Characterization of voltage-gated sodium-channel blockers by electrical stimulation and fluorescence detection of membrane potential

• Published in: Nature biotechnology 2006-04, Vol.24 (4), p.439-446
• Main Authors: González, Jesús E, Huang, Chien-Jung, Harootunian, Alec, Maher, Michael P, Quan, Catherine, Raj, Christopher D, McCormack, Ken, Numann, Randal, Negulescu, Paul A
• Format: Article
• Language: English
• Subjects: Agriculture; Analysis; Antidepressants; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Biomedicine; Biotechnology; Cells, Cultured; Drug Design; Electric fields; Electric Stimulation - methods; General pharmacology; Humans; Ion Channel Gating - drug effects; Ion Channel Gating - physiology; Ions; Kidneys; Life Sciences; Measurement techniques; Medical sciences; Membrane Potentials - drug effects; Membrane Potentials - physiology; Microscopy, Fluorescence - methods; Neurons - drug effects; Neurons - physiology; Patch-Clamp Techniques - methods; Pharmaceutical Preparations - administration & dosage; Pharmacology. Drug treatments; Physiology; Probes; Research methodology; Sodium; Sodium Channels - drug effects; Sodium Channels - physiology
• ISSN: 1087-0156; 1546-1696
• DOI: 10.1038/nbt1194

Voltage-gated ion channels regulate many physiological functions and are targets for a number of drugs. Patch-clamp electrophysiology is the standard method for measuring channel activity because it fulfils the requirements for voltage control, repetitive stimulation and high temporal resolution, but it is laborious and costly. Here we report an electro-optical technology and automated instrument, called the electrical stimulation voltage ion probe reader (E-VIPR), that measures the activity of voltage-gated ion channels using extracellular electrical field stimulation and voltage-sensitive fluorescent probes. We demonstrate that E-VIPR can sensitively detect drug potency and mechanism of block on the neuronal human type III voltage-gated sodium channel expressed in human embryonic kidney cells. Results are compared with voltage-clamp and show that E-VIPR provides sensitive and information-rich compound blocking activity. Furthermore, we screened ∼400 drugs and observed sodium channel–blocking activity for ∼25% of them, including the antidepressants sertraline (Zoloft) and paroxetine (Paxil).