Effect of bile acids on electrical properties of rat colon: evaluation of an in-vitro model for secretion.

A preparation of rat colon mucosa has been evaluated as a useful model to study effects of bile acids on the changes in short-circuit current and transmural electrical potential difference (pd) which others have associated with alterations in electrolyte transport. Using this preparation, it was found that bile acids were effective in increasing short-circuit current and pd when applied to the serosal, but not the mucosal, surface of the tissue. Furthermore, taurine-conjugated cholic acid, which has no demonstrable effect on the colon in vivo, was found to increase short-circuit current and pd significantly in the in-vitro preparation. These data indicate the limitations of the in-vitro model in studying the mechanism of bile acid-stimulated intestinal secretion.