Studies of Erythrocyte Membrane Loss Produced by Amphipathic Drugs and in Vitro Storage

Abstract
Four amphipathic drugs, primaquine, propranolol, chlorpromazine and tetracaine, were used to cause endocytosis in glucose-depleted red cells, and the relative reduction of membrane surfaces was measured by the toluidine blue (TB) method. The TB measurements correlated well with the observed EM alterations. In vitro blood storage studies indicated loss of cell membrane during storage and correlated with decreasing uptake of TB by the red cells. Regeneration of cellular ATP with adenosine did not always restore TB uptake by the cells. Loss of red blood cell membrane either by exocytosis or endocytosis may occur during normal in vivo aging, and may be increased in pathological states or by the action of drugs.