RESUMO
Objective To explore the expression and significance of uncoupling protein (UCP)2in rats models of acute liver failure (ALF). Methods Thirty-six healthy male SD rats were randomly divided into normal control group and model group, and the model group was divided into 5 subgroups:6, 12, 24, 36 and 48 hours sub groups with 6 rats in each sub group. The rat model of ALF was established by intraperitoneal injections of D-galactosamine (D-Gal) and lipopolysaccharide (LPS).Sections of liver tissue were stained with hematoxylin and eosin and observed under optical microscope.UCP2 and UCP2 mRNA in rat liver were determined at different time points with immunohistochemical method and reverse transcription-polymerase chain reaction ( RT-PCR ),respectively. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and malondialdehyde (MDA) concentration in the liver tissues were analyzed at the same time points.Comparisons among all the experimental groups were done by SNK test. Results Infiltration of inflammatory cells and necrosis of hepatic cells were marked in model group,and ALT, AST and MDA in model group were significantly higher than those in control group [(24. 0 ± 2. 0) U/L, (82. 3±16. 9) U/L, (2. 55±0. 22)μmol/g] at all time points. And they reached a peak at 24 h [(8346. 7±1363. 1) U/L, (9766. 7±1274. 1) U/L, (8. 34±1. 13) μmol/g; all P<0. 05]. UCP2 and UCP2 mRNA expressed scarcely in the liver tissues of control group, while increased markedly from 6 to 48 hours after D-Gal/LPS challenge in model group (P<0. 05). They both reached a peak at 24 h. And the discrepancy between consecutive experimental group had statistical significance ( P < 0. 05).Conclusions The rat model of ALF was established successfully by intraperitoneal injections of D-gal and LPS. The expression levels of UCP2 mRNA and UCP2 are consistent with the extent of liver injury and the level of oxidative stress in the rat model of ALF.