[Some indices of trace elements and antioxidant status in rats under chromic intoxication].

There was investigated the effect of chronic Cr (VI) on the content of chromium, iron, copper; zinc, nickel in the blood of rats and activity of antioxidant enzymes of erythrocytes in Wistar rats. The chromium concentration has been shown to increase multifold while the level of other metal is more or less declining. Also it was found a decrease in the activity of such antioxidant enzymes as superoxide dismutase, catalase, and the activation of the processes of free radical oxidation. Thus, it can be assumed that the effect of Cr (VI) is implemented via an imbalance of trace elements and the activation of the processes of free radical oxidation.

Long-term effects of chromium on morphological and immunological parameters of Wistar rats.

Hexavalent chromium raises high concern because of its wide industrial applications and reported toxicity. Long-term (135 days) oral exposure of Wistar rats to chromium in the form of K2Cr2O7 (exposed group~20 mg/kg/day) led to a decrease in thymus mass and thymocytes' number and caused structural and functional changes in the lymph nodes and spleen, namely lymphoreticular hyperplasia and plasmocytic macrophage transformation. Programmed cell death was increased in both thymocytes and splenocytes and decreased in lymphocytes in the T-zones of spleen and lymph nodes. Moreover, Cr (VI) administration decreased myeloid cells' and neutrophils' number, while it increased lymphoid and erythroid cells' number in bone marrow. Cr (VI) immune system effects seem to be related to oxidative stress induction, as depicted by the increased levels of diene conjugates and malondialdehyde in the spleen and liver and by the decreased activity of catalase and superoxide dismutase in rats' erythrocytes. In addition, exposure to Cr (VI) decreased copper, nickel and iron concentrations in blood and liver, while Cr levels in blood, spleen and liver were increased, as expected. The observed changes in the series of immunological parameters studied contribute to the development of new approaches for the prevention of low level Cr exposure toxicity.

Immune and interferon status in schoolchildren living in cities with different anthropogenic load.

Examinations of 6-11-year healthy children living in industrial cities of the Orenburg region revealed a close relationship between ecological status of the territory and some immunity parameters such as immune deficiency, interferon content, and formation of postvaccinal immunity with live measles vaccine. The most pronounced changes in the immune status and decreased postvaccinal immunity were found in a city with the greatest anthropogenic load. Changes in interferon status were similar in all cities: a 2-fold increase of serum interferon and suppressed production of interferon-alpha and interferon-gamma.