Table 5.

End superficial ascending Henle’s loop (macula densa) solute concentrations: baseline (A1) and hyperkalemia (A2)

Case A1	Lumen	Cell	Interstitium
PD, mV	15.5	−87.2
Concentrations, mM
Na+	73.5	13.0	186.5
K+	2.4	166.5	6.2
Cl−	64.6	16.5	160.7
${\text{HCO}}_3^{-}$	5.9	13.4	27.8
CO2	2.9	2.9	2.9
${\text{HPO}}_4^{2-}$	1.5	6.3	1.7
${\text{H}}_{\text{2}}{\text{PO}}_{\text{4}}^{-}$	3.7	6.8	0.9
Urea	9.7	6.7	6.3
${\text{NH}}_4^{+}$	1.2	3.6	1.0
Imp		125.3
pH	6.41	6.76	7.08

Case A2	Lumen	Cell	Interstitium
PD, mV	16.4	−81.1
Concentrations, mM
Na+	73.9	11.0	184.2
K+	3.2	171.6	7.8
Cl−	62.3	19.1	158.4
${\text{HCO}}_3^{-}$	8.9	19.5	29.3
CO2	2.9	2.9	2.9
${\text{HPO}}_4^{2-}$	1.9	7.8	1.8
${\text{H}}_{\text{2}}{\text{PO}}_{\text{4}}^{-}$	3.0	5.8	0.9
Urea	9.5	6.6	6.2
${\text{NH}}_4^{+}$	1.0	2.1	0.9
Imp		113.1
pH	6.59	6.93	7.10

Imp, cytosolic impermeant.