Chromatin decondensed by acetylation shows an elevated radiation response

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3577324· OSTI ID:6171700

Nackerdien, Z; Michie, J; Boehm, L

V-79 Chinese hamster lung fibroblasts exposed to 5 mM n-sodium butyrate were irradiated with 60Co gamma rays and cell survival was determined by the cell colony assay. In a separate set of experiments the acetylated chromatin obtained from these cells was irradiated and the change of molecular weight of the DNA was evaluated by alkaline sucrose density centrifugation. At a survival level of 10(-2) to 10(-4) cells exposed to butyrate were found to be 1.3-1.4 times more radiosensitive than control cells. Exposure of isolated chromatin to 100 Gy of 60Co gamma irradiation generated 0.9 +/- 0.03 single-strand breaks (ssb) per 10 Gy per 10(8) Da and 2.0 +/- 0.3 ssb/10 Gy/10(8) Da for control and acetylated chromatin, respectively. The elevated radiation sensitivity of chromatin relaxed by acetylation is in good agreement with previous results on chromatin expanded by histone H1 depletion. Packing and accessibility of DNA in chromatin appear to be major factors which influence the radiation sensitivity. The intrinsic radiation sensitivity of chromatin in various packing states is discussed in light of the variation of radiation sensitivity of whole cells in the cell cycle which incorporates repair.

• Research Organization: Univ. of Stellenbosch, Tygerberg (South Africa)
• OSTI ID: 6171700
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 117:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACETYLATION
ACYLATION
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
BUTYRIC ACID
CARBOXYLIC ACIDS
CENTRIFUGATION
CHEMICAL REACTIONS
CHROMATIN
COBALT 60
COBALT ISOTOPES
CONNECTIVE TISSUE CELLS
DNA
ELECTROMAGNETIC RADIATION
FIBROBLASTS
GAMMA RADIATION
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
HAMSTERS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LUNGS
MAMMALS
MINUTES LIVING RADIOISOTOPES
MOLECULAR WEIGHT
MONOCARBOXYLIC ACIDS
NUCLEI
NUCLEIC ACIDS
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOISOTOPES
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RESPIRATORY SYSTEM
RODENTS
SEPARATION PROCESSES
SOMATIC CELLS
STRAND BREAKS
SURVIVAL TIME
ULTRACENTRIFUGATION
VERTEBRATES
YEARS LIVING RADIOISOTOPES