1959•OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information)Requires access
EFFECT OF IONIZING RADIATION ON DEOXYRIBONUCLEIC ACIDS. I. THE MOLAR RELATIONSHIPS OF DEOXYRIBONUCLEIC ACID BASES OF RAT HAEMATO-POIETIC TISSUE
E. Paleček
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Abstract
The author confirmed the increase in the ratio of purine and pyrimidine bases in DNA from the spleen of rats totalbody irradiated with a dose of 400 r and killed five days after irradiation. The DNA was isolated by a modification of the schmidt-Thannhauser method. A relative decrease in pyrimidine bases was also found five days after irradiation with doses of 200, 100, and 50 r. Even after these small doses the change was statistically significant. After 400 r changes were also observed in rat bone marrow. The composition of splenic DNA was studied immediately after and three, six, and 24 hours after irradiation with a dose of 400 r. No change in the ratio of the bases was found immediately after irradiation. Three hours after, only the adenine/thymine quotient was raised. Six hours after, an increase in the adenine/thymine and guanine/ cytosine quotient was observed. Twenty-four hours after irradiation changes in the A/T and G/C quotients approached the values found on the fifth day after irradiation. Since these changes occur so soon after irradiation, they are evidently not due to a disturbance of DNA synthesis. The author submits the hypothesis that they are due to enzymatic degradation of DNA.more » (auth)« less