Effects of nitrite on hepatic ischemia-reperfusion injury

Aim: Hepatic ischemia-reperfusion (IR) injury is a major complication associated with liver transplantation and surgery. The aim of this study is to investigate the cytoprotective effects of nitrite on hepatic IR injury. Methods: Groups were arranged as follows: control, sham, IR protocol (45 minutes ischemia, 5 hours reperfusion) and study groups administered with 4 different concentrations of sodium nitrite given 12 and 24 hours prior to protocol. After IR protocol, serum transaminase and lactate dehydrogenase (LDH) enzyme activities were determined as quantitative indices of liver damage. Malondialdehyde (MDA) levels, glutathione levels and antioxidant enzyme activities were determined in liver tissues of all study groups. Additionally inflammatory and tissue remodeling processes were investigated. Histological evaluations were also performed. Results: Serum transaminase and LDH activities were found to be increased in IR group compared to control group. Glutathione content and ratio of reduced glutathione to oxidized glutathione were found to be significantly decreased; oxidized glutathione and MDA content significantly increased in the IR group. All antioxidant enzyme activities were found to be lowered in IR group. TNF-alpha, IL-1 beta, IL-6, IL-8, IL-12, MMP-2 and MMP-9 levels were significantly increased in IR group compared to control group. In all nitrite administered groups, all parameters which were found to be changed with IR protocol were decreased to control levels depending on the concentration of nitrite. Total histological damage score at light microscope level was significantly higher in IR group. Nitrite improved histological damage scores by receiving similar scores with the control group. Conclusion: Based on findings, nitrite administration was found to have cytoprotective effects on hepatic IR injury.