HEMATOLOGY: Irreversible oxidant injury in the erythrocytes of the newborn infant

Abstract

It is generally recognized that the red cells of the newborn are more susceptible to injury, i.e. the appearance of Heinz bodies and glutathione instability, upon exposure to oxidant compounds. A more complete examination of the extent and nature of this injury was made. RBC's were incubated for 2 hours with and without glucose in the presence of acetylphenhydrazine (APH) or menadione (K3) and then reincubated in glucose media. Red cell hexokinase, phosphofructokinase, and glyceraldehyde-3-phosphate dehydrogenase activity, all SH containing enzymes, were irreversibly lost in the cells of the newborn when incubated in APH or K3 with no glucose in the medium. The cell's ability to consume glucose was reduced from 50 to 95%. The red cells of adults showed som fall in enzyme activity during drug exposure but full acitivity was restored and red cell glycolysis was unimpaired when reincubated in glucose. Incubation of the cells of the newborn in a carbon monoxide atmosphere during drug exposure prevented their adverse effects. In addition, in the presence of glucose, K3 increased the rate of fatty acid incorporation into adult cells and depressed the rate in newborn cells. Oxidant drugs apparently through alterations in the cells of the newborn and their use in the neonatal period appears contraindicated.