Red Cell Oxygen Affinity, Hemoglobin Type, 2,3-Diphosphoglycerate, and pH as a Function of Fetal Development

[摘要] Studies were carried out on fresh cord blood obtained at delivery from nonstressed normal fetuses ranging from 24 to 42 weeks of gestation, to determine the relationship of 2,3-diphosphoglycerate (DPG), the intracellular red cell and extracellular pH, and the proportions of adult and fetal hemoglobin in regulating the position of fetal red cell oxygen affinity in utero. There was a significant positive correlation between P50 and gestational age ( r = .62, P < .001), the linear regression increased from 17.8 to 22.5 mm Hg. There was also a significant positive correlation between P50 and the percentage of adult type hemoglobin (HbA) ( r = .67, P < .001). In contrast gestational age had no effect of 2,3-DPG levels, the mean and SD was 14.86 ± 2.04 mol/gm of Hb or ΔpH between plasma and red cell, the mean was 0.187 ± SD 0.032. However, there was a significant negative correlation between the intraerythrocyte hydrogen ion concentration and DPG level ( r = .5, P < .025). It is concluded therefore that the decrease in fetal oxygen affinity as gestation progresses is related mainly to the increase in the amount of HbA and the levels of DPG or ΔpH between plasma and red cells are not a function of gestational age.

[学科分类] 儿科学