Effects of chronic exposure to radiation in different periods of ontogenesis on the occurrence of micronuclei in thyroid cells

With the micronucleus test analyzes cells of the thyroid gland (TG) in animals from natural populations and laboratory CBA mice exposed to ionizing radiation in low doses in different periods of ontogeny. It has been found increased formation of cells with micronuclei in thyroid vole-housekeeper living on radioactive sites compared with animals from the control plot. In the experiment on mice that develop the chronic effects of low-intensity γ-radiation (8 cGy) during early ontogeny also is an increase in the number of follicular thyrocytes with micronuclei. Chronic exposure of adult mice of the same total absorbed dose as in the previous embodiment, the experiment did not cause genotoxic effect in cells of the thyroid gland.