Table 4.

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 ($T_{AM}=1/k_E$) and the cumulative time how long an individual ENaC stays in the apical membrane during its whole life-time period before degradation ($T_{CTAM}=\left(1+K_R/k_D\right)/k_E)$, and whole life-time after the first insertion to the apical membrane ($T_{WLT}=1/k_E+N_R\left(1/k_R+1/k_I+1/k_E\right)+1/k_D$) in the presence and absence of 100 nM insulin with and without 1 µM aldosterone treatment for 20 h.

Insulin	ALDO	${\mathit{T}}_{\mathit{A}\mathit{M}}$ (h)	${\mathit{T}}_{\mathit{C}\mathit{T}\mathit{A}\mathit{M}}$ (h)	${\mathit{T}}_{\mathit{W}\mathit{L}\mathit{T}}$ (h)
(+)	(+)	0.49 ± 0.05 NS	1.44 ± 0.08 #	3.35 ± 0.16 NS
	(−)	0.53 ± 0.04	0.88 ± 0.11	2.80 ± 0.32
(−)	(+)	0.45 ± 0.08 *	0.75 ± 0.11 *	4.18 ± 0.41 **
	(−)	0.19 ± 0.02	0.28 ± 0.02	2.82 ± 0.15

ALDO, aldosterone. ^# significantly different between aldosterone (+) and (−) in Insulin (+) at p < 0.005. (n = 5) * significantly different between aldosterone (+) and (−) in Insulin (-) at p < 0.005 (n = 4). ** significantly different between aldosterone (+) and (−) in Insulin (-) at p < 0.025 (n = 4). ^NS no significant difference between aldosterone (+) and (−) in Insulin (+) (n = 5). Results shown in Table 3 are expressed as the mean ± standard error (S.E.).