Temporal changes in the oxidation state in in vitro blood.
The rates at which the paramagnetic compounds deoxyhemoglobin (Hb) and methemoglobin (MHb) form in vivo within an area of hemorrhage are unknown. The present experiment establishes the baseline concentrations and rates of change in paramagnetic hemoglobin concentrations, as well as the pH in normal heparinized and clotted human blood maintained in vitro at 37 degrees C under anaerobic conditions over 30 hours. There was a moderate increase in Hb concentration in normal heparinized blood (average increase was 15.5%, rate = 0.50%/hour) and a slight increase in MHb concentration in the heparinized blood and clots (average increase was 1.4%, rate = 0.044%/hour). A second experiment was done to verify the activity of the RBC systems responsible for maintaining the hemoglobin molecule in the reduced state. Conversion of MHb to Hb in these samples proceeded at a rate of 5.6%/hour. In a third experiment, blood from 11 normal subjects maintained at 4 degrees C 25 degrees C was analyzed for MHb concentration over the course of 28 days. The level of MHb formation remained in the range of normal for at least 11 days in all subjects. The authors conclude that at basal conditions created in vitro, the blood levels of both Hb and MHb remain at relatively low levels. Therefore, if the accumulation of Hb and/or MHb occurs in acute in vivo hematomas it must be driven by intrinsic tissue factors.
Taber
K H
KH
Department of Radiology, Baylor College of Medicine, Houston, Texas.
Migliore
P J
PJ
Pagani
J J
JJ
Ford
J J
JJ
McLauren
T
T
Hayman
L A
LA
D002543:Cerebral Hemorrhage / Q000097:blood*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008706:Methemoglobin / Q000032:analysis; D010084:Oxidation-Reduction; D010108:Oxyhemoglobins / Q000032:analysis
D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D008706:Methemoglobin