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. 1996 Jul;118(6):1389–1396. doi: 10.1111/j.1476-5381.1996.tb15550.x

Transport and epithelial secretion of the cardiac glycoside, digoxin, by human intestinal epithelial (Caco-2) cells.

M E Cavet 1, M West 1, N L Simmons 1
PMCID: PMC1909679  PMID: 8832062

Abstract

1. Human intestinal epithelial Caco-2 cells have been used to investigate the transepithelial permeation of the cardiac glycoside, digoxin. 2. Transepithelial basal to apical [3H]-digoxin flux exceeds apical to basal flux, a net secretion of [3H]-digoxin being observed. At 200 microM digoxin, net secretory flux (Jnet) was 10.8 +/- 0.6 nmol cm-2 h-1. Maximal secretory flux (Jmax) of vinblastine was 1.3 +/- 0.1 nmol cm-2 h-1. Cellular uptake of digoxin was different across apical and basal cell boundaries. It was greatest across the basal surface at 1 microM, whereas at 200 microM, apical uptake exceeded basal uptake. 3. Net secretion of [3H]-digoxin was subject to inhibition by digitoxin and bufalin but was not inhibited by ouabain, convallatoxin, and strophanthidin (all 100 microM). Inhibition was due to both a decrease in Jb-a and an increase in Ja-b. Uptake of [3H]-digoxin at the apical surface was increased by digitoxin and bufalin. All cardiac glycosides decreased [3H]-digoxin uptake at the basal cell surface (except for 100 microM digitoxin). 4. The competitive P-glycoprotein inhibitors, verapamil (100 microM), nifedipine (50 microM) and vinblastine (50 microM) all abolished net secretion of [3H]-digoxin due to both a decrease in Jb-a and an increase in Ja-b. Cellular accumulation of [3H]-digoxin was also increased across both the apical and basal cell surfaces. I-Chloro-2,4,-dinitrobenzene (10 microM), a substrate for glutathione-S-transferase and subsequent ATP-dependent glutathione-S-conjugate secretion, failed to inhibit net secretion of [3H]-digoxin. The increase in absorptive permeability Pa-b (= Ja-b/Ca) and cellular [3H]-digoxin uptake upon P-glycoprotein inhibition, showed that the intestinal epithelium was rendered effectively impermeable by ATP-dependent extrusion at the apical surface. 5. A model for [3H]-digoxin secretion by the intestinal epithelium is likely to involve both diffusional uptake and Na(+)-K+ pump-mediated endocytosis, followed by active extrusion at the apical membrane.

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Selected References

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  1. Aiton J. F., Brown C. D., Ogden P., Simmons N. L. K+ transport in "tight' epithelial monolayers of MDCK cells. J Membr Biol. 1982;65(1-2):99–109. doi: 10.1007/BF01870473. [DOI] [PubMed] [Google Scholar]
  2. Artursson P., Karlsson J. Correlation between oral drug absorption in humans and apparent drug permeability coefficients in human intestinal epithelial (Caco-2) cells. Biochem Biophys Res Commun. 1991 Mar 29;175(3):880–885. doi: 10.1016/0006-291x(91)91647-u. [DOI] [PubMed] [Google Scholar]
  3. Awasthi S., Singhal S. S., Srivastava S. K., Zimniak P., Bajpai K. K., Saxena M., Sharma R., Ziller S. A., 3rd, Frenkel E. P., Singh S. V. Adenosine triphosphate-dependent transport of doxorubicin, daunomycin, and vinblastine in human tissues by a mechanism distinct from the P-glycoprotein. J Clin Invest. 1994 Mar;93(3):958–965. doi: 10.1172/JCI117102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Burton P. S., Conradi R. A., Hilgers A. R., Ho N. F. Evidence for a polarized efflux system for peptides in the apical membrane of Caco-2 cells. Biochem Biophys Res Commun. 1993 Feb 15;190(3):760–766. doi: 10.1006/bbrc.1993.1114. [DOI] [PubMed] [Google Scholar]
  5. Cordon-Cardo C., O'Brien J. P., Boccia J., Casals D., Bertino J. R., Melamed M. R. Expression of the multidrug resistance gene product (P-glycoprotein) in human normal and tumor tissues. J Histochem Cytochem. 1990 Sep;38(9):1277–1287. doi: 10.1177/38.9.1974900. [DOI] [PubMed] [Google Scholar]
  6. Damm K. H., Woermann C. The effect of probenecid on the in vitro absorption of cardiac glycosides. Eur J Pharmacol. 1974 Sep;28(1):157–163. doi: 10.1016/0014-2999(74)90127-7. [DOI] [PubMed] [Google Scholar]
  7. Dantzig A. H., Bergin L. Uptake of the cephalosporin, cephalexin, by a dipeptide transport carrier in the human intestinal cell line, Caco-2. Biochim Biophys Acta. 1990 Sep 7;1027(3):211–217. doi: 10.1016/0005-2736(90)90309-c. [DOI] [PubMed] [Google Scholar]
  8. De Lannoy I. A., Koren G., Klein J., Charuk J., Silverman M. Cyclosporin and quinidine inhibition of renal digoxin excretion: evidence for luminal secretion of digoxin. Am J Physiol. 1992 Oct;263(4 Pt 2):F613–F622. doi: 10.1152/ajprenal.1992.263.4.F613. [DOI] [PubMed] [Google Scholar]
  9. Ford J. M., Hait W. N. Pharmacology of drugs that alter multidrug resistance in cancer. Pharmacol Rev. 1990 Sep;42(3):155–199. [PubMed] [Google Scholar]
  10. Gottesman M. M., Pastan I. Biochemistry of multidrug resistance mediated by the multidrug transporter. Annu Rev Biochem. 1993;62:385–427. doi: 10.1146/annurev.bi.62.070193.002125. [DOI] [PubMed] [Google Scholar]
  11. Hidalgo I. J., Raub T. J., Borchardt R. T. Characterization of the human colon carcinoma cell line (Caco-2) as a model system for intestinal epithelial permeability. Gastroenterology. 1989 Mar;96(3):736–749. [PubMed] [Google Scholar]
  12. Hunter J., Jepson M. A., Tsuruo T., Simmons N. L., Hirst B. H. Functional expression of P-glycoprotein in apical membranes of human intestinal Caco-2 cells. Kinetics of vinblastine secretion and interaction with modulators. J Biol Chem. 1993 Jul 15;268(20):14991–14997. [PubMed] [Google Scholar]
  13. Inui K., Yamamoto M., Saito H. Transepithelial transport of oral cephalosporins by monolayers of intestinal epithelial cell line Caco-2: specific transport systems in apical and basolateral membranes. J Pharmacol Exp Ther. 1992 Apr;261(1):195–201. [PubMed] [Google Scholar]
  14. Ito S., Koren G., Harper P. A., Silverman M. Energy-dependent transport of digoxin across renal tubular cell monolayers (LLC-PK1). Can J Physiol Pharmacol. 1993 Jan;71(1):40–47. doi: 10.1139/y93-006. [DOI] [PubMed] [Google Scholar]
  15. Karlsson J., Kuo S. M., Ziemniak J., Artursson P. Transport of celiprolol across human intestinal epithelial (Caco-2) cells: mediation of secretion by multiple transporters including P-glycoprotein. Br J Pharmacol. 1993 Nov;110(3):1009–1016. doi: 10.1111/j.1476-5381.1993.tb13914.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Lamb J. F., Ogden P. Internalization of ouabain and replacement of sodium pumps in the plasma membranes of HeLa cells following block with cardiac glycosides. Q J Exp Physiol. 1982 Jan;67(1):105–119. doi: 10.1113/expphysiol.1982.sp002605. [DOI] [PubMed] [Google Scholar]
  17. Lamb J. F., Ogden P., Simmons N. L. Autoradiographic localisation of [3H]ouabain bound to cultured epithelial cell monolayers of MDCK cells. Biochim Biophys Acta. 1981 Jun 22;644(2):333–340. doi: 10.1016/0005-2736(81)90391-6. [DOI] [PubMed] [Google Scholar]
  18. Okamura N., Hirai M., Tanigawara Y., Tanaka K., Yasuhara M., Ueda K., Komano T., Hori R. Digoxin-cyclosporin A interaction: modulation of the multidrug transporter P-glycoprotein in the kidney. J Pharmacol Exp Ther. 1993 Sep;266(3):1614–1619. [PubMed] [Google Scholar]
  19. Oude Elferink R. P., Bakker C. T., Jansen P. L. Glutathione-conjugate transport by human colon adenocarcinoma cells (Caco-2 cells). Biochem J. 1993 Mar 15;290(Pt 3):759–764. doi: 10.1042/bj2900759. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Peters W. H., Roelofs H. M. Biochemical characterization of resistance to mitoxantrone and adriamycin in Caco-2 human colon adenocarcinoma cells: a possible role for glutathione S-transferases. Cancer Res. 1992 Apr 1;52(7):1886–1890. [PubMed] [Google Scholar]
  21. Schinkel A. H., Wagenaar E., van Deemter L., Mol C. A., Borst P. Absence of the mdr1a P-Glycoprotein in mice affects tissue distribution and pharmacokinetics of dexamethasone, digoxin, and cyclosporin A. J Clin Invest. 1995 Oct;96(4):1698–1705. doi: 10.1172/JCI118214. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Speeg K. V., Maldonado A. L., Liaci J., Muirhead D. Effect of cyclosporine on colchicine secretion by the kidney multidrug transporter studied in vivo. J Pharmacol Exp Ther. 1992 Apr;261(1):50–55. [PubMed] [Google Scholar]
  23. Tanigawara Y., Okamura N., Hirai M., Yasuhara M., Ueda K., Kioka N., Komano T., Hori R. Transport of digoxin by human P-glycoprotein expressed in a porcine kidney epithelial cell line (LLC-PK1). J Pharmacol Exp Ther. 1992 Nov;263(2):840–845. [PubMed] [Google Scholar]
  24. Thwaites D. T., Brown C. D., Hirst B. H., Simmons N. L. H(+)-coupled dipeptide (glycylsarcosine) transport across apical and basal borders of human intestinal Caco-2 cell monolayers display distinctive characteristics. Biochim Biophys Acta. 1993 Sep 19;1151(2):237–245. doi: 10.1016/0005-2736(93)90108-c. [DOI] [PubMed] [Google Scholar]
  25. Thwaites D. T., Brown C. D., Hirst B. H., Simmons N. L. Transepithelial glycylsarcosine transport in intestinal Caco-2 cells mediated by expression of H(+)-coupled carriers at both apical and basal membranes. J Biol Chem. 1993 Apr 15;268(11):7640–7642. [PubMed] [Google Scholar]

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