Fe(2+)-initiated chemiluminescence in rats with high hemoglobin-oxygen affinity during fever

The effect of high hemoglobin-oxygen affinity (HOA) on chemiluminescence initiated by Fe2+ was studied in rat plasma and red cell ghosts during fever. The high HOA was induced by daily ingestion of sodium cyanate with drinking water for 8 weeks. Rats with high or normal HOA received i.p. lipopolysaccharide Salmonella typhi (LPS). The half-saturation oxygen pressure (p50) after 240 min of fever was 23.3 +/- 0.7 in cyanate-treated rats comparing with 30.4 +/- 0.4 Torr in the group received placebo. The maximal value of initiated chemiluminescence rose in plasma and red cell ghosts of rats with normal HOA by 26.5 and 27.5%, respectively, and in rats with modified HOA by 17.1 and 23.8%, respectively. The antioxidant activity of plasma and red cell ghosts decreased under high HOA to a less extent. These investigations show that the lowering of oxygen flux to tissues due to hemoglobin carbamylation may decrease the production of free radicals in rats during fever.