ABSTRACT
Objective: To evaluate the possible relationship between industrial air pollution and oxidative stress in schoolchildren by comparing parameters from children residing in two nearby localities with contrasting environmental conditions. Participants: 42 schoolchildren (12-15 years) from Pancevo (site of Serbia’s largest petrochemical installation) formed the exposed group. 82 schoolchildren from Kovacica village, located 30 km north of Pancevo, formed the non-exposed group. Methods: Oxidative stress status, anti-oxidative defense parameters, paraoxonase-1 status, lipid status, glucose concentration and leukocyte counts were compared in two groups. Results: The children from Pancevo showed higher level of oxidative stress demonstrated by an elevated malondialdehyde concentration (P <0.001) and decreased superoxide dismutase activity (P<0.01) in comparison to the non-exposed group. Conclusions: The results suggested a relationship between the presence of air pollutants and increased oxidative stress in schoolchildren residing in an industrial environment.
ABSTRACT
In order to better understand the mechanisms affecting erythropoietin (Epo) synthesis and red cell mass increase under chronic hypoxia, we examined Epo production and erythroid progenitors (CFU-E) in rats exposed to normobaric hypoxia for four weeks. Hypoxia induced the rise of hematocrit (Htc), hemoglobin (Hb) concentration and the red blood cell (RBC) number with a plateau in hematocrit values after two weeks. After 24 h of hypoxia, Epo levels were increased 20 fold, followed by a significant decrease. After the first week of hypoxia, the values were still higher than in the controls, but after two weeks Epo levels did not differ significantly from the normal values. The fall of Epo levels coincided with the plateau values of hematocrit. The changes in the CFU-E number followed the changes in Epo concentration: a two fold increase after 24 h of hypoxia; a further increase during the next two weeks reaching a peak on day 14, and then a progressive decrease at the time when Epo concentration was at a normal level. Although decreased, but still higher than normal, the CFU-E number during the last two weeks of hypoxia could be necessary for the maintenance of an achieved steady state under persistent hypoxic conditions with normal Epo concentration sufficient to maintain the existing rate of erythropoiesis.