J. Angulo et al., Impairment of endothelial relaxations by glycosylated human oxyhemoglobin depends on the oxidative state of the heme group, GEN PHARM, 32(4), 1999, pp. 475-481
While nanomolar met- or cyanomethemoglobin, either non-glycosylated or glyc
osylated, did not alter endothelial function, glycosylated oxyhemoglobin in
duced contractile responses and caused an impairment of endothelium-depende
nt relaxations in rat aortic segments. The vascular effects induced by glyc
osylated oxyhemoglobin were prevented by superoxide dismutase. Furthermore,
glycosylated oxyhemoglobin produced higher amounts of superoxide anions th
an other hemoglobin derivatives. These results suggest that glycosylated he
moglobin requires the existence of a functional heme group containing iron
in ferrous state to interfere with the endothelial function at nanomolar co
ncentrations. This effect is mediated by generation of superoxide anions. (
C) 1999 Elsevier Science Inc. All rights reserved.