Variability of magnitude of the Bohr effect in human fetal blood

¹ Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, Utah

A series of in vitro determinations, conducted on human fetal blood obtained at the time of delivery, of percentage oxyhemoglobin saturation, partial pressure of oxygen, and pH have made possible the evaluation of the magnitude of the Bohr effect in that substance. Analysis shows that the Bohr effect, defined as log pO₂/pH, is a variable function of percentage oxyhemoglobin saturation over the statistically significant range in this study, from 10 to 87% saturation. The implications of this variability in terms of the molecular alterations of hemoglobin in the course of progressive oxygenation and in particular regard to the manifest heterogenicity of heme with respect to oxygen-acid radical interactions are discussed.