Mechanism of oxygenation of pancreas during preservation by a two-layer (Euro-Collins' solution/perfluorochemical) cold-storage method

To clarify the mechanism of oxygenation of the pancreas during preservation by two-layer (Euro-Collins' solution [EC]/perfluorochemical [PFC]) cold-storage method, the pancreas viability in the canine model of the pancreatic autotransplantation and tissue concentration of adenosine triphosphate were examined after 24-hr preservation by original and modified two-layer methods with respect to the position of the pancreas and oxygen bubbling into the PFC. Namely, the pancreas was in EC and on the surface of PFC with (group 1, original method) or without (group 2) oxygen bubbling into PFC. The pancreas was floated in EC with oxygen bubbling into PFC (group 3); compared with simple cold storage of the pancreas in EC (group 4); and nonpreserved pancreas (control, group 5). The preserved pancreas grafts by each method functioned immediately after transplantation and maintained normoglycemia for at least 5 days except that 1 of 5 dogs in group 4 died of a cause unrelated to the pancreas graft. The functional success rates of groups 1, 2, 3, 4, and 5 were 100%, 100%, 100%, 80%, and 100%, respectively. It was clear that mitochondrial function was well-preserved during 24-hr preservation regardless of the preservation method. In the condition that the mitochondrial function is well-preserved the tissue concentration of ATP was mostly dependent on the tissue oxygenation. The tissue concentration of ATP of group 1, 7.92 +/- 1.06 mumol/g dry weight, was significantly higher than that of nonpreserved pancreas (group 5), 4.44 +/- 0.49 mumol/g dry weight (P less than 0.01). It was apparent that the two-layer method was excellent to supply oxygen to the pancreas and maintain high ATP concentration of the pancreas during preservation. In contrast, ATP concentration of the pancreas of group 2 was 1.83 +/- 0.30 mumol/g dry weight, and there was no significant difference between group 2 and group 4, 1.19 +/- 0.33 mumol/g dry weight, thus meaning that PFC was biologically inert without oxygenation. In addition, when the pancreas was not contacted with oxygenated PFC and floated in EC (group 3) ATP concentration of the pancreas, 2.24 +/- 0.90 mumol/g dry weight, was significantly lower than group 1 (P less than 0.01), and no significant different was found as compared to groups 2 and 4. It was essential that the pancreas was contacted with oxygenated PFC to maintain high ATP tissue concentration during preservation by the two-layer method.(ABSTRACT TRUNCATED AT 400 WORDS)