On the problem of impaired binding of corticosteroids to blood plasma proteins in the pathogenesis of acute radiation sickness

Abstract

The study of violations of the binding of corticosteroids to blood plasma proteins in acute radia-tion syndrome allows us to clarify the mechanisms and patterns of pathological changes in the hormonal level of the body in the pathogenesis of acute radiation sickness. The relevance of the study is determined by the current risks of new man-made disasters and the threat to radiation safety. The results of the study make it possible to expand a number of theoretical positions of radiobiology on the main regularities of the binding of corticosteroids to blood plasma proteins, taking into account its various fractions, which make it possible to determine the role of free corticoids in the hormonal effect in acute radiation sickness. The purpose of this work is to study the main patterns of binding of corticosteroids to blood plasma proteins in the pathogenesis of acute radiation sickness in animals. The experiments were carried out on 20 male rabbits and 475 outbred rats. Previously experimental animals were adapted to the conditions of the experiment. The total gamma-irradiation of animals was carried out on the EGO-2 unit at an average dose rate of 575 R/min. Rabbits were irradiated at a dose of 8 Gy, rats at a dose of 8,5 Gy. The total content of 11-OCS was determined by the fluorimetric method in the author's modification. The amount of free corticosteroids was determined by the difference in their content in whole plasma and in its pro-tein fraction after separation on Sephadex G-25. Results have been obtained demonstrating changes in the fractional composition of 11-OCS in blood plasma in the pathogenesis of acute radiation sickness in animals with mono- and biphasic curves of adrenocortical response to irra-diation. Disturbances in the binding of corticosteroids to blood plasma proteins were found, resulting in an increase in free, biologically active hormones in the midst of radiation sickness. The presence in the blood plasma of non-protein-bound and therefore more mobile steroids can cause a hypercorticoid state with normal or even reduced levels of hormones in the blood. The long-term effect of "hidden" hypercortisolism, therefore, may be a factor that aggravates the clinical course of acute radiation sickness.