Fate of Pancreatic Enzymes During Gastrointestinal Transit

Abstract

In human studies, the fate of pancreatic enzymes during small-intestinal aboral transit has been a controversial issue. There are few data available. Borgstrom et al. [1] found that activities of all pancreatic enzymes decreased progressively and at similar rates as they moved from the proximal to the distal small bowel. In contrast, others have found in patients with ileostomies that the ileostomy effluent contained a large amount of trypsin and chymotrypsin activity [2, 3]. Recently we performed a study to determine how much pancreatic enzyme activity survives during small-intestinal aboral transit in healthy human volunteers by measuring the cumulative amount of lipase, trypsin, and amylase activities and lipase and trypsin immunoreactivities delivered postprandially (50 g, 400 ml semiliquid pure rice starch pudding) to the duodenum, mid-jejunum, and terminal ileum [4]. We found that as enzymes moved from the duodenum to the ileum 74% of amylase activity, 22% of trypsin activity, and 1% of lipase activity survived transit. Enzymatic activity and immunoreactivity of trypsin and lipase disappeared at different rates, suggesting that for these enzymes the sites of enzymatic activity and immunorecognition are not identical.