Effect of small bowel bypass on the rat exocrine pancreas.

Biochemical, structural, and functional studies of the exocrine pancreas were performed in adult male Wistar rats over a 3-month period following a 90 per cent jejunoileal bypass or sham operation. The wet weight of the gland, its content in total protein and DNA, as well as its structural organization were similar in both groups. The enzyme content was globally reduced after bypass surgery. However, amylase was much more and earlier affected than lipase and chymotrypsinogen. In addition, zymogen granules diminished in size while lipid droplets deposited in acinar cells. Enzyme secretion stimulated or not by increasing concentrations of caerulein in vitro was generally reduced after intestinal bypass and approximately parallel to the depressed amount of enzymes in the pancreas. These findings suggest that jejunoileal bypass does not modify the size of the rat pancreas despite protein deficiency, but its enzymatic composition and secretory function is altered.