BACKGROUND/AIMS: High levels of hydrogen peroxide (H2O2) are observed during inflammatory and ischemic states of the liver and usually lead to cellular dysfunction and cytotoxicity. Recently, it has been reported that erythropoietin and mitochondrial K (ATP) channel openers have a protective effect via a pharmacological preconditioning action during ischemia reperfusion injury of the liver and heart. However, it remains unclear as to whether K (ATP) channel blockers can reduce the protective effect of erythropoietin in the H2O2-induced injury of hepatocytes. METHODS: To determine whether erythropoietin treatment decreases H2O2-induced toxicity, we used human hepatocyte cell line Hep3B for assays. Cells were pretreated with different dosages of erythropoietin (0.1-1-10-50 IU/ml) 2 h before H2O2 application. For determination of effects of blockage of mitochondrial K (ATP) channels during erythropoietin treatment, glibenclamide treatment was applied to the medium 2 h before H2O2 toxicity. Cell number, lactate dehydrogenase and caspase- 3 levels were measured in erythropoietin, glibenclamide and/or H2O2-treated groups. RESULTS: Erythropoietin treatment significantly increased cell number at the 24th and 48th h compared to the control group. H2O2 application induced apoptosis and lactate dehydrogenase release from Hep3B cells and decreased cell number. Erythropoietin prevents H2O2 toxicity in hepatocytes. The K channel inhibitor glibenclamide decreased the cytoproliferative and cytoprotective effect of erythropoietin during H2O2 toxicity of Hep3B cells. CONCLUSIONS: Erythropoietin treatment may be considered as a therapeutic agent during oxidative injuries of hepatocytes and its cytoprotective effect is abolished by glibenclamide.
BACKGROUND/AIMS: High levels of hydrogen peroxide (H2O2) are observed during inflammatory and ischemic states of the liver and usually lead to cellular dysfunction and cytotoxicity. Recently, it has been reported that erythropoietin and mitochondrial K (ATP) channel openers have a protective effect via a pharmacological preconditioning action during ischemia reperfusion injury of the liver and heart. However, it remains unclear as to whether K (ATP) channel blockers can reduce the protective effect of erythropoietin in the H2O2-induced injury of hepatocytes. METHODS: To determine whether erythropoietin treatment decreases H2O2-induced toxicity, we used human hepatocyte cell line Hep3B for assays. Cells were pretreated with different dosages of erythropoietin (0.1-1-10-50 IU/ml) 2 h before H2O2 application. For determination of effects of blockage of mitochondrial K (ATP) channels during erythropoietin treatment, glibenclamide treatment was applied to the medium 2 h before H2O2toxicity. Cell number, lactate dehydrogenase and caspase- 3 levels were measured in erythropoietin, glibenclamide and/or H2O2-treated groups. RESULTS:Erythropoietin treatment significantly increased cell number at the 24th and 48th h compared to the control group. H2O2 application induced apoptosis and lactate dehydrogenase release from Hep3B cells and decreased cell number. Erythropoietin prevents H2O2toxicity in hepatocytes. The K channel inhibitor glibenclamide decreased the cytoproliferative and cytoprotective effect of erythropoietin during H2O2toxicity of Hep3B cells. CONCLUSIONS:Erythropoietin treatment may be considered as a therapeutic agent during oxidative injuries of hepatocytes and its cytoprotective effect is abolished by glibenclamide.
Authors: Daniel Seehofer; Ulf P Neumann; Anja Schirmeier; Jessica Carter; Si-Young Ria Cho; Andri Lederer; Nada Rayes; Michael D Menger; Andreas K Nüssler; Peter Neuhaus Journal: Langenbecks Arch Surg Date: 2008-02-27 Impact factor: 3.445