title: Angiotensin II modulates cardiac Na+ channels in neonatal rat.
abstract: Since chronic congestive heart failure syndromes are associated with both elevated circulating levels of angiotensin II and potentially lethal ventricular tachyarrhythmias, we investigated the effect of angiotensin II on voltage-dependent cardiac Na+ currents. Single-channel Na+ currents in neonatal rat ventricular myocytes were studied using the patch clamp method in the cell-attached mode. Angiotensin II applied outside the patch increased the frequency of opening and rates of activation and inactivation of single-channel Na+ currents within the patch. These effects were mimicked by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) and were prevented by prior incubation with TPA. Therefore, we propose that angiotensin II modulates cardiac Na+ currents by a cytoplasmic second messenger, perhaps protein kinase C, and this may predispose toward arrhythmia.
authors.affiliation: Department of Medicine, University of Texas Medical Branch, Galveston 77550.
authors.forename: J R
authors.initials: JR
authors.lastname: Moorman
authors.forename: G E
authors.initials: GE
authors.lastname: Kirsch
authors.forename: A E
authors.initials: AE
authors.lastname: Lacerda
authors.forename: A M
authors.initials: AM
authors.lastname: Brown
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D004553:Electric Conductivity; D006321:Heart / Q000502:physiology*; D066298:In Vitro Techniques; D008564:Membrane Potentials; D009206:Myocardium / Q000166:cytology; D011493:Protein Kinase C / Q000502:physiology; D051381:Rats; D015398:Signal Transduction; D015222:Sodium Channels / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D015222:Sodium Channels; D000804:Angiotensin II; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate