title: Demonstration of human pancreatic anionic trypsinogen in normal serum by radioimmunoassay.
abstract: A specific radioimmunoassay for human pancreatic anionic trypsin has been developed. The trypsin employed as radioiodinated tracer in the assay was inactivated with tosyl-L-lysine chloromethyl ketone in order to prevent binding of the tracer to the serum inhibitors alpha1-antitrypsin and alpha2-macroglobulin. A normal serum level of immunoreactive anionic trypsin of 5.45 ng/ml was determined. The results of experiments in which serum was fractionated by Sephadex G-200 gel filtration suggest that essentially all of the immunoreactive material in normal human serum is trypsinogen. This finding implies that a small fraction of the zymogens synthesized in the pancreas are released directly into the circulation.
mesh_terms: D000838:Anions; D006801:Humans; D011863:Radioimmunoassay; D014362:Trypsinogen / Q000097:blood*
chemical_list: D000838:Anions; D014362:Trypsinogen