Radioactivity and life. YK Kudrytski (MD) 1971 Part 18.

Long-term studies of chronic low-dose radiation, provedeinye in our laboratory have revealed changes in many aspects zhiziedeyagelnosti experimental animals exposed to radiation doses equal to and close to the maximum allowable.
Among the many pokavateley life, ieuchavshihsya in these experiments was determined by the frequency of chromosomal aberrations klstk 13 s bone marrow and corneal epithelium semerodnom epithelium.
Spontaneous level of chromosomal aberrations in adult white mice. hook the same as a person, to a certain age rather constant. With 9-12 months of age in mice and humans with 35-40 years of age comes an increase in spontaneous levels of chromosomal aberrations. By the way, so rotation
. Chi is recommended to have children at younger ages.
Under the influence of chronic exposure enhanced age-related changes the frequency of chromosome aberrations. Until the early period of their age increase in the irradiated animals the frequency of chromosome 'aberrations almost unchanged and no different from the level in even-aged non-irradiated animals. Chronic exposure [age-related changes increases the frequency of chromosomal aberrations at a time when their frequency in the control, unirradiated
naninaet mice increases with age. . .
in these studies revealed another interesting feature reagnrovaniya organisms to long exposure to radiation in small doses. Strengthening aging changes the frequency of chromosome aberrations was the boleevyrazheno, the higher the daily dose of power.
In the same way to change the frequency of chromosomal aberrations in cells of the corneal epithelium and seminiferous tubules, the TTS can be considered a characteristic feature of the identified and other body tissues.
Results provedeinyh studies have shown that during long years of exposures that are appropriate occupational exposure to radiation, cytogenetic changes right does not depend on the total accumulated dose. The pattern of changes corresponds to the age patterns of cytogenetic changes in non-irradiated animals. Effect of chronic exposure to low doses appears only in the period of the age increase in the frequency of spontaneous chromosomal aberrations. Prior to this period, in adulthood, chronic radiation exposure in the 'doses visible "manner does not affect the frequency of chromosomal rearrangements. This fact indicates the existence of a threshold zavisimostn pitogeneticheskih radiation changes.
These features of cytogenetic changes, as shown by studies, are a reflection of the general laws of animal response to small long-term exposure to radiation, close to the maximum permissible level. The same dependence on the physiological regulation and the level of radiation exposure was found in the study of 'the processes of physical development, reproduction, physiological regeneration of cells and tissues, and immunogenee, hematopoiesis, the functional state of the nervous system and the overall reactivity of the animals. With respect to changes in all these processes, as well as for cytogenetic, was characterized by an absence. direct proportion to the total doses. '
The leading role of the physiological patterns of activity in the biological response to long-term radiation exposure at low doses, the dependence of these reactions on the level. exposure to radiation, ie, the dose rate and the lack of