To investigate the possibility that the influence of hemoglobinoxygen
affinity on tissue oxygenation may be reversed in severe hypoxia, 16
anesthetized rabbits with chronically-implanted tissue oxygen electrodes were ventilated
with 12% oxygen and subjected to 100 ml exchange transfusions with high,
low, or normal affinity rabbit blood. Despite the widely divergent in vivo P(50)
values produced, significant differences in tissue oxygen levels were not observed
among the three groups following exchange transfusions. During subsequent normoxia,
more complete recovery of tissue oxygen was apparent in the low affinity
group. This study emphasizes the need for further definition of the influence of
hemoglobin-oxygen affinity on the functions of individual organs.