Recording hERG Potassium Currents and Assessing the Effects of Compounds Using the Whole-Cell Patch-Clamp Technique

  • Ray M. Helliwell
Part of the Methods in Molecular Biology book series (MIMB, volume 491)


The complex gating of the hERG channel makes it ideally suited to its principal role in controlling phase 3 repolarization of the cardiac ventricular action potential. Any abnormal delay in repolarization can lead to the re-activation of Ca2+ channels, giving rise to early after-depolarizations, and coupled with increased cardiac dispersion, typically associated with these delays, provides respectively both the trigger and substrate for the potentially life threatening arrhythmia Torsardes de Pointes (TdP). Owing to the fundamental role of hERG in controlling the duration of the cardiac action potential, it is not surprising that any drugs that potently and selectively block this channel are liable to have these effects. Consequently, much effort has been expended in developing standard voltage protocols to reliably assess the effects of compounds on hERG currents in vitro. This chapter describes how to record hERG currents in a recom-binant cell line using the whole-cell patch-clamp technique. It also provides typical voltage protocols used for assessing the basic electrophysiological properties of these currents and for assessing the effects of compounds on hERG tail currents.

Key words:

hERG; Patch-clamp Ion channels Safety pharmacology long QT. 



I would like to thank the Millipore Ion Channel Group (Cambridge, UK) particularly Helen Swain and Louise Webdale for help with the tissue culture and cell preparation sections.


  1. 1.
    Haverkamp, W., Breithardt, G., Camm, A.J., Janse, M.J., Rosen, M.R., Ant-zelevitch, C., Escande, D., Franz, M., Malik, M., Moss, A., and Shah, R. (2000) The potential for QT prolongation and pro-arrhythmia by non-anti-arrhythmic drugs:clinical and regulatory implications. Report on a Policy Conference of the European Society of Cardiology. Cardiovasc. Res. 47,219–233.CrossRefPubMedGoogle Scholar
  2. 2.
    Gupta, A., Lawrence, A.T., Krishnan, K., Kavinsky, C.J., and Trohman, R.G. (2007)Current concepts in the mechanisms and management of drug-induced QT prolongation and torsade de pointes. Am. Heart J. 153, 891–899.CrossRefPubMedGoogle Scholar
  3. 3.
    Fermini, B. and Fossa, A.A. (2003) The impact of drug-induced QT interval prolongation on drug discovery and development. Nat. Rev. Drug Discov. 2, 439–447.CrossRefPubMedGoogle Scholar
  4. 4.
    Shah, R.R. (2002) The significance of QT interval in drug development. Br. J. Clin.Pharmacol. 54, 188–202.CrossRefPubMedGoogle Scholar
  5. 5.
    Dorn, A., Hermann, F., Ebneth, A., Both-mann, H., Trube, G., Christensen, K., and Apfel, C. (2005) Evaluation of a high-throughput fluorescence assay method for HERG potassium channel inhibition.J. Biomol. Screen. 10, 339–347.CrossRefPubMedGoogle Scholar
  6. 6.
    Guthrie, H., Livingston, F.S., Gubler, U., and Garippa, R. (2005) A place for high-throughput electrophysiology in cardiac safety: screening hERG cell lines and novel compounds with the ion works HTTM system. J. Biomol. Screen. 10, 832–840.CrossRefPubMedGoogle Scholar
  7. 7.
    Diaz, G.J., Daniell, K., Leitza, S.T., Martin, R.L., Su, Z., McDermott, J.S., Cox, B.F., and Gintant, G.A. (2004) The [3H]dofe-tilide binding assay is a predictive screening tool for hERG blockade and proarrhythmia:comparison of intact cell and membranepreparations and effects of altering [K+]o.J. Pharmacol. Toxicol. Methods 50, 187–199.CrossRefPubMedGoogle Scholar
  8. 8.
    Tang, W., Kang, J., Wu, X., Rampe, D., Wang, L., Shen, H., Li, Z., Dunnington, D., and Garyantes, T. (2001) Development and evaluation of high throughput functional assay methods for HERG potassium channel. J. Biomol. Screen. 6, 325–331.CrossRefPubMedGoogle Scholar
  9. 9.
    Kamiya, K., Niwa, R., Mitcheson, J.S., and Sanguinetti, M.C. (2006) Molecular determinants of HERG channel block. Mol.Pharmacol. 69, 1709–1716.CrossRefPubMedGoogle Scholar
  10. 10.
    Rodriguez-Menchaca, A., Ferrer-Villada, T., Lara, J., Fernandez, D., Navarro-Polanco, R.A. and Sanchez-Chapula, J.A. (2006) Block of HERG channels by berberine:mechanisms of voltage- and state-dependence probed with site-directed mutant channels. J. Cardiovasc. Pharmacol. 47, 21–29.CrossRefPubMedGoogle Scholar
  11. 11.
    Bottino, D., Penland, R.C., Stamps, A., Traebert, M., Dumotier, B., Georgiva, A., Helmlinger, G., and Lett, G.S. (2006) Pre-clinical cardiac safety assessment of pharmaceutical compounds using an integrated systems-based computer model of the heart.Prog. Biophys. Mol. Biol. 90, 414–443.CrossRefPubMedGoogle Scholar
  12. 12.
    Crumb, W.J., Jr., Ekins, S., Sarazan, R.D., Wikel, J.H., Wrighton, S.A., Carlson, C., and Beasley, C.M., Jr. (2006) Effects of antipsychotic drugs on I(to), I (Na), I (sus), I (K1), and hERG: QT prolongation, structure activity relationship, and network analysis. Pharmacol. Res. 23, 1133–1143.CrossRefGoogle Scholar
  13. 13.
    Jamieson, C., Moir, E.M., Rankovic, Z., and Wishart, G. (2006) Medicinal chemistry of hERG optimizations: highlights and hang-ups. J. Med. Chem. 49, 5029–5046.CrossRefPubMedGoogle Scholar
  14. 14.
    Wible, B.A., Hawryluk, P., Ficker, E., Kury-shev, Y.A., Kirsch, G., and Brown, A.M.(2005) HERG-Lite: a novel comprehensive high-throughput screen for drug-inducedhERG risk. J. Pharmacol. Toxicol. Methods 52, 136–145.CrossRefPubMedGoogle Scholar
  15. 15.
    van der Heyden, M.A., Smits, M.E., and Vos, M.A. (2007) Drugs and trafficking of ion channels: a new pro-arrhythmic threat on the horizon? Br. J. Pharmacol. 153, 406–409.CrossRefPubMedGoogle Scholar
  16. 16.
    Hancox, J.C. and Curtis, M.J. (2006) Methods for screening drugs for their pro-arrhythmic liability: does the rabbit ventricular wedge hold the key? J. Pharmacol.Toxicol. Methods 54, 257–260.CrossRefPubMedGoogle Scholar
  17. 17.
    Lawrence, C.L., Pollard, C.E., Hammond, T.G., and Valentin, J.P. (2005) Nonclinical proarrhythmia models: predicting Torsades de Pointes. J. Pharmacol. Toxicol. Methods 52, 46–59.CrossRefPubMedGoogle Scholar
  18. 18.
    Shah, R.R. and Hondeghem, L.M. (2005)Refining detection of drug-induced proar-rhythmia: QT interval and TRIaD. Heart Rhythm 2, 758–772.CrossRefPubMedGoogle Scholar
  19. 19.
    Valentin, J.P., Hoffmann, P., De Clerck, F., Hammond, T.G., and Hondeghem, L.(2004) Review of the predictive value of the Langendorff heart model (Screenit system) in assessing the proarrhythmic potential of drugs. J. Pharmacol. Toxicol. Methods 49, 171–181.CrossRefPubMedGoogle Scholar
  20. 20.
    Witchel, H.J., Milnes, J.T., Mitcheson, J.S., and Hancox, J.C. (2002) Troubleshooting problems with in vitro screening of drugs for QT interval prolongation using HERG K+ channels expressed in mammalian cell lines and Xenopus oocytes. J. Pharmacol.Toxicol. Methods 48, 65–80.CrossRefPubMedGoogle Scholar
  21. 21.
    Rudy, B. and Iversen, L.E. (eds.) (1992) Ion channels methods in enzymology 207. Academic, London.Google Scholar
  22. 22.
    Molleman, A. (2003) Patch clamping: an introductory guide to patch clamp electro-physiology. Wiley, Chichester.Google Scholar
  23. 23.
    Sakmann, B. and Neher E. (eds.) (1995) Single-channel recording. Plenum, New York.Google Scholar
  24. 24.
    Yao, J.A., Du, X., Lu, D., Baker, R.L., Daharsh, E., and Atterson, P. (2005) Estimation of potency of HERG channel blockers: impact of voltage protocol and temperature. J. Pharmacol. Toxicol. Methods 52, 146–153.CrossRefPubMedGoogle Scholar
  25. 25.
    Rampe, D., Roy, M.L., Dennis, A., and Brown, A.M. (1997) A mechanism for the proarrhythmic effects of cisapride (Propul-sid): high affinity blockade of the human cardiac potassium channel HERG. FEBS Lett. 417, 28–32.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Ray M. Helliwell

There are no affiliations available

Personalised recommendations