Membrane surface properties of reticulocytes from rats rendered severely anemic with phenylhydrazine as determined by partition in aqueous phase systems

Abstract

Partition was studied in aqueous dextran-polyethylene glycol two-phase systems of reticulocytes from rats rendered severely anemic with phenylhydrazine. 1. 1. The countercurrent distribution of reticulocyte populations from phenylhydrazine-injected rats indicate that these are highly heterogeneous. The distribution patterns obtained include separation of such reticulocytes into two distinct sub-populations, a broad (and therefore obviously heterogeneous) curve, or a distribution intermediate between these. 2. 2. A part of the heterogeneity of the reticulocyte population is due to the degree of maturation of these cells. Highly reticulated reticulocytes (with the highest protein synthetic activity) have the lowest, lightly reticulated reticulocytes an intermediate and erythrocytes the highest partition. 3. 3. The partition of reticulocytes is lower than that of normal erythrocytes and is thus similar to the partition of the youngest reticulocytes from normal rats [6]. Reticulocytes from phenylhydrazine-injected rats are shown to maintain this (low) partition while they age. They differ thereby dramatically from normal rat reticulocytes the partition of which increases rapidly as they mature. 4. 4. Reticulocytes from phenylhydrazine-injected rats (‘abnormal’ reticulocytes) do mature to erythrocytes. But these, in turn, have a lower partition than erythrocytes from normal rats. Surface charge is a major determinant of cell partition in dextran-polyethylene glycol phases. The lower partition of reticulocytes from phenylhydrazine-injected rats and of the erythrocytes into which they mature therefore reflects a lower surface charge on these cells compared to their normal counterparts. 5. 5. A large percentage of the abnormal reticulocytes disappears rapidly from the circulation both in the phenylhydrazine-injected animal and when transfused to normal rats. This rapid disappearance may well be related to the abnormal membrane surface characteristics of these cells.