of ALF model, serving as TPO group.5rats from control group were sacrificed at72h after D-Ga1N injection. At12,24,48and72h after the D-Ga1N injection,5rats from model group and TPO group were sacrificed. Liver injury was assessed by histological analysis as well as serum alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil). Serum tumor necrosis factor alpha (TNF-α),and interleukin6(IL-6) were detected by enzyme-linked immunosorbent assay (ELISA). Proliferating cell nuclear antigen (PCNA) and TNF-a in liver tissue were evaluated by immunohistochemistry. In addition,10rats from model and TPO group were used to observe for the survival rate in72h after the D-Ga1N injection.Results1. The serum ALT, AST and TBil levels in model and TPO group increased at12h after the D-Ga1N injection and reached a peak at48h, but there was no significant difference between the two groups at same time points(P>0.05).2. ELISA showed serum IL-6concentration obviously increased after D-Ga1N injection in model group. It was32.37±4.67pg/ml at12h, and reached a peak at72h (264.36±74.25pg/ml). IL-6concentration slightly increased after D-Ga1N injection in TPO group. It was31.53±5.22pg/ml at12h and42.90±6.07pg/ml at72h.Serum IL-6concentration were higher in model group than TPO group at48and72h (P＜0.05).3. ELISA showed serum TNF-a concentration obviously increased after D-Ga1N injection in TPO group. It was32.22±6.35pg/ml at12h and reached a peak at72h (200.65±61.93pg/ml). TNF-a concentration slightly decreased after D-Ga1N injection in model group. It was30.80±4.33pg/ml at12h and23.00±7.20pg/ml at72h. Serum TNF-a concentration were higher in TPO group than model group at48and 72h (P＜0.05). Immunohistochemistry suggested a similar trend of TNF-α in model and TPO group like ELISA, and the optical density (OD) of TNF-α were higher in TPO group than model group at24,48and72h (P＜0.05).4. Immunohistochemistry showed the expression of PCNA increased after D-GalN injection in model group. It was21.06±2.67%at12h, and reached a peak at48h (63.79±9.75%), and then obviously decreased at72h (16.74±3.92%). The expression of PCNA was20.85±3.84%at12h, reached a peak at48h (70.21±12.88%), and kept at a high level of66.49±12.88%at72h in TPO group. The percentage of PCNA positive cell was obviously higher in TPO group than model group at72h (P<0.05).5. The liver histopathology showed the liver tissue in model and TPO group changed obviously at48h after the D-GalN injection, including structural disorder of hepatic lobules, congestion in hepatic sinusoid and central vein, inflammatory cellular infiltration and hepatocyte necrosis, and improved at72h. The liver injury was more severer in TPO group than model group at48and72h.6.72h survival after D-GalN injection was60%(6/10) in model group and20%(2/10) in TPO-treated group (P＜0.05).Conclusions TPO can increase TNF-α, and aggravate liver injury in rats with ALF model induced by D-GalN.