Glutathione plays a key role in maintaining a physiological balance between prooxidants and antioxidants in the human body. Therefore, we examined the influence of maternal smoking as a source of oxidative stress measured by total oxidant capacity (TOC) on reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione peroxidase (GPx-3), and reductase (GR) amount in maternal and umbilical cord blood in 110 (45 smoking and 65 non-smoking) mother-newborn pairs. Concentrations of glutathione status markers and TOC were evaluated by competitive inhibition enzyme immunoassay technique. Plasma TOC levels were significantly higher and the GSH/GSSG ratio, which is considered an index of the cell's redox status, were significantly lower in smoking women and their offspring than in non-smoking pairs. Decreased GR levels were found in smoking mothers and their newborns compared with similar non-smoking groups. Although plasma GPx-3 concentrations were similar in both maternal groups, in the cord blood of newborns exposed to tobacco smoke in utero they were reduced compared with the levels observed in children of tobacco abstinent mothers. Oxidative stress generated by tobacco smoke impairs glutathione homeostasis in both the mother and the newborn. The severity of oxidative processes in the mother co-existing with the reduced potential of antioxidant systems may have a negative effect on the oxidative-antioxidant balance in the newborn.
Keywords: cord blood; glutathione; glutathione peroxidase; glutathione reductase; smoking in pregnancy; total oxidant capacity.