The significance of thyroxine in the processes of interaction of corticosteroids with plasma proteins on the model of resistance of irradiated animals with autotransplanted adrenal glands

The article is devoted to the study of the thyroxine effect on protein-steroid interaction in irradiated animals with autotransplanted adrenal glands. The relevance of the study is due to the need to study the radiobiological patterns of pituitary-thyroid regulation of protein-steroid interaction in acute radiation sickness in conditions of increased radioresistance of the body. The purpose of the work is to study the effect of thyroxine on the fractional composition of 11-hydroxycorticosteroids (11-OCS) and the binding capacity of corticosteroid binding globulin (CBG) in irradiated animals with autotransplanted adrenal glands. For experimental work 60 male rats weighing 200-220 g were used. Groups of animals with autotransplanted (experiment) and intact (control) adrenal glands were formed. Autotransplantation of the adrenal glands was performed according to the method of D. Ingle and G. Higgins. All animals were irradiated at a dose of 6.0 Gy. Animals in the experimental groups were administered 50 μg of thyroxine LD (Reanal, BP). Animals in the control groups were injected intraperitoneally an equal volume of physiological solution. To assess protein-steroid interactions, the fluorometric method, gel filtration method in the author's modification, a method for measuring the weight of the thymus were used. Conclusions were drawn about the effect of thyroxine on the protein-steroid interaction in radiation sickness using a model of resistance in irradiated animals with autotransplanted adrenal glands: 1) under the influence of thyroxine, the level of free 11-OCS in intact irradiated rats increases to a greater extent than the binding capacity of CBG; 2) administration of thyroxine to animals with autotransplanted adrenal glands causes an increase in the binding capacity of CBGs and a significant decrease in the concentration of free 11-OCS in the blood plasma; 3) the positive effect of thyroxine administration on increasing the weight of the thymus was manifested only in animals with autotransplanted adrenal glands; 4) an increase in the weight of the thymus in irradiated rats with autotransplanted adrenal glands under the influence of thyroxine is associated with a decrease in the content of unbound 11-OCS in the blood of animals.