Studies on pancreatic secretory trypsin inhibitor in normal and diseased gastrointestinal tract

The presence of immunoreactive pancreatic secretory trypsin inhibitor (irPSTI) was studied using an immunohistochemical method in normal and diseased gall bladder and normal and neoplastic colonic mucosa. Normal and inflammatory gall bladder mucosa did not stain for irPSTI. Neoplastic gall bldder mucosa showed positive staining for irPSTI, with a more pronounced staining in well rather than in poorly-diferentiated carcinoma. Normal colonic mucosa and adenomas, but rarely colonic carcinoma, stained positive for irPSTI. Furthermore, irPSTI, measured with an enzyme-linked immunosorbant assay (ELISA), revealed a jigher content in normal than in neoplastic colonic mucosa. These results indicatea prduction and consumption of PSTI in neoplastic tissue. IrPSTI was identified in most Brunner´s glands and the distribution was compared with that of ir Lysozyme and mucus. Using an ELISA and reverse transcriptase polymerase chain reaction ( RT-PCR), production and secretion of irPSTI was ascertained in human small intestine. The physiological function of PSTI may be epithelial cell protection.