Evidence for Similarities between Radiation Damage Expressed by β-araA and Damage Involved in the Interaction Effect Observed after Exposure of V79 Cells to Mixed Neutrons and γ Radiation

• Published in: Radiation research 1985-12, Vol.104 (3), p.303-316
• Main Authors: Iliakis, George, Frank Q. H. Ngo, Roberts, William K., Youngman, Kim
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Biological effects of radiation; Cell Line; Cell Survival - drug effects; Cell Survival - radiation effects; Cobalt Radioisotopes; Cricetinae; Cultured cells; DNA damage; Dosage; Dose-Response Relationship, Radiation; Fast Neutrons; Flasks; Fundamental and applied biological sciences. Psychology; Gamma Rays; Ionizing radiations; Irradiation; Neutrons; Radiation damage; Radiation dosage; Radiotherapy; Solar X rays; Tissues, organs and organisms biophysics; Vidarabine - pharmacology
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3576592

Plateau-phase V79 cells were exposed sequentially to fast neutrons and γ rays. A dose-dependent reduction in the shoulder width of the γ-ray survival curve was observed after preexposure of cells to neutrons. A similar effect was demonstrated on the neutron survival curve when cells were preirradiated with γ rays. Treatment of cells with 150 μM β-araA after either γ or neutron irradiation reduced primarily the shoulder of the survival curve. When β-araA was given to the cells after exposure to mixed radiation modalities, survival curves similar to those observed after exposure to a single radiation modality and treatment with β-araA were obtained. The kinetics of loss of the interaction observed after exposure of cells to γ rays following neutron irradiation was similar to the kinetics of loss of sensitivity to β-araA ($T_{1/2}=1\ {\rm h}$) measured by delaying drug administration after exposure to γ rays. The results suggest that the PLD expressed by β-araA is at least partly involved in the interactive effect observed after combined exposure of plateau-phase V79 cells to neutrons and γ rays.