Determination of the Upper Bound of Intracellular [Na+] by Electrophysiological Method: Probing the Subsarcolemmal [Na+] (original) (raw)

This study investigates the upper bound of intracellular sodium concentration ([Na+]) in cardiac cells using electrophysiological methods, focusing on subsarcolemmal [Na+]. The research reveals that ambient conditions, such as temperature and pacing frequency, significantly influence action potential duration (APD) and sodium concentration. Through various experiments, the authors demonstrate a stable subsarcolemmal [Na+] of approximately 11 mM across different pipette concentrations and highlight its regulatory mechanisms in the context of heart conditions.