Table 7.

End connecting tubule solute concentrations and principal cell luminal fluxes: combined aldosterone plus reduced NaCl cotransporter (B2) and with reduced ammoniagenesis (B3)

Case B2	Lumen	Cell	Interstitium
PD, mV	−46.8	−72.4
Concentrations, mM
Na+	64.3	12.6	143.0
K+	33.2	150.3	5.5
Cl−	91.5	18.8	117.4
${\text{HCO}}_3^{-}$	7.0	28.8	27.1
CO2	1.8	1.8	1.8
${\text{HPO}}_4^{2-}$	0.5	22.7	1.9
${\text{H}}_{\text{2}}{\text{PO}}_{\text{4}}^{-}$	7.4	8.2	0.6
Urea	21.0	6.7	4.7
${\text{NH}}_4^{+}$	9.4	0.5	0.4
Imp		16.5
pH	5.67	7.24	7.29
PC fluxes, nmol/s/cm2
ENaC	7.93
ROMK	−1.63

Case B3	Lumen	Cell	Interstitium
PD, mV	−48.9	−72.4
Concentrations, mM
Na+	66.4	14.3	143.3
K+	34.3	148.3	5.4
Cl−	92.3	19.4	117.5
${\text{HCO}}_3^{-}$	5.8	33.6	27.0
CO2	1.9	1.9	1.8
${\text{HPO}}_4^{2-}$	0.4	21.2	1.9
${\text{H}}_{\text{2}}{\text{PO}}_{\text{4}}^{-}$	7.0	6.8	0.6
Urea	19.8	6.6	4.6
${\text{NH}}_4^{+}$	5.1	0.2	0.2
Imp		13.5
pH	5.56	7.29	7.27
PC fluxes, nmol/s/cm2
ENaC	8.89
ROMK	−2.15

ENaC, epithelial Na⁺ channel; ROMK, renal outer medullary K⁺ channel; Imp, cytosolic impermeant.