Journal of Applied Physiology, Vol 41, Issue 6 900-904, Copyright © 1976 by American Physiological Society
Sodium o-iodobenzoate and hemoglobin-oxygen affinity: in vivo effects
S. B. Litwin, W. F. Skogen, S. R. McCreadie and M. B. Laver
Sodium o-iodobenzoate (OISB) was given intravenously to 15 dogs to test the
in vivo effect of this drug on the oxyhemoglobin dissociation curve.
Administration of a single dose of 500 mg/kg was followed by an average
increase in P50 (PO2 at 50% oxyhemoglobin saturation) of 3.6 mmHg from 26.8
+/- 0.5 to 30.4 +/- 1.8 mmHg (corrected to pH 7.4). This elevation was
sustained for 7 days. During intravenous infusions of 200 mg/kg every other
day for 3 wk, there was a sustained increase in P50 of 2.6 mmHg from 27.8
+/- 1.1 to 30.4 +/- 0.9 mmHg. All dogs survived the experiment and no ill
effects of the drug were noted. An increase in serum lactate and pyruvate
occurred in all animals following acute or chronic exposure to the drug.
There was no significant change in whole blood pH, 2,3-diphosphoglycerate
concentrations, intracellular pH, or serum total phosphate. Multiple
infusions of sodium cyanate (50 mg/kg per day) reduced P50 by an average of
12.2 +/- 0.3 mmHg. A subsequent single infusion of OISB (500 mg/kg) failed
to increase P50. Our preliminary data indicate that pharmacological
manipulation of hemoglobin O2 affinity is possible with organic compounds
unrelated to erythrocyte metabolism.
