ALDO	Aldosterone
ENaC	Epithelial Na+ channel
ISC	Short-circuit current
Po	Open probability
PI3K	Phosphatidylinositide 3’-kinase
PI(4)P5K	Phosphatidylinositol-4-phosphate 5-kinase
SGK1	Serum- and glucocorticoid-induced kinase 1
$k_I$	The insertion rate of ENaC into the apical membrane for the intracellular store site
$k_E$	The endocytotic rate of ENaC from the apical membrane to the intracellular recycling site
$k_R$	The recycling rate of ENaC from the recycling state to the insertion state
$k_D$	The degradation rate of ENaC from the recycling state to the degradation state
$N_R$	Relocation number of ENaC to the apical membrane state
$R_R$	The recycling rate of ENaC from the recycling state to the insertion state
$I_{Total}$	The cumulative Na+ absorption (ISC)
$T_{ENaC}$	The total amount of ENaC
$T_{AM}$	The residency time of ENaC in the apical membrane how long an individual ENaC stays in the apical membrane each time after the insertion of ENaC into the apical membrane
$T_{CTAM}$	The cumulative time how long an individual ENaC stays in the apical membrane during its whole life-time period before degradation
$T_{WLT}$	The whole life-time after the first insertion to the apical membrane
Insert	Insert state
Apical	Apical state
Recycl	Recycle state
Degrad	Degradation state
$Insert\left(t\right)$	The amount of ENaC in the insertion state at time = $t$ after insulin application
$Apical\left(t\right)$	The amount of ENaC in the apical membrane state at time = $t$ after insulin application
$Recycl\left(t\right)$	The amount of ENaC in the recycling state at time = $t$ after insulin application
$Degrad\left(t\right)$	The amount of ENaC in the degradation state at time = $t$ after insulin application
$Inser{t}_0$	$Insert\left(0\right)$
$Apica{l}_0$	$Apical\left(0\right)$
$Recyc{l}_0$	$Recycl\left(0\right)$
$Derga{d}_0$	$Degrad\left(0\right)$