Alpha 1-proteinase inhibitor in pure human pancreatic juice.

The presence of alpha 1-proteinase inhibitor (alpha 1-PI) in pure human pancreatic juice was demonstrated. Its concentration was measured using the radial immunodiffusion technique and compared to transferrin and albumin concentrations. In normal pancreatic juice the mean alpha 1-PI level (expressed in percent of total protein) was 0.21 +/- 0.02, whereas the mean levels of the two other serum proteins were 0.14 +/- 0.01 for transferrin and 0.90 +/- 0.07 for albumin. These levels increased significantly in the juice of patients with chronic calcifying pancreatitis. The serum origin of alpha 1-PI present in pancreatic juice was demonstrated by the good correlation existing between alpha 1-PI and albumin as well as between transferrin and albumin. In addition, in each case the alpha 1-PI level was found to be higher in secretin-stimulated juice than in cholecystokinin-stimulated juice. A similar pattern was also found for albumin.