Immunohistochemical demonstration of pancreatic secretory proteins in human paneth cells

Gastro-intestinal mucosa obtained at surgical resection was studied by light microscopy using the unlabelled antibody enzyme method for immunohistochemical staining of lysozyme, anionic trypsin, cationic trypsin and pancreatic trypsin inhibitor (PSTI). Paneth cells, identified by their content of lysozyme, contained anionic trypsin, cationic trypsin and PSTI-like immunoreactivity. The demonstration of immunoreactive trypsin and immunoreactive PSTI is a further indication of the resemblance between Paneth cells and the pancreatic acinar cells.