[Transformation of erythrocytes and their ultrastructure with respect to aging]

Transformation and ultrastructure of erythrocytes have been investigated in 58 white non-inbred rats on the 1st, 2nd, 3d days after birth and at the age of 1.5, 3, 8, 20 months. The transformation index of the erythrocytes drops by the 8th month of life and further it rises in old animals. In newborn rats echino-poikiloid forms predominate; they are mainly presented as reticulocytes with remnants of nuclei, mitochondria and other organells. During first three days of life cells of the erythroid line actively free themselves from the nucleus by means of its pyknosis and chromatinolysis. In newborn rats erythrocytes have folds of plasmolemma of linear and spotted form on their surface; their number sharply decreases in mature animals. The least changes in form and ultrastructure of erythrocytes are noticed in 3-8-month-old animals.