title: Photocontrol of Voltage-Gated Ion Channel Activity by Azobenzene Trimethylammonium Bromide in Neonatal Rat Cardiomyocytes.
abstract: The ability of azobenzene trimethylammonium bromide (azoTAB) to sensitize cardiac tissue excitability to light was recently reported. The dark, thermally relaxed trans- isomer of azoTAB suppressed spontaneous activity and excitation propagation speed, whereas the cis- isomer had no detectable effect on the electrical properties of cardiomyocyte monolayers. As the membrane potential of cardiac cells is mainly controlled by activity of voltage-gated ion channels, this study examined whether the sensitization effect of azoTAB was exerted primarily via the modulation of voltage-gated ion channel activity. The effects of trans- and cis- isomers of azoTAB on voltage-dependent sodium (INav), calcium (ICav), and potassium (IKv) currents in isolated neonatal rat cardiomyocytes were investigated using the whole-cell patch-clamp technique. The experiments showed that azoTAB modulated ion currents, causing suppression of sodium (Na+) and calcium (Ca2+) currents and potentiation of net potassium (K+) currents. This finding confirms that azoTAB-effect on cardiac tissue excitability do indeed result from modulation of voltage-gated ion channels responsible for action potential.
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Russian Federation.
authors.forename: Sheyda R
authors.initials: SR
authors.lastname: Frolova
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Russian Federation.
authors.forename: Olga
authors.initials: O
authors.lastname: Gaiko
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Russian Federation.
authors.forename: Valeriya A
authors.initials: VA
authors.lastname: Tsvelaya
authors.affiliation: Institute of Theoretical and Experimental Biophysics, Russian Academy of Science, Pushchino, Russian Federation.
authors.forename: Oleg Y
authors.initials: OY
authors.lastname: Pimenov
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Russian Federation.
authors.forename: Konstantin I
authors.initials: KI
authors.lastname: Agladze
mesh_terms: D000200:Action Potentials; D000818:Animals; D000831:Animals, Newborn; D001391:Azo Compounds / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry; D005353:Fibronectins / Q000737:chemistry; D006352:Heart Ventricles / Q000473:pathology; D007477:Ions; D008027:Light; D008564:Membrane Potentials; D008744:Methylamines / Q000737:chemistry*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000737:chemistry; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D001965:Bromides; D005353:Fibronectins; D007477:Ions; D008744:Methylamines; D024642:Potassium Channels, Voltage-Gated; D012964:Sodium; C027451:methylamine; C009850:azobenzene; D011188:Potassium; D002118:Calcium