An Experimental Study of the Primary Mechanism of the Effects of Radiation on Cell Nuclei; EKSPERIMENTAL'NOE IZUCHENIE PERVICHNOGO MEKHANIZMA DEISTVIYA RADIATSII NA YADRO KLETKI

Technical Report · Mon Aug 28 04:00:00 EDT 1961

OSTI ID:4832310

Dubinin, N P; Sidorov, B N; Sokolov, N N; Mekshenkov, M I

The dose required to obtain a given effect on a dry material is much greater than the dose required to obtain the same effect in aqueous solution. An indirect effect of radiation is caused by the radiolysis of water to form OH and HO/sub 2/ radicals which react with the substrate. Free radicals can be produced with the use of radiation by reacting ferrous iron with H/sub 2/O/sub 2/ (Fenton's reagent) and by reacting ascorbic acid with H/sub 2/O/sub 2/. By immersing onion bulblets in 0.001 M FeSO/sub 4/ or 0.001 M ascorbic acid followed by immersion in 0.0l M H/sub 2/O/sub 2/, a powerful mutagenic effect was observed in that 17.7% chromosome rearrangements were observed with the use of Fenton's reagent. The percentages were 11.8% with the use of ascorbic acid plus H/sub 2/O/ sub 2/, 1-8% for FeSO/sub 4/ alone, 1.7% for ascorbic acid alone, 1.9% for water alone, and 5.8% for H/sub 2/O/sub 2/ alone. The addition of Kl to a ferric system resulted in a reduction of Fe/sup 3+ to Fe/sup 2+. Free radicals were then formed by treatment with H/sub 2/O/sub 2/, and a mutagenic effect could be detected (37.4% chromosomal rearrangements). It was found that iodide and bromide ions react with the free radicals produced by Fenton's reagent and by the reaction of ascorbic acid with H/sub 2/O/sub 2/, and decrease the mutagenic effect of these free radicals. Hydroquinone, quinone, hyposulfite and thiourea were also effective. However, these protective reagents do not protect the cells against genetic damage on irradiation with x-rays. Hence, the genetic effect of radiation is primarily due to the direct effect of a quantum of energy on the chromosome. However, it is pointed out that protective reagents may play an important role in decreasing the in direct effects of radiation by combining with free radicals, especially in dilute solutions. 87 references. (TTT)

• Research Organization: U.S.S.R. Sovet Ministrov. Gosudarstvennyi Komitet po Ispol'zovaniyu Atomnoi Energii
• NSA Number: NSA-16-002887
• OSTI ID: 4832310
• Report Number(s): A/AC.82/G/L.636
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANIMAL CELLS
ASCORBIC ACID
BIOLOGY AND MEDICINE
BROMIDES
CELL NUCLEI
CHEMICAL REACTIONS
CHEMICALS
CHROMOSOMES
ENERGY LEVELS
FREE RADICALS
HYDROGEN PEROXIDES
IODIDES
IONS
IRON COMPOUNDS
IRON SULFATES
MUTATIONS
PLANTS
RADIATION DOSES
RADIATION EFFECTS
RADIATION PROTECTION
SOLUTIONS
VITAMINS
WATER