18
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Block of sodium current by heptanol in voltage-clamped canine cardiac Purkinje cells.

      1 ,
      Circulation research

      Read this article at

      ScienceOpenPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Heptanol blocks sodium current (INa) in nerve, but its effects on cardiac INa have not been well characterized. Block of INa by heptanol was studied in 16 internally perfused voltage-clamped cardiac Purkinje cells at reduced Na+ (45 mM outside, 0 mM inside). Heptanol block of peak sodium conductance was well described by a single-site binding curve with half block at 1.3 mM (20 degrees C) and showed no "use dependence." With 1.5 mM heptanol, block increased slightly by 0.7%/degrees C from 10 degrees C to 27 degrees C. With 3.0 mM heptanol, steady-state availability shifted by 9.4 +/- 1.3 mV (n = 6) in the hyperpolarizing direction, and steady-state activation shifted by 8.3 +/- 2.2 mV (n = 5) in the depolarizing direction, thus closing off the INa "window current." Heptanol also decreased the time to peak and accelerated the decay of INa. Similar results were found with octanol at lower concentrations. These alcohols have important effects on cardiac INa at concentrations used in studies for cellular uncoupling in heart.

          Related collections

          Author and article information

          Journal
          Circ. Res.
          Circulation research
          0009-7330
          0009-7330
          Apr 1991
          : 68
          : 4
          Affiliations
          [1 ] Cardiac Electrophysiology Laboratories, University of Chicago, Ill.
          Article
          1849060
          50954fbe-537b-46cb-b85a-1a8daaef19e1
          History

          Comments

          Comment on this article