Taurolithocholic acid-d5 (TLCA-d5) is intended for use as an internal standard for the quantification of TLCA by GC- or LC-MS. TLCA is a taurine-conjugated form of the secondary bile acid lithocholic acid .1 TLCA (75 μM) increases caspase-3 and -7 activity in Hep3B cells transfected with sodium taurocholate cotransporting peptide (NTCP), but not nontransfected Hep3B cells.2 It has been used to induce cholestasis in ex vivo and in vivo animal models of hepatocellular cholestasis.3,4 Serum levels of TLCA increase approximately 5-fold within two hours during an oral lipid tolerance test in humans.1
1.Schmid, A., Neumann, H., Karrasch, T., et al.Bile acid metabolome after an oral lipid tolerance test by liquid chromatography-tandem mass spectrometry (LC-MS/MS)PLoS One11(2)e0148869(2016) 2.Rust, C., Wild, N., Bernt, C., et al.Bile acid-induced apoptosis in hepatocytes is caspase-6-dependentJ. Biol. Chem.284(5)2908-2916(2009) 3.Denk, G.U., Maitz, S., Wimmer, R., et al.Conjugation is essential for the anticholestatic effect of NorUrsodeoxycholic acid in taurolithocholic acid-induced cholestasis in rat liverHepatology52(5)1758-1768(2010) 4.Javitt, N.B.Cholestasis in rats induced by taurolithocholateNature210(5042)1262-1263(1966)