“…In such media, red cells permeabilized to divalent cations with the ionophore A23187, and indirectly to K+ by increased [Ca2+]i, maintain their normal volume, pH, rnembrane potential and ionic composition, except for the intended divalent cation concentrationi changes (Ferreira & Lew, 1976: Lew & Brown, 1979Lew & GarciaSancho, 1989). …”