Urgency. One of the leading factors in environmental degradation of the last decades is its contamination with radioactive substances, mainly those with a long half-life.
The objective of the research: to study the features of thiol-disulfide metabolism in the intestinal tissues of offspring obtained from chronically irradiated at low doses progenitors. Results. Studies have shown that under physiological conditions of existence there are clear gender and age differences in the functional state of the thiol-disulfide in the small intestine of males and females of different ages. It is established that prolonged total γ-irradiation in the total dose of 0.75 and 1.0 Gr causes quite stable and profound changes in the functional state of the processes under study. The dependence of the detected changes on the time elapsed after radiation damage, the dose of γ-irradiation and the sex of the animals is clearly traced. Females have been shown to be more radio resistant than males. to the same age intact animals by 15.6%. At the same time, there was a decrease in the activity of glutathione peroxidase and glutathione-S-transferase in the small intestine of male rats by 19.9 and 24.4% compared with the same age control. At the same time, the content of protein disulfide groups in the small intestine of irradiated males did not differ from the indicators of one-year control. There was an increase in the number of low molecular weight sulfhydryl groups by 35.6% compared to intact animals, while the content of disulfide groups of non-protein origin did not differ from the latter. The thiol-disulfide ratio of macromolecular compounds decreased relative to that of intact animals by 11.3%. The ratio of SH- to SS- in this case prevailed over the same age control by 72.4%. The detected changes are due to the occurrence of radiation-induced conformational ones, which prevent the interaction of SS-groups with the molecules of the corresponding substrates necessary for their reduction. Changes in protein sulfhydryl groups of small intestinal tissues in response to prolonged total γ-irradiation at a total dose of 1.0 Gr in males and females were almost the same, while shifts in protein disulfide groups differed significantly, i. e. in radiation-affected females macromolecular activity of thiol-dependent link of the antioxidant system is higher than in males. In females on the 12th day after irradiation at a dose of 1.0 Gr, compared with irradiated at a dose of 0.75 Gr, the content of protein SH-groups increased by 17.0%, the level of protein SS-groups by 15.7%, which in turn caused a decrease in redox potential. The differences in the changes of the thiol-disulfide system indicate a more intense course of thiol-disulfide metabolism reactions in females irradiated at a dose of 1.0 Gr compared to males. 3 months after prolonged total γ-irradiation at a total dose of 1.0 Gr in the small intestine of females, the content of sulfhydryl groups of protein origin was lower than the control by 17.8%. It should be emphasized that the detected shifts were significantly lower than in one-year-old irradiated males and rank over the latter by 24.5%. The number of disulfide groups of protein origin in the small intestine of females three months after radiation damage decreased relative to the previous term by 17.5%, but prevailed by 40.6% the level of control. The rather low level of sulfhydryl groups and high disulfide contributed to the reduction of the redox potential compared to the control by 42.5%, but with the indicators of the previous term it increased quite significantly. In irradiated females of this age, the content of sulfhydryl groups in the small intestine was higher than the control by 10.8%, and disulfide did not differ from the latter. It was also characteristic that the redox potential outweighed the control by 33.3%. Prolonged total γ-irradiation at a total dose of 1.0 Gr contributes to a fairly stable and significant changes in the thiol-disulfide system of the small intestine and the detection of shifts were more significant in males. The depletion of thiol-disulfide metabolism was quite noticeable, which was a sign of a decrease in nonspecific resistance in animals. Prolonged fractionated γ-irradiation at low doses causes long-term and stable shifts in the thiol disulfide system, the components of which, among other things, are responsible for the body's resistance to adverse environmental factors. The detected changes affect not only the tissues of the small intestine, but also the body as a whole. It is also characteristic that prolonged total γ-irradiation at a total dose of 1.0 Gr causes more significant changes than at a dose of 0.75 Gr, and this is especially evident in the longer term after its action. The latter is a consequence of depletion of the buffer capacity of anti-radical processes. Resistance of small intestine tissues to the effects of ionizing radiation in females is much higher than in males.
