[Sorption of phthalocyanine dye by erythrocyte membranes in buffered solutions of different tonicities].

The sorption of nonpenetrating vital phthalocyanine dye--Heliogen Blue (HB) into the cells was studied on the human red cells incubated in hypertonic, isotonic and hypotonic solutions. The alteration in the outer membrane surface was detected using the monomer-dimer ratio (M/D) deduced from the absorbtion spectra of the sorbed dye, and the concentration (C) of the dye in membrane. The decrease in M/D and C was found in hypotonic and hypertonic conditions, resp. The increase in the number of binding sites caused by conformational changes in membrane is discussed.