Table 1.

Solutions used in pH_i studies

	Solutions
	A (high Cl−, 0 Na+)	B (0 Cl−, 0 Na+)	C (0 Cl−, high Na+)	D (0 Cl−, 0 Na+, 20 mM ${\mathrm{NH}}_4^{+}$)	E (high Cl−, 0 Na+, 25 mM ${\mathrm{HCO}}_3^{-}$)	F (0 Cl−, 0 Na+, 25 mM ${\mathrm{HCO}}_3^{-}$)	G (0 Cl−, high Na+, 25 mM ${\mathrm{HCO}}_3^{-}$)
TMA-Cl−	140				115
TMA-OH		140		120		115
$\mathrm{TMA}-{\mathrm{HCO}}_3^{-}$					25	25
NH4OH				20
Na+ Gluconate			140				115
NaHCO3							25
Gluconic acid lactone		140		140		115
K2HPO4	2.5	2.5	2.5	2.5	2.5	2.5	2.5
MgCl2	1				1
Mg Gluconate		1	1	1		1	1
CaCl2	1				1
Ca Gluconate		12.5	12.5	12.5		10	10
Glucose	5	5	5	5	5	5	5
l-Alanine	5	5	5	5	5	5	5
HEPES	5	5	5	5

All values are expressed in mM. All solutions were adjusted to an osmolality of 295 mosmol/kgH₂O. ${\mathrm{HCO}}_3^{-}$-containing solutions were bubbled with 95% O₂–5% CO₂ and had pH of 7.4. Non-${\mathrm{HCO}}_3^{-}$-containing solutions were bubbled with 100% O₂ and had pH of 7.4. pH_i, Intracellular pH; TMA, tetramethylammonium.