A quite simple method for obtaining young and old erythrocytes is presented. Mean corpuscular volume, glutamic oxaloacetic transaminase activity which is one of the best age parameters, and contents of total sialic acids in erythrocyte membranes were determined in whole erythrocyte population and in low (old) and high (young) density fractions separated by centrifugation of packed cells obtained from 23 healthy subjects. Glutamic oxaloacetic transaminase (GOT) activity, and contents of total sialic acids in erythrocyte membranes were significantly higher in young cells then in old ones, or in the whole population of erythrocytes. The presented results suggest that this method is simple for obtaining two different fractions of erythrocytes and that erythrocytes lose intact sialic acids together with their membrane during erythrocytes senescence.

Keywords: total sialic acids (TSA), glutamic oxaloacetic transaminase (GOT), mean corpuscular volume (MCV), age of erythrocytes