Table 1

 Main pathways involved in the regulation of intracellular sodium concentration ([Na+]i) in cardiomyocytes

PathwayStoichiometryAbbreviation
Modified from Bers et al.5
Sodium influx pathways
    Sodium channel current (peak and late, through the voltage-gated sodium channel)INa
    Sodium-hydrogen exchanger1 Na+:1 H+NHE
    Sodium-calcium exchanger (in forward mode)3 Na+:1 Ca2+NCX
    Sodium-bicarbonate co-transporter1 Na+:1 HCO3NBC
    Sodium-potassium-chloride co-transporter1 Na+:1 K+:2 ClNKCC
    Sodium-magnesium antiporter2 Na+:1 Mg2+NaMgX
Sodium efflux pathways
    Sodium-potassium ATPase3 Na+:2 K+Sodium pump
    Sodium-calcium exchanger (in reverse mode)3 Na+:1 Ca2+NCX