[Effect of sodium selenite on the activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase) during hepatocarcinogenesis].

Influence of sodium selenite on functioning of the systems of intracellular generation and detoxication of active oxygen compounds in hepatocarcinogenesis induced by diethylnitrosamine has been studied in experiments on rats. It has been shown that the duration of latent period initiated by ions of Fe2+ chemiluminescence of homogenate of the liver rather objectively reflects the state of the functioning of the systems in charge of the formation and utilization of free radicals of oxygen in a cell. It is supposed that one of the mechanisms of anticarcinogenic action of selenium is connected with its antioxidant functions in the organism and consists in the increase of the activity of superoxide dismutation and selenium-dependent glutathione peroxidases, providing a reliable level of enzymatic protection of normal cells from disturbing action of "active oxygen".

[Dynamics of the selenium content and selenium-dependent glutathione peroxidase activity in mice and rats with transplantable tumors].

Guerin's adenocarcinoma in rats and Ehrlich ascites tumor in mice involved loss of selenium in visceral organs matched by its simultaneous accumulation in tumor tissue. The activity of selenium-dependent glutathione peroxidase was found to increase. The said changes seem to be due to antioxidizing properties of selenium.

[Effect of selenium on the system of superoxide anion radical formation and detoxication in hepatocarcinogenesis].

It is established that the introduction of selenium in combination with diethylnitrosamine into rat organisms has a preventive influence on the tumour formation. The intensity of superoxide radicals formation by the liver cell microsomes in this case decreases, while the activity of superoxide dismutase, glutathione peroxidase I, glutathione reductase and concentration of selenium in microsomes increases. The anticarcinogenic action of selenium is considered as a result of an increase in the activity of superoxide dismutase, glutathione peroxidase I and glutathione reductase.