Physiological red cell, 2,3-diphosphoglycerate increase by the sixth hour after birth.
As the available hemoglobin A1 at birth ranges from 20 to 30% a possible mechanism to favor oxygen release to the tissues could be a decrease of hemoglobin A1 affinity to oxygen. This may be accomplished by an increase in blood pH soon after birth and by an elevation in red cell 2,3-diphosphoglycerate (2,3-DPG). This hypothesis is supported by Valleri and Hirsch, who described a rapid 2,3-DPG recovery of transfused depleted 2,3-DPG red cells. That being so, we carried out this current study by assaying the 2,3-DPG of cord blood from 22 newborns and at 6, 24 and 72 hours after birth, as well as those enzymes assumed to be envolved in the 2,3-DPG levels regulation. 2,3-DPG (nmoles g-1 Hb) demonstrated the following values: cord blood: 9,770 +/- 1,026; 6h: 12,773 +/- 1,726; 72 h: 11,990 +/- 728, unveiling a distinct behavior of a sharp increase of 30% by the sixth hour. This confirmed our hypothesis. Regarding the metabolic mechanisms which can account for the 2,3-DPG increase, besides the rise of blood pH, we detected a significant decrease of the 2,3-DPG phosphatase activity, which might diminish the 2,3-DPG breakdown.
Barretto
O C
OC
Institute of Psychiatry LIM-23, University of São Paulo Medical School, Brazil.
Nonoyama
K
K
Deutsch
A D
AD
Ramos
J L
JL
D019794:2,3-Diphosphoglycerate; D004163:Diphosphoglyceric Acids / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism*; D005312:Fetal Blood / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D007700:Kinetics
D004163:Diphosphoglyceric Acids; D019794:2,3-Diphosphoglycerate