Nitric oxide level profile in human liver transplantation.

The aim of this study was to monitor nitric oxide blood levels at various times intraoperatively and following liver transplantation in humans. Nitric oxide production was assessed directly as circulating nitrosyl-hemoglobin adducts by electron paramagnetic resonance spectroscopy in 22 patients undergoing orthotopic liver transplantation. Two significant peaks in nitrosylhemoglobin levels were detected at 5 and 60 min after reperfusion (5.02 +/- 3.33 arbitrary units and 5.75 +/- 4.19, respectively, vs 3.33 +/- 2.28 under basal state; P < 0.05 for both comparisons). Postoperative nitrosyl-hemoglobin levels remained elevated, up to 5.42 +/- 0.89 arbitrary units (P < 0.05 vs basal values). Neither soluble intercellular adhesion molecule-1 or soluble endothelial-leukocyte adhesion molecule concentrations were altered intraoperatively. Only the former was significantly raised after transplantation. Neutrophil elastase levels showed an early increase and remained high throughout surgery, returning to basal values after transplantation. No correlations were found among studied parameters. These data suggest that nitric oxide may play a role in ischemia-reperfusion phases in human liver transplantation. Mechanisms other than leukocyte-endothelial adhesion and neutrophil activation seem to affect nitric oxide production under these conditions.