[Comparative data on the glutathione and methemoglobin levels in the blood of pregnant and nonpregnant white rats inhaling NO2].

Nitrogen dioxide /NO2/, is one of the basic photochemical atmospheric pollutants possessing both direct and indirect toxic effects. When inhaled NO2 affects directly the blood hemoglobin forming methemoglobin. The rate of effect depends on the level of the intra-erythrocyte redox systems and in the first place on the reduced glutathione. The systemic toxic effects of NO2 and is easy penetration through the hemato-alveolar barrier are well known. However the effects of NO2 on the organism during pregnancy have nor been studied. The present study has been designed to evaluate the effect of NO2 on the reduced oxidized glutathione and the level of methemoglobin in the blood of pregnant and nonpregnant female rats. Inhalation exposure of pregnant albino rats to NO2 in concentration of 10 and 1 mg/m3, 5 hours daily, throughout gestation /21 days/, induces an increased synthesis of glutathione and shifting towards the reduced form, which could be taken as a sign of adaptive mechanisms. The nonpregnant animals show no such effect, as they more easily compensate the oxidizing effect of NO2. At the age of 1 month the progeny of the NO2-exposed mothers show the same tendency to an elevated synthesis of glutathione and increase of its reduced form. When treated again with NO2 at the same dose levels during gestation, the F1 females show no changes in blood glutathione, but the level of methemoglobin is raised--an effect not observed in the parental generation.