DIRECT AND INDIRECT BIOLOGICAL EFFECTS OF RADIATION

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Arch. Hyg. u. Bakteriol.

OSTI ID:4816947

Hobitz, H

The primary physical processes, ionization and excitation, induced by radiation in biological materials are discussed. Their effects in causing reduction, decarboxylation, and depolymerization in proteins and deoxyribonucleic acid of the cell nucleus are examined. The action of radiation doses of 100,000- 600,000 r on pollen of Digitalis purpurea maintained at room temperature and at approximates 190 deg C showed that biological activity was destroyed by doses >200,000 r at room temperature, but at approximates 190 deg the pollen retained some activity even after the highest dose. A similar effect was seen with Bacterium cadaveris cells, about 0.5% of which survived 50000 r given at l8O deg whereas no cells survived 20000 r given at 4 deg . The presence of 1% cysteamine at the higher temperature increased survival 20-fold. Cytochrome c showed markedly different responses to radiation in dry form as compared with aqueous solution. The anhydrous enzyme showed a linear decline in log activity with radiation dose but in aqueous solution the activity declined more slowly at higher doses. The radiation dose to-produce 50% inactivation was 4 x 10/sup 7/ r in dry form and 6 x 10/sup 5/ r in solution, a 67-fold difference. The results suggest that diffusion of the free radicals (H: or OH:) produced in the primary process is considerably hindered at low temperature and by the absence of water. (H.H.D.)

• Research Organization: Max-Planck-Institut fur Biophysik, Frankfurt am Main
• NSA Number: NSA-16-020142
• OSTI ID: 4816947
• Journal Information: Arch. Hyg. u. Bakteriol., Journal Name: Arch. Hyg. u. Bakteriol. Vol. Vol: 145
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BACTERIA
BIOCHEMISTRY
BIOLOGY AND MEDICINE
CYTOCHROMES
ENZYMES
EXCITATION
IONIZATION
LIFETIME
NUCLEIC ACIDS
PLANTS
POLLEN
PROTEINS
QUANTITY RATIO
RADIATION DOSES
RADIATION EFFECTS
TEMPERATURE
WATER