KCl cotransport in HbAA and HbSS red cells: activation by intracellular acidity and disappearance during maturation.

Low intracellular pH was shown to be a potent activator of the KCl cotransport system in HbSS red cells, and in reticulocyte-rich fractions of HbAA red cells. Rheological experiments indicated that cell dehydration via the KCl cotransporter in response to low pH decreased the filterability of HbSS red cells. In vitro maturation experiments showed that the KCl cotransport system was rendered cryptic rapidly, in contrast to choline transport, and serine transport via system ASC, which disappeared much more slowly.