Glutathione and amino acid concentrations in human liver during short warm ischaemia and reperfusion: a pilot study

Glutathione is a major antioxidant, and, in the present study, we investigated whether a clinical model of short warm ischaemia and reperfusion of the human liver during surgery would influence glutathione and amino acid metabolism. Previous studies in humans have demonstrated that ischaemia and reperfusion in skeletal muscle for up to 120 min have no major effect on muscle glutathione concentrations. Liver ischaemia and reperfusion in animals have demonstrated diverging results concerning glutathione metabolism. In the present study, six patients with liver malignancies, undergoing liver resection during warm ischaemia, were included. Liver biopsies were obtained from healthy appearing liver tissue from both lobes before ischaemia and at maximal ischaemia, and from the remaining liver lobe after 5, 10, 15, 20, 25 and 30 min of reperfusion. The biopsies were analysed for glutathione, amino acids and lactate. Median ischaemia time was 28 (range, 15-36) min. Lactate increased 266% at maximal ischaemia (P<0.05). No alterations in glutathione concentrations or the redox status of glutathione (GSH/total glutathione) were observed. Glutamate decreased 22% (P<0.05) at maximal ischaemia and increased thereafter 72% at 30 min of reperfusion (P<0.05). Alanine increased 105% at maximal ischaemia (P<0.05) and was normalized during reperfusion. BCAAs (branched-chain amino acids) increased 67% at maximal ischaemia (P<0.05). In conclusion, short-time ischaemia and reperfusion in the human liver did not affect glutathione concentrations, whereas changes were observed in amino acid concentrations during both ischaemia and reperfusion.