OXYGEN SATURATION IN BONE MARROW, AND IN ARTERIAL AND VENOUS BLOOD DURING PROLONGED HEMORRHAGIC ERYTHROPOIESIS

Abstract

Anemia was induced in 8 o dogs by repeated small hemorrhages and this condition was maintained for 40-100 days. The anemia level was detd. from the O2 capacity, which was reduced to approx. 60% of the control value. Stimulation of erythropoiesis was demonstrated by the daily production of hemoglobin and reticulo-cytosis. Percentage 02 saturation of blood obtained from the red bone marrow of the unanesthetized animals and that from the femoral artery and jugular vein was measured before and during the anemia period. No significant difference was evident in the O2 saturation of bone marrow blood in the anemia period when compared with that in the control period. Arterial blood showed the same constancy in O2 saturation, but that of jugular venous blood decreased slightly in anemia. The evidence indicates that a striking and prolonged stimulation of erythropoiesis occurred even though the O2 saturation of bone marrow blood remained at normal levels. Certain aspects of the circulatory compensation in anemia are discussed with reference to arterial-marrow 02 content difference.