Effect of hypertonicity and X radiation on DNA synthesis in normal and ataxia-telangiectasia cells

Journal Article · Wed Dec 01 04:00:00 EST 1982 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575927· OSTI ID:6380583

Painter, R B; Young, B R

Normal human cells and cells from patients with ataxia-telangiectasia (A-T) were exposed to culture medium made hypertonic by raising the NaCl concentration. The rate of DNA synthesis in both types of cells was depressed as a function of increasing hypertonicity. When cells of both types were exposed to X radiation and incubated in hypertonic medium, DNA synthesis appeared to be more radioresistant than in cells incubated in normal medium. Velocity sedimentation analysis showed that this was due to a hypertonicity-induced inhibition of replicon initiation, which is the same process affected by X radiation, indicating that the two treatments were not additive. After a 5-hr incubation in hypertonic medium, there was a new steady state of replicon initiation and elongation similar to that existing in cells grown in normal medium, except that fewer replicons were participating. At this time DNA synthesis in each type of cell had a characteristic response to radiation, i.e., radiosenstivie in normal cells and radioresistant in A-T cells. These results suggest that radioresistant DNA synthesis in A-T cells is not due to increased condensation of chromatin.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 6380583
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 92:3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOSYNTHESIS
DISEASES
DISPERSIONS
DNA
ELECTROMAGNETIC RADIATION
HYPERTONIC SOLUTIONS
IONIZING RADIATIONS
MIXTURES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PATIENTS
RADIATION EFFECTS
RADIATIONS
RADIOSENSITIVITY EFFECTS
SKIN DISEASES
SOLUTIONS
SYNTHESIS
TELANGIECTASIS
VASCULAR DISEASES
X RADIATION