Inactivation of Single Cardiac Na+ Channels in Three Different Gating Modes

Gating of Na channels. Inactivation modifiers discriminate among models

Macroscopic Na currents were recorded from N18 neuroblastoma cells by the whole-cell voltage-clamp technique. Inactivation of the Na currents was removed by intracellular application of proteolytic enzymes, trypsin, alpha-chymotrypsin, papain, or ficin, or bath application of N-bromoacetamide. Unlike what has been reported in squid giant axons and frog skeletal muscle fibers, these treatments o...

Identification of gating modes in single native Na+ channels from human atrium and ventricle.

The aim of the present study was to investigate the single-channel properties of different gating modes in the native human cardiac Na+ channel. Patch-clamp experiments were performed at low noise using ultrathick-walled pipettes. In 17 cell-attached patches containing only one channel, fast back and forth switching between five different Na+-channel gating modes (F-mode, M1-mode, M2-mode, S-mo...

Current-dependent gating of single cardiac sodium channels?

Based on studies of differences in physicochemical properties of antagonists and agonists of ionic channels it has been proposed that the magnitude of the elementary currents might influence the gating properties of ionic channel (personal communication) who reported that in inwardly rectifying potassium channels increased unitary currents induced prolonged single channel openings. A similar fi...

Inactivation Gating of Kv4 Potassium Channels

Kv4 channels represent the main class of brain A-type K+ channels that operate in the subthreshold range of membrane potentials (Serodio, P., E. Vega-Saenz de Miera, and B. Rudy. 1996. J. Neurophysiol. 75:2174- 2179), and their function depends critically on inactivation gating. A previous study suggested that the cytoplasmic NH2- and COOH-terminal domains of Kv4.1 channels act in concert to de...

Inactivation gating of potassium channels Dissertation