ABSTRACT
ObjectiveTo investigate the effect of pretreatment with adenosine monophosphate-activated protein kinase (AMPK) agonist on rats with hepatic ischemia-reperfusion injury (HIRI) and the possible mechanism. MethodsA total of 54 healthy specific pathogen-free male Sprague-Dawley rats were randomly and equally divided into 5-aminimidazole-4-formamide nucleotide (AICAR) treatment group (experimental group), ischemia-reperfusion group (control group), and sham-operation group. Samples were collected at 12, 24, and 72 hours after hepatic ischemia-reperfusion surgery to measure the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil), tumor necrosis factor-α (TNFα), and interleukin-6 (IL-6) and the level of adenosine triphosphate (ATP) in the liver. HE staining was used to observe liver histological changes; quantitative real-time PCR was used to measure the relative mRNA expression levels of AMPK, mammalian target of rapamycin (mTOR), glucose transporter type 4 (GLUT4), and multidrug resistance-associated protein 2 (MRP2); Western blot was used to measure the protein expression levels of phosphorylated AMPK, phosphorylated mTOR, phosphorylated GLUT4, and MRP2. The repeated-measures analysis of variance was used for comparison between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsHE staining showed that the experimental group had milder liver injury than the control group at each time point. At 12, 24, and 72 hours after surgery, the control group had significantly higher serum levels of ALT, AST, TBil, IL-6, and TNFα than the experimental group and the sham-operation group, while the experimental group had significantly higher levels than the sham-operation group (all P＜005). At 12, 24, and 72 hours after surgery, the experimental group had a significantly higher level of ATP in liver tissue than the control group and the sham-operation group, and the control group had a significantly lower level than the sham-operation group (all P＜0.05). At 12, 24, and 72 hours after surgery, compared with the control group and the sham-operation group, the experimental group had significantly higher relative mRNA expression levels of AMPK, GLUT4, and MRP2 and protein expression levels of phosphorylated AMPK, phosphorylated GLUT4, and MRP2 (all P＜0.05); compared with the sham-operation group, the control group had significantly higher relative mRNA expression level of AMPK and protein expression level of phosphorylated AMPK, as well as significantly lower relative mRNA expression levels of GLUT4 and MRP2 and protein expression levels of phosphorylated GLUT4 and MRP2 (all P＜0.05). The experimental group had significantly lower relative mRNA expression level of mTOR and protein expression level of phosphorylated mTOR than the control group and the sham-operation group (all P＜0.05), and compared with the sham-operation group, the control group had significantly higher relative mRNA expression level of mTOR and protein expression level of phosphorylated mTOR (both P＜0.05). ConclusionAICAR pretreatment can activate the AMPK signaling pathway, improve energy metabolism pathway, alleviate liver inflammation, and thus reduce the severity of HIRI.