Reduced oxidative stress during acellular reperfusion of the rat liver after hypothermic oscillating perfusion

Background. ATP resynthesis during reperfusion after liver preservation has been shown to be well correlated with the function of transplanted grafts. Nevertheless, the advantages of a cellular energy charge loading during th e preservation period are yet not fully understood. This study evaluates th e effects of different nucleotide levels at the end of preservation on meta bolic changes and oxidative stress during reperfusion. Methods. Two experimental groups were chosen reflecting different energy ch arge states after preservation: static cold storage for 10 hr and hypotherm ic oxygenated oscillating perfusion for 10 hr. In both experimental groups, normothermic ex vivo acellular reperfusion over 40 min was performed. A th ird group consisted of nonpreserved livers similarly reperfused for 40 min. Superoxide formation was detected by the superoxide dismutase inhibitable reduction of ferricytochrome c added to the normothermic perfusate. Results. Superoxide formation and lipid peroxidation malondialdehyde were s ignificantly lower during reperfusion after the energy charge loading befor e reperfusion by the hypothermic oscillating perfusion technique. However, oxygen radical formation, liver cell injury (lactate dehydrogenase [LDH] re lease), and TNF alpha release were significantly higher in energy charge-de pleted groups (nonpreserved and cold stored livers). Conclusions. Hypothermic oscillating oxygenated perfusion led to the elevat ed energy charge during preservation and led to reduced oxygen radical form ation as well as less lipid peroxidation during reperfusion, in contrast to cold stored livers and nonpreserved livers. This suggests a correlation be tween the energy charge before reperfusion and oxygen radical formation as well as liver injury at reperfusion.