Glycosylated and Acetylated Hemoglobins in Relation to Gestational age and Red Cell age

Abstract

Cord blood samples were obtained at delivery from women at gestational periods of 30 to 36 weeks (preterm) and from a control group at 40 weeks of gestational age (term). Total glycosylated hemoglobin (GHb) was determined by affinity chromatography and the percentages of the minor Hbs F and F (of total Hb F) were determined by Bio-Rex 70 chromatography in whole blood samples and in red cell populations separated by Dextran 40 density gradient centrifugation. The absolute levels and the increase due to red cell aging of GHb, Hb F_Ia+b and Hb F_Ic were significantly reduced in the preterm samples compared to the term samples indicating decreased glycosylation in preterm fetus. When the nonglycosylated Hbs from term and preterm newborns were separated by Bio-Rex 70 chromatography after removal of the GHb by affinity chromatography, the acetylated form of Hb F_Ic also showed an increase with red cell aging indicating posttranslational enzymatic or nonenzymatic acetylation of Hb F during the entire life span of red cells. Moreover, as with GHb, the acetylated Hb was also decreased in the preterm newborns.