Biliary immunoreactive trypsin in man.

Small, but significant amounts of immunoreactive trypsin/trypsinogen (IRT) are excreted in bile, obtained via percutaneous transhepatic catheter in patients with complete distal bile duct obstruction, and thus uncontaminated with pancreatic juice. The major serum proteolytic enzyme inhibitors alpha 2-macroglobulin and alpha 1-antitrypsin are also present in very small amounts in bile. The bile-to-serum ratios of these inhibitors are much lower (approximately two orders of magnitude) than that for IRT. The role of these inhibitors and their relative importance in biliary proteolytic enzyme inhibition is unknown.