title: Effects of potassium channel openers on Na+ and K+ currents in rabbit sinus node and atrial myocytes.
abstract: The effects of the potassium channel openers (KCOs) Cromakalim and Lemakalim on rabbit sinoatrial and atrial myocytes were examined by means of the whole-cell patch-clamp technique. Lemakalin (up to 100 microM) had no effect on potassium current in sinoatrial cells. Both Lemakalim and Cromakalim (100 microM) displayed a two-fold action on atrial myocytes: (1) they increased an outwardly rectifying conductance at potentials positive to EK and, (2) they markedly decreased a TTX-sensitive Na+ current active in the voltage range -50/-30 mV. This novel action on TTX-sensitive currents is of particular interest since these two benzopyrans have been thought to specifically target potassium channels.
authors.affiliation: Department of Physiology and Biophysics, SUNY, Stony Brook 11794-8661, USA.
authors.forename: C
authors.initials: C
authors.lastname: Tromba
authors.forename: I S
authors.initials: IS
authors.lastname: Cohen
mesh_terms: D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology; D002478:Cells, Cultured; D019806:Cromakalim; D006325:Heart Atria / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects*; D011758:Pyrroles / Q000494:pharmacology; D011817:Rabbits; D012849:Sinoatrial Node / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D013779:Tetrodotoxin
chemical_list: D001578:Benzopyrans; D015221:Potassium Channels; D011758:Pyrroles; D019806:Cromakalim; D013779:Tetrodotoxin; D012964:Sodium; D011188:Potassium