Changes in Activities of Some Enzymes during in Vivo Aging of Mouse Erythrocytes

Abstract
Red cell G-6-PD [glucose-6-phosphate dehydrogenases, 6-PGD [6-phosphogluconate dehydrogenase], and GOT [glutamic-oxalacetic transaminase]were studied in mice during and after prolonged arrest of erythropoiesis by means of repeated subcutaneous injections of actinomycin D. No clear downward trend in the activities of any of these enzymes in the progressively aging cells was found except for GOT, which initially declined as the retic-ulocytes disappeared and then stabilized at a new lower level. Discontinuation of the drug evoked a marked reticulocytosis accompanied by a sharp increase of G-6-PD and GOT activity. These data suggest that the major factor determining the red blood cell enzymes level is the presence or absence of reticulocytes.