Abstract
1. Na+ current kinetics were studied in isolated atrial myocytes from the adult cat using the single suction-pipette voltage-clamp technique. 2. Current-voltage and conductance-voltage relationships were similar to those described in other cardiac myocyte preparations. 3. Analysis of Na+ current decay using single-pulse, double-pulse and tail current measurements were in agreement and demonstrate a second-order process of current decay. 4. Voltage dependence of steady-state inactivation curves was not symmetrical, having an inflexion at about -90 mV. These results suggest more than a single inactivation process for Na+ channel in the negative potential region. 5. Recovery of Na+ current from inactivation had a sigmoid time course: an initial slow component (delay) followed by a fast and then a second slow component. Increasing the pre-pulse duration slowed the time course of recovery. 6. Taken together, the results were consistent with the presence of multiple inactivated states for the atrial myocyte Na+ channel.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
