Effects of recombinant human TNFR: Fc fusion protein on rat acute liver injury induced by lipopolysaccharide / 中华急诊医学杂志

ABSTRACT

Objective To investigate the protective effects and the undedying mechanism of recombinant human tumor necrosis factor receptor Fc fusion protein (Yisaipu, rhu TNFR Fc) on the lipopolysaccharide (LPS) induced acute liver injury of rats. Method Totally48 SD rats were randondy divided into four groups , in-cluding control gronp (n = 12), Yisaipu group(n = 12), LPS gronp(n = 12) and Yisaipu + IPS group(n = 12). The models of acute liver injury were produced by injection of LPS intravenously. Being fasted for 12 h, the rats were anaesthetized (60 mg/kg pentobarbital sodium, i.p.) and cannulated into carotid arteries. The cannula was connected with the multi-channel creature signal analysis system. The rata in control group and LPS group were injected with normal saline or LPS in dose of 5 mg/kg through rats' sublingual vein respectively. While the rats in Yisaipu group and Yisaipu + LPS group was pretreated with Yisaipu in dose of 0.4 mg/kg subcutaneously 24 h be-fore normal saline or LPS infusion. Six rats of each goup were randomly selected and mean arterial pressure (MAP) were monitored for 6 h via multi-channel creature signal analysis system, and rats' survival rate was calcu-lated. The rats whose MAP less than 10 mmHg were considered to die and the alive rats during period of observa-tion sacrificed by exsanguination. The liver tissue at the same site was removed, fixing in 10% formalin or stored at -80 ℃. To detect serum TNF-α, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level, 0.2 mL blood samples were collected from the carotid artery 2 and 3 h after the injection of saline or LPS. The serum was collected from centrifuged blood samples and stored at -80 ℃. Enzyme-linked immunosorbent assay (ELISA) and flow cytometry were used to assess serum TNF-α level and bioactivity respectively. We also measured the serum ALT and AST levels, the myeloperoxiase (MPO) and superexide dismutase (SOD) activity, and malon-dialdehyde (MDA) content in liver tissue The pathology of hepatic tissue was evaluated by HE staining. Statistical-ly,the data of TNF-α level and bioactivity, ALT and AST release, and MDA content were analyzed by ANOVA, and rat survival rate were analyzed by Chi-square Tests. Results The rats in control group and Yisaipu group were all survived. Rat survival rate was significantly higher in Yisaipu + LPS group (67%) than in LPS group (17%) (P < 0.05). Serum TNF-α bioactivity was significantly lower in Yisaipu + LPS group than in LPS group [(7.3±2.8)% vs.(51.3±6.4)%, P <0.05]. Compared with IPS group, Yisaipu pretreatment decreased MDA content [(1.40±0.10)vs. (2.81±0.11) nmol/mgprot, P <0.05]and MPO acticity [(0.38±0.04) vs. (0.54±0.02) U/g, P <0.05]in hepatic tissue, while SOD activity [(188.4±20.2) vs. (142.5 ± 18.3) U/mgprot, P <0.05]was increased. The serum AST level, ALT level and the pathology in the liver were also ameliorated correspondingly. Conclusions These data suggest that Yisaipu could protect rats from LPsinduced a-cute liver injury by inhibiting TNF-α bioactivity and by enhancing anti-oxidation.