Effects of bile acids on mucus secretion in the dog colon.

The effects of unconjugated bile acids on colonic mucus production have been studied in the dog. Isolated segments of both ascending and descending colon were simultaneously perfused with either chenodeoxycholic, deoxycholic or cholic acid and the mucus production estimated from the total hexose output. Each bile acid produced a significant increase in mucus output in both the right and left colonic segments. There were no differences between the right and left colon in terms of mucus output for any of the bile acids studied. Deoxycholic had a greater effect than chenodeoxycholic which had a greater effect than cholic acid in colonic mucus production. Further, these effects on mucus secretion were completely reversible. In diarrhoea associated with disease or resection of the ileum, the effect of bile acids on mucus secretion may be as important as their effects on the inhibition of water and electrolyte absorption.