Automated Patch Clamp Screening of Amiloride and 5- N, N-Hexamethyleneamiloride Analogs Identifies 6-Iodoamiloride as a Potent Acid-Sensing Ion Channel Inhibitor

Rocio K. Finol-Urdaneta, Jeffrey R. McArthur, Ashraf Aboelela, Richard S. Bujaroski, Hiwa Majed, Alejandra Rangel, David J. Adams, Marie Ranson, Michael J. Kelso, Benjamin J. Buckley

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1 Citation (Scopus)


Acid-sensing ion channels (ASICs) are transmembrane sensors of extracellular acidosis and potential drug targets in several disease indications, including neuropathic pain and cancer metastasis. The K+-sparing diuretic amiloride is a moderate nonspecific inhibitor of ASICs and has been widely used as a probe for elucidating ASIC function. In this work, we screened a library of 6-substituted and 5,6-disubstituted amiloride analogs using a custom-developed automated patch clamp protocol and identified 6-iodoamiloride as a potent ASIC1 inhibitor. Follow-up IC50 determinations in tsA-201 cells confirmed higher ASIC1 inhibitory potency for 6-iodoamiloride 94 (hASIC1 94 IC50 = 88 nM, cf. amiloride 11 IC50 = 1.7 μM). A similar improvement in activity was observed in ASIC3-mediated currents from rat dorsal root ganglion neurons (rDRG single-concentration 94 IC50 = 230 nM, cf. 11 IC50 = 2.7 μM). 6-Iodoamiloride represents the amiloride analog of choice for studying the effects of ASIC inhibition on cell physiology.

Original languageEnglish
Pages (from-to)3367–3379
Number of pages13
JournalMolecular Pharmaceutics
Issue number7
Publication statusPublished - 1 Jun 2023


  • 6-iodoamiloride
  • acid-sensing ion channel
  • amiloride
  • ASIC
  • ASIC inhibition
  • small molecule
  • synchropatch

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