ON THE ROLE OF REACTIONS BETWEEN FREE CYSTEINE AND PEROXIDES IN BIOLOGICAL EFFECTS OF IONIZING RADIATIONS

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Radiobiologiya (U.S.S.R.) For English translation see Radiobiology (Engl. Transl.)

OSTI ID:4636823

Benevolenskii, V N

Due to the assumption that sulfhydryl compounds exert prophylactic action during irradiation by neutralizing the primarily arising radicals or by way of the creation of hypoxia, thus reducing the yield of secondary radicals and peroxides; the biological significance of reactions between sulfhydryl compounds and peroxides being formed is of particular significance. A study was made of the effect of hydrogen peroxide and urea peroxide on irradiated and unirradiated cells of Saccharomyces vini, Megri-139-B strain, acted upon simultaneously by free cysteine. Suspensions of yeast cells were supplemented with cysteine, or one of the peroxides, or both simultaneously. After 15-20 min the cells were irradiated with Co/sup 60/ gamma rays at doses of 30 and 50 kr, at a dose rate of 400 r/min. Samples were thin cultured on plates for 4-5 days at 30 deg . The percentage of cells in which division was inactivated by the radiation was determined in relation to the unirradiated control to which no substances were added by colony count. It was found that free cysteine added in the amount of 10/ sup -3/M and more to the suspension of irradiated and unirradiated yeast cells treated with hydrogen peroxide and urea peroxide intensifies the effect of inhibition of cell division by peroxides. It is suggested that this possibly occurs at the expense of chemically reactive radicals formed upon reaction of peroxides and cysteine. Peroxides alone intensify radiation injury only in the presence of toxic or subtoxic concentrations. Peroxides added in nontoxic concentrations before irradiation apparently exert a weak protective action on the inactivation of cellular division of yeast and intensifies the antiradiation action of cysteine. (H.M.G.)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-17-037094
• OSTI ID: 4636823
• Journal Information: Radiobiologiya (U.S.S.R.) For English translation see Radiobiology (Engl. Transl.), Journal Name: Radiobiologiya (U.S.S.R.) For English translation see Radiobiology (Engl. Transl.) Vol. Vol: 3; ISSN RADOA
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

BIOLOGY AND MEDICINE
COBALT 60
CYSTEINE
FREE RADICALS
GAMMA RADIATION
HYDROGEN PEROXIDES
MITOSIS
OXIDES
PEROXIDES
RADIATION DOSES
RADIATION INJURIES
RADIATION PROTECTION
SACCHAROMYCES
UREA
VARIATIONS
YEASTS