title: Dibenzylamine--a novel blocker of the voltage-dependent K+ current in myocardial mouse cells.
abstract: Ventricular myocytes of the mouse ventricle were voltage clamped with a patch-clamp technique in the whole-cell configuration. At depolarizing voltage pulses, these myocytes develop a large voltage-dependent K+ outward current. Application of the drug dibenzylamine (DBA) to the bath solution blocked the voltage-dependent K+ current. The concentration/response relationship for the peak current at +40 mV indicates a 1:1 binding of the drug to the receptor with a concentration of half maximum effect of 43.1 micromol/l. The block did not require activation of the channels by depolarizing pulses. At concentrations causing partial block (25 micromol/l), the block was independent of voltage. At the same concentration, DBA completely blocked the slow component of the recovery from inactivation (-80 mV) whereas steady-state inactivation was not altered. It is concluded that DBA is a novel blocker of the voltage-dependent K+ current in mouse cardiac myocytes which preferentially affects the current component generating the slow recovery from inactivation.
authors.affiliation: Institut für Physiologie der Friedrich-Schiller-Universität Jena, Abteilung Herz-Kreislauf-Physiologie, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Doepner
authors.forename: R
authors.initials: R
authors.lastname: Koopmann
authors.forename: A
authors.initials: A
authors.lastname: Knopp
authors.forename: H
authors.initials: H
authors.lastname: Hirche
authors.forename: K
authors.initials: K
authors.lastname: Benndorf
mesh_terms: D000818:Animals; D001596:Benzylamines / Q000494:pharmacology*; D002478:Cells, Cultured; D006321:Heart / Q000187:drug effects*; D006352:Heart Ventricles; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009206:Myocardium / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D015221:Potassium Channels / Q000378:metabolism*
chemical_list: D001596:Benzylamines; D026902:Potassium Channel Blockers; D015221:Potassium Channels; C005051:dibenzylamine; D011188:Potassium