F2 -Isoprostanes and 2-Arachidonylglycerol as Biomarkers of Lipid Peroxidation in Pigs with Hepatic Ischemia/Reperfusion Injury

Background In the present study, we examined the changes of F2 -isoprostanes (non-cyclooxygenase-derived prostanoids), endocannabinoids (2-arachidonylglycerol; 2-AG, arachidoylethanolamide; AEA), and malondialdehyde (MDA: a conventional index of lipid peroxidation) in a porcine warm hepatic ischemia/reperfusion (I/R) model to evaluate the usefulness of each parameter as a marker of lipid peroxidation. Methods Five female pigs weighing 20 to 22 kg were used in this experiment. Total liver ischemia was achieved by clamping the hepatic pedicle. To prevent splanchnic congestion during occlusion of the portal vein, a portocaval shunt was created with a Dacron graft. After 90 min of ischemia, the liver was reperfused for 120 min. We measured the plasma levels of four markers (F2 -isoprostanes, 2-AG, AEA, and MDA) from a viewpoint of whether it is useful as a sensitive marker of lipid peroxidation. Results Based on statistical analysis using repeated-measures ANOVA, F2 -isoprostanes demonstrated the most significant changes and were considered to be a highly sensitive marker ( P = 0.0001). 2-AG showed less prominent but significant changes ( P = 0.0286), followed by MDA ( P = 0.0310). However, AEA did not show statistically significant changes over time. The pattern of change in the serum transaminase levels, a classic marker of liver damage, as well as the histologic changes, resembled the profile of F2 -isoprostanes, 2-AG, and MDA. Conclusions F2 -isoprostanes and 2-AG may be useful as markers of oxidative stress in hepatic I/R injury.