Quantification of biliary excretion and sinusoidal excretion of 5(6)-carboxy-2 ',7 '-dichlorofluorescein (CDF) in cultured hepatocytes isolated from Sprague Dawley, Wistar and Mrp2-deficient Wistar (TR-) rats

L. C. J. Ellis*, M. H. Grant, Gabrielle Margaret Hawksworth, R. J. Weaver

*Corresponding author for this work

Research output: Contribution to journalArticle

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Abstract

Hepatic efflux of drug candidates is an important issue in pre-clinical drug development. Here we utilise a method which quantifies and distinguishes efflux of drugs at the canalicular and sinusoidal membranes in rat hepatocyte cultures. Bi-phasic kinetics of transport of 5(6)-carboxydichlorofluorescein (CDF) at the canalicular membrane was demonstrated in Sprague Dawley (SD) and Wistar (W) rat hepatocytes. The high affinity component (Km = 3.2 +/- 0.8 mu M (SD), 9.0 +/- 3.1 mu M (W)) was attributed to Mrp2-mediated transport, the low affinity component (Km = 192.1 +/- 291.5 mu M (SD), 69.2 +/- 36.2 mu M (W)) may be attributed to transport involving a separate Mrp2 binding site. Data from membranes (Hill coefficient (h) = 2.0 +/- 0.5) and vesicles (h = 1.6 +/- 0.2) expressing Mrp2 and from SD (h = 1.6 +/- 0.4) and Wistar (h = 4.0 +/- 0.6) hepatocytes suggests transport involves more than one binding site. In TR- hepatocytes, CDF efflux was predominantly over the sinusoidal membrane (Km = 100.7 +/- 36.0 mu M), consistent with low abcc2 (Mrp2) expression and compensatory increase in abcc3 (Mrp3) expression. This report shows the potential of using this in vitro method to model changes in biliary excretion due to alterations in transporter expression. (C) 2014 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)1165-1175
Number of pages11
JournalToxicology in Vitro
Volume28
Issue number6
Early online date4 Jun 2014
DOIs
Publication statusPublished - Sep 2014

Keywords

  • primary rat hepatocytes
  • membranes and vesicles expressing rat
  • Mrp2
  • drug transporters
  • canalicular efflux
  • sinusoidal efflux
  • Dubin-Johnson syndrome
  • collagen-sandwich configuration
  • canalicular networks
  • transport protein
  • expression
  • drug
  • MRP2
  • membrane
  • liver
  • disposition

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