Endogenous carbon monoxide production in patients with hemolytic anemia.

Abstract

It is desirable in many studies to be able to rapidly measure rates of erythrocyte and hemoglobin destruction. Labeling techniques have been utilized for this purpose but have the disadvantage of requiring several days' to weeks to obtain the desired data plus the hazards of radioactive isotopes. Estimations of hemoglobin turnover from measurements of fecal bile pigment or serum bilirubin concentrations contain large sources of error (1). Studies in which bile pigment is collected via bile duct fistulas have been of value in animal experiments (2) but are -not usually possible in man, and subjects who have bile fistulas cannot be called normal. At the present time it appears that many in vivo investigations of red cell survival in patients with hemolytic disease are limited by the lack of a precise rapid method for detecting changes in the rate of red cell destruction.It has been shown previously (3-9) that CO is an in vivo catabolic by-product of hemoglobin and

Use of alveolar carbon monoxide to measure the effect of ribavirin on red blood cell survival†

“…However, breath CO originating from heme metabolism (endogenous CO) must be distinguished from CO of environmental origin (exogenous CO). Initial reports using CO to assess RBC turnover required that subjects rebreathe into a closed system for several hours to distinguish exogenous from endogenous CO [18][19][20]. In the present study, we utilized a simplified technique in which the difference between the CO concentration of alveolar air and atmosphere was used to quantitate endogenous CO excretion rate (and RBC survival) [10].…”

Direct Relationship of Fetal Carboxyhemoglobin with Hemolysis in Alloimmunized Pregnancies

“…air pollution and cigarette smoke, 75-85% of the CO measured as HbCO in blood is endogenously derived from erythrocyte breakdown (3,4). Elevated HbCO levels have been associated with a variety of pathologic hemolytic conditions, among them hemolytic disease of the newborn (22)(23)(24). In the absence of exogenous CO sources, HbCO blood levels in nonpregnant individuals reflect the combined dynamic effects of CO production and elimination and of HbA's affinity for CO.…”

Use of pulmonary hydrogen (H2) measurements to quantitate carbohydrate absorption

“…The rate of pulmonary H, excretion in human subjects was measured by having the subject breathe for a 3-6 hr period into a closed system somewhat similar to that described by Coburn, Williams, and Kahn (3). The subject sat on a chair and his head was enclosed in a polyvinyl hood which was sealed at the neck with a rubber diaphragm.…”