Gaseous oxygen for hypothermic preservation of predamaged liver grafts: Fuel to cellular homeostasis or radical tissue alteration?

Gaseous persufflation with molecular oxygen during cold storage has recentl y been discussed as an adjunct in the preservation of predamaged livers fro m non-heart-beating donors. in this study, the actual importance of an anti oxidant medication prior to oxygen persufflation was investigated for the f irst time. Rat livers were excised 60 min after cardiac arrest of the donor , flushed with UW, and stored at 4 degrees C for 24 h. Gaseous oxygen, appl ied to the livers during the storage period via the caval vein at a pressur e limited to 18 mm Pig, was only effective in improving hepatic viability u pon reperfusion when antioxidants (superoxide dismutase (SOD) or n-acetylcy steine) were added to the UW rinse solution. Either drug prevented an incre ase in free radical mediated lipid peroxidation. Acetylcysteine but not SOD also counteracted the phosphorylation of I kappa b and thus the transcript ional activation of NF kappa b. Poor results after oxygen persufflation wit hout antioxidants may hence be explained by concomitant free radical induce d tissue alterations upon introduction of molecular oxygen into ischemicall y predamaged organs. (C) 2000 Academic Press.