Skip Navigation

Publication Detail

Title: Differential disposition of chenodeoxycholic acid versus taurocholic acid in response to acute troglitazone exposure in rat hepatocytes.

Authors: Marion, Tracy L; Perry, Cassandra H; St Claire 3rd, Robert L; Yue, Wei; Brouwer, Kim L R

Published In Toxicol Sci, (2011 Apr)

Abstract: Inhibition of bile acid (BA) transport may contribute to the hepatotoxicity of troglitazone (TRO), a peroxisome proliferator-activated receptor gamma agonist. Typically, studies use taurocholic acid (TCA) as a model substrate to investigate effects of xenobiotics on BA disposition. However, TRO may differentially affect the transport of individual BAs, potentially causing hepatocyte accumulation of more cytotoxic BAs. The effects of TRO on the disposition of [(14)C]-labeled chenodeoxycholic acid ([(14)C]CDCA), an unconjugated cytotoxic BA, were determined in suspended hepatocytes and sandwich-cultured hepatocytes (SCH) from rats. (E)-3-[[[3-[2-(7-chloro-2-quinolinyl)ethenyl]phenyl][[3-(dimethylamino)-3-oxopropyl]thio]methyl]thio]-propanoic acid (MK571), a multidrug resistance-associated protein (MRP) inhibitor, was included to evaluate involvement of MRPs in CDCA disposition. Accumulation in cells + bile of total [(14)C]CDCA species in SCH was sixfold greater than [(3)H]TCA and unaffected by 1 and 10ýýM TRO; 100ýýM TRO and 50ýýM MK571 ablated biliary excretion and significantly increased intracellular accumulation of total [(14)C]CDCA species. Results were similar in Mrp2-deficient TR(-) rat hepatocytes. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that taurine- and glycine-conjugated CDCA, in addition to unconjugated CDCA, accumulated in hepatocytes during the 10-min incubation. In suspended rat hepatocytes, initial [(14)C]CDCA uptake was primarily Na(+)-independent, whereas initial [(3)H]TCA uptake was primarily Na(+)-dependent; TRO and MK571 decreased [(14)C]CDCA uptake to a lesser extent than [(3)H]TCA. Unexpectedly, MK571 inhibited Na(+)-taurocholate cotransporting polypeptide and bile salt export pump. Differential effects on uptake and efflux of individual BAs may contribute to TRO hepatotoxicity. Although TCA is the prototypic BA used to investigate the effects of xenobiotics on BA transport, it may not be reflective of other BAs.

PubMed ID: 21262925 Exiting the NIEHS site

MeSH Terms: ATP-Binding Cassette Transporters/antagonists & inhibitors; ATP-Binding Cassette Transporters/genetics; Animals; Biological Transport; Carbon Radioisotopes; Cells, Cultured; Chenodeoxycholic Acid/metabolism*; Chromans/toxicity*; Chromatography, High Pressure Liquid; Drug-Induced Liver Injury/etiology; Drug-Induced Liver Injury/metabolism; Hepatocytes/drug effects*; Hepatocytes/metabolism; Male; PPAR gamma/agonists*; Propionates/pharmacology; Quinolines/pharmacology; Rats; Rats, Wistar; Tandem Mass Spectrometry; Taurocholic Acid/metabolism*; Thiazolidinediones/toxicity*

Back
to Top