[Mechanism of action of small doses of radiation]

Opposite changes occur in the intensity of UV-fluorescence (UVF) in irradiated (0.1 Gy and 5.0 Gy) HeLa cells. The radiometric study has demonstrated that there is a correlation between the number of tryptophan-containing proteins and UVF intensity in nonirradiated and irradiated (5.0 Gy) cells during culture growth. Such a correlation was absent in cells exposed to 0.1 Gy radiation. Low radiation doses (0.1 Gy) have maximum action on cytoplasm membrane fluorescence. Low-level radiation changes the intensity of the ANS probe fluorescence connected with cell membranes, and the intensity of the cell protein UVF. High radiation doses increase and low doses decrease the probe fluorescence.