Continuous infusion of N-acetylcysteine reduces liver warm ischaemia–reperfusion injury

Abstract

Abstract Background N-acetylcysteine (NAC) may modulate the initial phase (less than 2 h) of liver warm ischaemia–reperfusion (IR) injury but its effect on the late phase remains unclear. The present study investigated the role of NAC during the early and late phases in a rabbit lobar IR model. Methods Liver ischaemia was induced by inflow occlusion to the median and left liver lobes for 60 min, followed by 7 h of reperfusion. In the NAC group (n = 6), NAC was administered intravenously at 150 mg per kg over the 15 min before reperfusion and maintained at 10 mg per kg per h during reperfusion. In the IR group (n = 6), 20 ml 5 per cent dextrose was infused over the 15 min before reperfusion and continued at a rate of 10 ml/h. Animals in a sham operation group (n = 6) underwent laparotomy but no liver ischaemia. All animals were killed at the end of the experiment. Results Intracellular tissue oxygenation was improved after the second hour of reperfusion in animals treated with NAC compared with that in the IR group (P = 0·023). Hepatic microcirculation improved after 5 h of reperfusion (P = 0·036) and liver injury was reduced after 5 h, as indicated by alanine aminotransferase activity (P = 0·007) and indocyanine green clearance (uptake, P = 0·001; excretion, P = 0·032). Conclusion The main protective effect of NAC becomes apparent 5 h after hepatic ischaemic injury.