Variations in erythrocyte enzymatic activity in the first days of life [Variazioni di attività enzimatiche eritrocitarie nei primi giorni di vita]

The erythrocyte activities of glucose 6-phosphate dehydrogenase, pyruvate kinase and glucose phosphate isomerase decrease during the first days of life. Furthermore the level of these enzymatic activities is higher in newborn infants with higher percentage of carboxyhemoglobin. It is likely that a premature and rapid fall of reticulocytes causes a decrease in enzymatic activities sensitive to aging and that the higher hemolysis can represent a disappearance of oldest erythrocytes which present lower enzymatic activities. These data therefore confirm the block in erythropoiesis in the first hours of life.