Effects of dietary pectin and fat on the small intestinal contents and exocrine pancreas of rats.

The effects of dietary pectin and fat level on digestive enzyme activities in the pancreas and small intestine and on intestinal bile acid levels were investigated. In unfed rats, dietary pectin did not influence the pancreatic enzymes studied, but a higher level of corn oil in the diet lowered the amylase activity in the pancreas, increased pancreatic lipase activity and slightly lowered the chymotrypsin and trypsin activities. Diet did not change the dry weight of the pancreas. In the fed rats, dietary pectin increased the dry weight of the small gut wash plus the mucosal scraping. Dietary pectin increased the small intestinal lipase and chymotrypsin levels and at the low level of fat only, increased amylase and trypsin activities in the small intestine of fed rats. Intestinal lipase levels were higher and amylase levels lower in rats consuming the high level of corn oil. These results indicate that changes in dietary fat level led to changes in the amylase and lipase content of secreted pancreatic juice and that differences in absorption associated with diets containing pectin could be the result of increased material in the small intestine.