Beneficial effects of adenosine triphosphate-sensitive K^+ channel opener on liver ischemia/reperfusion injury

AIM:To investigate the effect of diazoxide administration on liver ischemia/reperfusion injury.METHODS:Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from the medium and left anterior lateral segments for 1 h under mechanical ventilation.They were divided into 3 groups:Control Group,rats submitted to liver manipulation,Saline Group,rats received saline,and Diazoxide Group,rats received intravenous injection diazoxide(3.5 mg/kg) 15 min before liver reperfusion.4 h and 24 h after reperfusion,blood was collected for determination of aspartate transaminase(AST),alanine transaminase(ALT),tumor necrosis factor(TNF-α),interleukin-6(IL-6),interleukin-10(IL-10),nitrite/nitrate,creatinine and tumor growth factor-β1(TGF-β1).Liver tissues were assembled for mitochondrial oxidation and phosphorylation,malondialdehyde(MDA) content,and histologic analysis.Pulmonary vascular permeability and myeloperoxidase(MPO) were also determined.RESULTS:Four hours after reperfusion the diazoxide group presented with significant reduction of AST(2009 ± 257 U/L vs 3523 ± 424 U/L,P = 0.005); ALT(1794 ± 295 U/L vs 3316 ± 413 U/L,P = 0.005); TNF-α(17 ± 9 pg/mL vs 152 ± 43 pg/mL,P = 0.013; IL-6(62 ± 18 pg/mL vs 281 ± 92 pg/mL); IL-10(40 ± 9 pg/mL vs 78 ± 10 pg/mL P = 0.03),and nitrite/nitrate(3.8 ± 0.9 μmol/L vs 10.2 ± 2.4 μmol/L,P = 0.025) when compared to the saline group.A significant reduction in liver mitochondrial dysfunction was observed in the diazoxide group compared to the saline group(P < 0.05).No differences in liver MDA content,serum creatinine,pulmonary vascular permeability and MPO activity were observed between groups.Twenty four hours after reperfusion the diazoxide group showed a reduction of AST(495 ± 78 U/L vs 978 ± 192 U/L,P = 0.032); ALT(335 ± 59 U/L vs 742 ± 182 U/L,P = 0.048),and TGF-β1(11 ± 1 ng/mL vs 17 ± 0.5 ng/mL,P = 0.004) serum levels when compared to the saline group.The control group did not present alterations when compared to the diazoxide and saline groups.CONCLUSION:Diazoxide maintains liver mitochondrial function,increases liver tolerance to ischemia/reperfusion injury,and reduces the systemic inflammatory response.These effects require further evaluation for using in a clinical setting.