The pH dependency of sodium and chloride transport in the isolated human cornea.

Sodium and chloride net transport in isolated human cornea preparations were found to be pH dependent. Sodium net transport was directed from aqueous humor to tear side at pH 7.6 and 8.6. At pH 7.4, net sodium flux did not differ significantly from zero, and at pH 7.0, net sodium transport was directed toward the aqueous humor side. Chloride net flux at pH 8.6 and 7.6 was also directed from aqueous humor to tear side. Acidification of the bathing solution to pH 7.4 and 7.0 was followed by a decrease in chloride net fluxes to values not significantly different from zero.