Earlier studies using artificial lipid membranes demonstrated that fetal methemoglobin
exhibits enhanced oxidative interaction with liposomes compared to adult methemoglobin.
The present study extends these observations to biologically relevant erythrocyte membrane
systems. Adult and fetal methemoglobin were prepared by oxidation of hemoglobin A and
F, respectively. Erythrocyte membranes and erythrocyte ghosts were isolated from adult
donor blood and umbilical cord blood. The interaction of methemoglobin derivatives with
erythrocyte membraneswas studied by spectrophotometric monitoring of the Soret band and by
biochemical assessment of lipid peroxidation. Fetal methemoglobin induced more pronounced
oxidative alterations in erythrocyte membranes than adult methemoglobin, particularly in
neonatal membrane preparations. The obtained results confirm that fetal methemoglobin
exhibits enhanced oxidative membrane activity not only in model membranes but also in
ex vivo erythrocyte systems, providing mechanistic insight into neonatal susceptibility to
oxidative hemoglobin stress.
