Analysis of glycoconjugate contents of rat erythrocytes concerning different ageing periods

Aging, is a time-dependent process that contain cell damage caused by molecular damages and eventually functional impairment of tissues and organs. The molecular mechanism of aging is not yet been resolved so far. In addition, the possible roles of cell surface carbohydrates, which are very important in recognition phenomena, on aging process are not yet clear. In this study, alterations of glycoconjugates of membrane glycoproteins from erythrocytes, which are selected as a model, during ageing, were evaluated with lectin histochemistry and lectin blotting studies in 1, 4 and 7 month old rats. On the other hand, carbohydrate compositions of spleen preparations of rats belonging the analyzed ages were evaluated. Lectin histochemistry results indicated that ?(2 ? 3) ve ?(2 ? 6)-linked sialic acids are intensively found in erythrocyte membranes, but this intensities of sialic acids are decreased with age. Similar results were obtained from lectin blotting studies with same lectins. Although peanut agglutinin (PNA), which specific for galactoseß(1 ? 4)N-acetiylglycosamine structure, were not gave any histochemically important reaction, lectin blotting studies were indicated the existence of PNA-reactive bands in all three groups. Datura stramonium lectin (DSA), specific for galactoseß(1 ? 4)N-acetylglycosamine structures, were positively labelled in all age groups. Meanwhile, Galanthus nivalis lectin (GNA), which directed to terminal mannose residues, were not shown a staining pattern. This result shown that, sialic acid reactivity is altered with the organism?s age. This situation thought that (a) sialic acid containing glycoconjugates altered not only with erythrocyte senescence, but also aging process of organism or (b) the number of sialic acid containing erythrocytes was decreased by age.