[Lipid composition and structure-functional properties of membranes of erythrocytes of different ages]

Age-dependent alterations of plasmatic membranes were studied in rabbit erythrocytes after separation of erythrocytes of various age by means of centrifugation. The membrane structure characteristics were studied using a fluorescent probe pyrene and spin-labelled probes--nitroxyl derivatives of stearic acid and carboline derivatives. Microviscosity of the membrane lipid phase was shown to increase depending on the cell age. Alterations in the membrane structure were accompanied by a decrease in activity of Na-, K+-ATPase. The content and ratio of membrane lipids were altered with an increase in the cell age, which could be one of reasons of the membrane microviscosity elevation. The age-dependent alterations in erythrocyte membranes may be related, firstly, to the mechanism of old erythrocyte elimination from circulation and, secondly, to be the common characteristic for cell ageing, according to the "membrane hypothesis" of ageing.