The elimination of trypsin--alpha-macroglobulin complexes from the blood circulation in pigs during acute pancreatitis and after massive intravenous trypsin infusion.

The elimination from plasma of intravenously injected 125I-labelled trypsin-alpha-macroglobulin complexes was studied in both healthy and diseased, anaesthetized pigs. The t1/2 for the 125I-labelled complexes was 5-10 min in healthy pigs as well as in two groups of pancreatitis pigs. Pre-loading of the eliminating capacity by massive intravenous trypsin infusion, raised t1/2 to 80-100 min. Thus, the eliminating capacity seems to be saturable. Elimination of the complexes from the blood circulation occurred within 4-5 h. Even massive intravenous amounts of trypsin-alpha-macroglobulin complexes gave no demonstrable complement or kinin activation. Neither were other deleterious effects seen during the experiment or during 7 days of follow-up. The results indicate that treatment of acute pancreatitis in humans with alpha 2-macroglobulin might be possible, without any danger arising from the protease-alpha 2-macroglobulin complexes formed.