Adenine nucleotide metabolism of canine pancreas graft preserved by the two-layer (euro-collins' solution/perfluorochemical) method after reperfusion.

We have demonstrated that oxygenation of a pancreas during preservation by the two-layer method leads continued ATP production to maintain cellular integrity and produces an extended period of preserved pancreatic viability. In this study, we examined whether the pancreas grafts preserved by the two-layer method maintained adenine nucleotides pool as substrates for ATP synthesis before reperfusion and had the ability to synthesize ATP promptly and to recover energy charge potential (ECP) of the pancreas graft on reperfusion. After preservation by the two-layer cold storage method using EC for 48 hrs (group 1, n = 5), or simple cold storage in EC for 48 hrs (group 2, n = 5), canine pancreas grafts were autotransplanted. In control (group 3, n = 5), canine pancreas grafts were autotransplanted without preservation. Tissue adenine nucleotides concentrations were measured using high performance liquid chromatography (HPLC) before and after preservation, before reperfusion and after 1 hr- and 2 hr-reperfusion. Graft survival rates were 5/5, 0/5, and 5/5, in groups 1, 2 and 3, respectively. Total adenine nucleotides before reperfusion in group 1 was almost same levels as group 2 (7.41 +/- 1.47 vs 6.64 +/- 2.23 mumol/g dry weight, N.S.). Furthermore, ATP tissue levels in group 1 before reperfusion was 2.90 +/- 0.51 mumol/g dry weight and almost same levels as group 2 (2.03 +/- 0.68 mumol/g dry weight, N.S.). However, tissue ATP levels in group 1 after 2 hrs of reperfusion (6.71 +/- 1.19 mumol/g dry weight) were significantly higher than group 2 (4.51 +/- 0.51 mumol/g dry weight, P < 0.05), and almost same levels as control (group 3) (6.32 +/- 1.62 mumol/g dry weight, N.S.). In addition, ECP in group 1 and 3 (0.90 +/- 0.03 and 0.83 +/- 0.09, respectively) after 2 hr-reperfusion, were significantly higher than the value in group 2 (0.73 +/- 0.09, P < 0.01 and P < 0.05, respectively). It was clear that recovery of ATP on reperfusion was not depend on the residual nucleotides pool before reperfusion but the ability of the pancreas graft to recover tissue ATP levels and energy charge potential after reperfusion. We conclude that oxygenation of the pancreas graft during preservation by the two-layer method allows for ATP synthesis which is essential in maintaining cellular integrity and leads to maintain the graft's ability to recover ATP levels and energy charge potential promptly after reperfusion. Consequently the pancreas graft survives.