[Hypophyseal-adrenocortical system reaction to the prolonged action of low doses of selenomethionine-75Se that form during internal contamination].

A method of radiometry in vivo was applied to study the regularities attending distribution of the absorbed dose and its formation in the course of one year after the administration of 0.033 muCu/g of selenomethionine-75Se to rats, as well as the functional condition of the adaptive hypophysis-adrenal glands system by the determination of plasma corticosterone. A high tropicity of this preparation to the endocrine system organs was demonstrated. Intensification of the functional activity of the adaptive system was indicated by an increase of the blood plasma corticosterone concentration following the administration of a, radioactive preparation and its statistically significant increase (in comparison with control) 3, 6, and 10 months from the beginning of the experiment. The action of acute stress (histamine and formalin) 10 months after the administration of selenomethionine-75Se caused no sharp elevation of the plasma corticosterone concentration characteristic of control rats, this indicating an extreme strain of the hypophysis-adrenal gland system and its incapacity to respond to additional loads. It is supposed that analysis of functional condition of the adaptive system could serve as the key in the assessment of the biological effect of low radiation doses.