Protective effects of agmatine on severe trauma induced acute hepatic injury / 中华危重病急救医学

ABSTRACT

Objective To observe the effect of agmatine (AGM) on inflammatory factor in Kupffer cells of liver,and to investigate the protective effects of AGM on severe trauma-induced liver injury in mice and its possible mechanism.Methods Forty-two adult male BALB/c mice were randomly divided into sham group,model group,and AGM treatment group,with 14 mice in each group.The mice model of trauma-hemorrhage was reproduced by hindlimbs fracture combined with 35％ of orbital bleeding.The mice in the sham group were only anesthetized without other treatments.The mice in AGM treatment group were given intraperitoneal injection of 200 mg/kg AGM when limited recovery was performed,and the mice in model group were given the equal amount of normal saline.Seven mice in each group were sacrificed at 12 hours and 24 hours,respectively,after modeling,and blood samples and liver tissue were harvested,and liver Kupffer cells were isolated.Serum alanine aminotransferase (ALT),aspartate transaminase (AST)and lactic dehydrogenase (LDH) were determined with automatic biochemistry analyzer.Hepatic pathological changes were observed with light microscope using hematoxylin and eosin (HE) staining.The levels of tumor necrosis factor-α(TNF-o) and interleukin-6 (IL-6) in serum,hepatic homogenate and Kupffer cell supernatant were determined with enzyme linked immunosorbent assay (ELISA).The mRNA expressions of pro-inflammatory cytokines TNF-α and IL-6 in the Kupffer cell were determined by real-time fluorescent quantitation reverse transcription-polymerase chain reaction (RT-qPCR).Results ① The normal liver tissue structure was found in sham group.At 24 hours after modeling in the model group,the changes in pathobiology were found as followingneutrophil infiltration,hepatocytes swelling,hyperemia,and necrosis,as well as the abnormality of parameters reflecting liver function.AGM could significantly improve the pathological changes in liver tissue caused by severe trauma,and ameliorate the liver function.② There were no significant differences in the levels of TNF-α and IL-6 in serum and hepatic tissue at 12 hours after modeling,and the parameters at 24 hours in model group were higher than those at 12 hours,which were significantly higher than those of the sham group [serum TNF-α (ng/L)80.8±4.7 vs.34.7±4.7,IL-6 (ng/L)104.0±9.0 vs.55.4±3.3;liver TNF-α (ng/mg)405.2± 19.6 vs.57.2±10.0,IL-6 (ng/mg)58.4±7.7 vs.14.3±2.1,all P ＜ 0.01].AGM could effectively reduce the levels of TNF-o and IL-6 in serum and hepatic tissue [serum TNF-α (ng/L)58.2 ± 3.1 vs.80.8 ± 4.7,IL-6 (ng/L)74.1 ± 6.6 vs.104.0± 9.0;liver TNF-α (ng/mg)248.7 ± 22.5 vs.405.2 ± 19.6,IL-6 (ng/mg)22.5 ± 3.1 vs.58.4 ± 7.7,all P ＜ 0.01].③ The levels of TNF-o and IL-6 in Kupffer cells supernatant were significantly higher than those of the sham group,and they were further increased after lipopolysaccharide (LPS) stimulation for 24 hours.AGM could effectively reduce the levels of TNF-α and IL-6 in Kupffer cells [TNF-α (ng/L)256.6 ± 5.6 vs.465.5 ± 5.2,IL-6 (ng/L)1 185.5 ± 64.4 vs.2 018.8 ± 53.2,both P ＜ 0.01],and also decreased the mRNA expressions of TNF-α and IL-6 [TNF-α mRNA (2-△△Ct)7.2±0.4 vs.13.5±0.4,IL-6 mRNA (2-△△Ct)13.2±0.7 vs.21.3 ± 1.6,both P ＜ 0.01].Conclusion Agmatine can reduce trauma-induced acute hepatic injury via suppression of cytokines release in Kupffer cells,and can ameliorate the liver function.