taurochenodeoxycholate

Taurochenodeoxycholate, abbreviated TCDCA, is the taurine conjugate of chenodeoxycholic acid, one of the primary bile acids produced in the liver. It forms when chenodeoxycholate is conjugated with taurine via the action of bile acid-CoA:amino acid N-acyltransferase, producing a water-soluble bile salt that participates in bile formation and fat digestion.

In humans and many mammals, chenodeoxycholic acid can be conjugated with glycine or taurine; the resulting glyco- and tauro-conjugates are secreted into bile. Taurochenodeoxycholate is thus a major taurine-conjugated bile salt present in bile and can reach the intestine after gallbladder release. As a bile acid, it contributes to the formation of mixed micelles that solubilize dietary lipids, enabling their digestion and absorption.

Beyond its digestive role, bile acids including TCDCA also act as signaling molecules that influence metabolic pathways through receptors such as FXR and TGR5. The composition and pool size of conjugated bile acids can be altered in liver or biliary disorders, reflecting changes in bile acid synthesis, conjugation, and secretion.

Clinically, alterations in taurochenodeoxycholate levels can be observed in cholestasis and other hepatobiliary diseases. Bile acid profiling, often by LC-MS techniques, helps assess liver function and biliary flow. Taurochenodeoxycholate is typically considered alongside other conjugated and unconjugated bile acids in diagnostic contexts.