Journal of Applied Physiology, Vol 68, Issue 3 938-943, Copyright © 1990 by American Physiological Society
Effect of hemoglobin solution on compensation to anemia in the erythrocyte-free primate
A. L. Rosen, S. A. Gould, L. R. Sehgal, H. L. Sehgal, H. D. Levine, R. D. DeWoskin and G. S. Moss
Department of Surgery, Michael Reese Hospital and Medical Center, Chicago, Illinois.
Hemoglobin solutions are undergoing clinical trials as erythrocyte
substitutes. Some of these solutions have higher O2 affinities compared
with normal erythrocyte hemoglobin. Also, they appear to interact with
endothelial-derived smooth muscle relaxation. The purpose of this study was
to evaluate the nature and limits of compensation to acute normovolemic
anemia in the erythrocyte-free primate maintained with a hemoglobin
solution. The experimental group consisted of six anesthetized paralyzed
adult baboons (Papio anubis) that were exchange transfused (ET) with a
pyridoxylated polymerized hemoglobin solution [hemoglobin concentration [(
Hb]) = 14 g/dl, O2 half-saturation pressure of hemoglobin (P50) = 19.6
Torr] until a hematocrit less than 1% was achieved. They underwent a second
ET with Dextran-70 until [Hb] = 1 g/dl. A control group (n = 6) underwent
an ET with Dextran-70 until [Hb] = 1 g/dl. Both groups maintained O2
consumption (VO2) until [Hb] = 3 g/dl. Both groups were stable until [Hb]
less than 1 g/dl, and both groups increased their cardiac output. The
relation between VO2 and O2 delivery was similar for both groups. In vivo
P50 and mixed venous O2 tension were significantly lower in the
experimental group. The nature and limits of compensation to diminished O2
delivery due to anemia were similar in the two groups.
