PERINATAL CHANGES OF 2,3-DIPHOSPHOGLYCERATE AND OXYGEN-AFFINITY IN MAMMALS NOT HAVING FETAL TYPE HEMOGLOBINS

The interrelationship of 2,3-diphosphoglycerate (2,3-DPG) and P50 levels during the fetal and postnatal life were determined in two mammalian species which do not have a switchover of hemoglobin type at the end of their fetal development. In the guinea pig and rabbit, the 2,3-DPG levels remain low during fetal life and increase only after birth remaining elevated throughout adult life. The adult levels were reached at 2 days of age in the guinea pig and the 20th day in rabbit. Fetal P50 values increased only after birth, paralleling the rise in the 2,3-DPG. The rapidity of the postnatal rise in 2,3-DPG and decrease in P50 appears related to the maturity of the newborn animal at birth in these species. Speculation: The synthesis of 2,3-DPG during fetal life appears to be limited. This limitation may be due to the lack of substrate or the key enzyme, 2,3-DPG mutase, during fetal development. © 1979 International Pediatric Research Foundation, Inc.