Biopolymers and cell. 1999; 15 (1): 43 - 48

Influence of divalent cations Ca2+ and Zn2+ on the activation of posthypertonic hemolysis of human erythrocytes

S. V. Patelaros

Human erythrocytes (RBC) were incubated for various time at 37 °C in hypertonic solutio,ts of NaCl (1.5 M) or sucrose (1.2 M) and then rehydrated in isotonic NaCl or sucrose media in the presence or absence of divalent cations Ca + and Zn +. After equilibration in hypertonic sucrose both cations significantly increased the extent of hemolysis at concentration dependent manner, but show more complex response after equilibration in hypertonic NaCl media. In thin case both Ca and Zn2* ions lose their activation ability during rehydration in isotonic NaCl media, and Caz+ did so in isotonic sucrose. Dehydration of cells in hypertonic sucrose solutions in the presence of 100 mt/1 of cations Na+, .ff+ and Mg leads to decrease the extent of lysis after rehydration but dues not influence activation ability of C«2+ and Zn+, whereas addition of Ca to hypertonic sucrose solution completely abolishes activation effect of both ions. The model of posthypertonic lysis is presented according to which action of cations Ca2+ and Zn2* may be explained by their specific binding to activatory and inhibitory membrane sites, regulating membrane permeability during reswelling from hypertonic salines.