Immunoreactive pancreatic secretory trypsin inhibitor in gastrointestinal mucosa.

This study has shown that ileal and colonic mucosa contained roughly 1.2 microg/g of irPSTI. irPSTI from gastrointestinal mucosa eluted in a similar way to that of native PSTI after chromatographic separation and inhibited trypsin in a 1-1 molar way. The PSTI immunoreactive material was localized in the Paneth cells and the goblet cells in the small and large intestine. In normal gastric mucosa it was found in the foveolar cells while the acid and pepsinogen producing cells lacked PSTI immunoreactive material. In gastric mucosa with intestinal metaplasia a marked deficiency of PSTI was found. These findings indicate that gastrointestinal mucosa could be an additional source of irPSTI. Further studies are needed to elucidate if PSTI is involved in the defence of the gastrointestinal mucosa.