INFLUENCE OF DEHYDROCHOLIC ACID ON THE SECRETION OF BILE-ACIDS AND BILIARY LIPIDS IN RATS

This study investigated the influence of dehydrocholic acid (DHCA) infusion on the secretion of endogenous bile acids, and biliary lipids in rats in an attempt to explain the reduction of biliary lipid secretion associated with DHCA infusion. DHCA increased bile flow and the bile acids produced during the infusion were composed of three hydroxy-oxo metabolites (83-93%), and cholic acid (6-14%). Very little DHCA was secreted unchanged (<2%). The secretions of all the endogenous biliary bile acids were diminished within 30-60 min of infusion. DHCA furthermore reduced the secretion of exogenous cholic acid when co-infused with DHCA. Phospholipid secretion declined to an undetectable amount and cholesterol declined to 10% of the base value by the end of the infusion. The reduction of biliary lipid secretion during DHCA infusion was attributed to the diminished secretion of endogenous bile acids. These data show that DHCA infusion induces choleresis associated with reduced secretion of endogenous and/or exogenous biliary components.