RECOVERY OF ADENOSINE-TRIPHOSPHATE TISSUE-LEVELS OF GRAFTS PRESERVED BY THE 2-LAYER METHOD AFTER REPERFUSION

Recovery of tissue adenosine triphosphate (ATP) levels after transplan tation is very important for graft survival. We examined whether the p ancreas grafts preserved by the two-layer method have the ability to s ynthesize ATP after reperfusion, and this is one of the mechanisms of action for the two-layer method in successful pancreas preservation. A fter preservation by the two-layer method using Euro-Collins' solution (EC) for 48 h (Group 1, n = 5) or simple cold storage in EC for 48 h (Group 2, n = 5), canine pancreas grafts were autotransplanted. In con trols (Group 3, n = 5), canine pancreas grafts were autotransplanted w ithout preservation. Graft viability was judged from graft survival af ter transplantation. Tissue adenine nucleotide concentrations were mea sured using high performance liquid chromatography after preservation, before reperfusion, and after 1 and 2 h of reperfusion. Graft surviva l rates were 5 of 5, 0 of 5, and 5 of 5, in Groups 1, 2, and 3, respec tively. However ATP tissue levels in Group 1 were significantly higher compared with those in Group 2 after preservation and before reperfus ion, respectively (10.95 +/- 1.52 vs. 2.75 +/- 0.33 and 2.90 +/- 0.51 vs. 2.03 +/- 0.68 mu mol/g dry weight, p < 0.01 and p < 0.05, respecti vely). Total tissue adenine nucleotide levels in Group 1 before reperf usion were 7.41 +/- 1.47 mu mol/g dry weight, and there was no signifi cant difference compared with Group 2, 6.64 +/- 2.23 mu mol/g dry weig ht. After reperfusion, there was no significant difference of ATP tiss ue levels between Groups 1 and 2 (4.07 +/- 1.18 vs. 4.48 +/- 1.32, not significant [NS]) after 1 h of reperfusion. However, after 2 h of rep erfusion, tissue ATP levels in Group 1 (6.71 +/- 1.19 mu mol/g dry wei ght) were significantly higher than were those in Group 2 (4.51 +/- 0. 51 mu mol/g dry weight, p < 0.01) and almost at the same levels as con trol (6.32 +/- 1.62 mu mol/g dry weight). It was clear that recovery o f ATP after reperfusion did not depend on the residual nucleotides poo l but on the ability of the pancreas graft to synthesize ATP after rep erfusion. We conclude that oxygenation of the pancreas graft during pr eservation by the two-layer method allows for ATP synthesis, which is essential in maintaining cellular integrity and leads to maintaining t he graft's ability to synthesize ATP promptly after reperfusion. This is one of the mechanisms of action of the two-layer method in successf ul pancreas preservation.