Protease activation following reperfusion of porcine pancreatic allografts.
To study the degree of protease activation at reperfusion of a pancreatic allograft after cold storage for 24 hr, 18 porcine whole-organ pancreaticoduodenal allograft transplantations were performed. Twelve grafts were flushed with and stored in Perfadex. In six of these, a hyperosmotic salt solution was injected into the graft aorta at reperfusion. Six grafts were flushed and stored in UW solution. Eleven of twelve grafts in the Perfadex groups were functioning on the first postoperative day, compared with one of six in the UW solution group. There was a significantly more pronounced protease activation among grafts stored in UW solution than in the other groups, with a subsequent breakthrough of the local protease protection barrier made up of protease inhibitors. In surviving pigs (n = 14), biochemical signs of protease activation evolved in plasma, including formation of trypsin-protease inhibitor complexes, a decline in C3 and kininogen levels, and a decline in functionally active alpha 2-macroglobulin, functionally active antithrombin III, and plasma kallikrein inhibitory activity. These biochemical signs of pancreatitis correlated with a deteriorated graft function on the second postoperative day, indicating that graft tissue damage occurred due to protease activation.