EFFECT OF LONG-TERM LOW-INTENSITY IONIZING RADIATION AND COLD FACTOR ON MORPHOFUNCTIONAL INDICATORS OF THE ADRENAL CORTEX IN MOUSSEID RODS

Abstract

The adrenal gland occupies one of the central places in the regulation and implementation of such vital processes as growth, development, reproductive behavior and adaptation of the body to changing conditions of existence; it plays an important role in maintaining the body's resistance to adverse influences.. Any change in external conditions that require the intensification of metabolism affects in a certain way the functional activity of the adrenal glands. So, changes in morphological indicators of adrenal activity can be considered as an indicator of the functional tension of the body. The structure of adrenal glands is sensitive to the effects of various environmental factors, which has been shown in many works, but data on changes in the structure of adrenal glands in animals exposed to chronic exposure to a low-intensity radiation factor are extremely scarce. The problem of chronic exposure to radiation on living organisms is also of particular importance due to the variety of environmental, chemical and physical factors that, in combination with ionizing radiation, can cause a wide range of biological effects. It is very difficult to predict the results of such interactions; even the effects of their separate influence have not been sufficiently studied. In this regard, it becomes important to study the enhancement or weakening of the biological effect with the simultaneous influence of several factors. The aim of our study was to reveal the features of the histo-functional state of the adrenal glands under the combined effects of chronic ionizing radiation in small doses and the cold factor. During the first experimental series, voles were chronically exposed by ү-irradiation for 2 months and 4 months. Absorbed dose was 5.2–7.31 cGy respectively. During the second experimental series, voles were cooled at temperatures 0 оС and -10 оС, after which they were taken out of the experiment. During the third experimental series, we combined the types of exposure.. The control groups of voles were in the vivarium under normal radiation background and temperature – +20 оС. The study of morphological changes in the adrenal glands allowed us to reveal structural and functional reactive changes in the action of the studied factors, as well as to assess the functional reserves of the adrenal glands. The experiments were carried out on sexually mature males – descendants of voles, caught in areas with normal and increased radiation background (subzone of northern taiga, Uhtinskiy radium monitoring station, Komi Republic). The analysis of experimental studies revealed a general pattern, manifested in the form of activation of the secretory activity of the adrenal cortex. It was established that the severity of morpho-functional indicators of the adrenal glands increases in proportion to the strength and duration of exposure in the dynamics of the isolated action of the factor of chronic exposure and low temperatures, as well as their combined action. The conclusion is made about the possible significance of the synergistic interaction of hypothermia in enhancing the effects of chronic exposure. The results of our study contribute to understanding the cellular mechanisms of adaptation of root voles to radioactive contamination in the north, as well as the dependence of morphological parameters on additional impacts in the environment. The importance of adaptive rearrangements, a complex of structural changes in various systems of the body, namely, its adequate functioning and survival under the chronic action of stress factors, determines the priority direction of such studies.