Behaviour of cell physiological and biochemical indicators of maturation and aging of red blood cells in density fractionated red blood cells during a bleeding anaemia of the rabbit.

Changes of the density, MCV, MCHC, RNA-concentration and the activities of the enzyme G6PD and ASAT due to maturation and aging of rbc were investigated by repeated density gradient separation of these cells during a bleeding anaemia of the rabbit. The mean density of reticulocytes and erythrocytes decreases during the course of the anaemia by 14 and 10 g/l respectively. The difference between the density of both cell types increases from 3 to 6 to 12 g/l during the anaemia. Maturation and aging of rbc are characterized by an increase of the MCHC from 200 to 350 g/l cells and the decrease of MCV by 10-25%. The RNA concentration and the ASAT activity show an almost parallel behaviour in cells of different densities during the anaemia. Remarkable differences are observed between the ASAT activity and the G6PD activity: The G6PD activity decreases mainly during the aging process and almost not during the maturation, while the ASAT activity falls constantly during maturation and aging. As observed in former studies we could distinguish and isolate 4 characteristic populations of reticulocytes in certain density fractions during the anaemia: Normal young reticulocytes, line 2 reticulocytes, megaloreticulocytes and reticulocytes of high density.