Energy reserve and cation composition of irreversibly sickled cells in vivo.

Cation composition, cellular hydration, and adenosinetriphosphate (ATP) content were measured in irreversible sickle cells (ISC's) separated from the blood of patients with sickle cell anaemia. Total monovalent cation (Na+ + K+) content was markedly reduced in ISC's and this largely was due to cell K+ depletion. Corresponding to the reduced cation content, cells were dehydrated as indicated by a reduced mean cell volume. ISC's also appeared to be grossly depleted of ATP. These biochemical characteristics allow us to expand the definition of ISC's beyond morphologic characteristics. In addition, these chemical alterations provide a means for elucidating the mechanism of ISC production in vitro.