[Cholesterol and fatty acids of the nuclei and chromatin of the rat thymus at long intervals following gamma irradiation].

The content of a total fraction of free fatty acids (FFA) and cholesterol in the chromatin, nuclei and homogenate of rat thymus were studied during three months following fractionated gamma-irradiation (2 Gy X 3 at a week interval). The FFA content in the homogenate, nuclei and chromatin of rat thymus drastically increased 60 min after the last exposure. In a month, the FFA content of nuclei and chromatin dropped to control levels, whereas that of the homogenate remained high throughout the entire period of observation and sharply increased by the third month. No changes were revealed in the cholesterol content.