Abstract |
The induction of cytotoxicity, chromosomal aberrations, and sister chromatid exchanges (SCEs) was measured in CHO K-1c cells and in isogenic X-ray-sensitive mutant xrs-6c cells that had been irradiated with X rays and alpha particles in isoleucine-deficient alpha-minimal essential medium in G1 phase of the cell cycle. There was a noticeable shoulder region on the survival curve for CHO K-1c cells irradiated with very low doses of alpha particles, whereas this feature was absent for xrs-6c cells with alpha-particle doses as low as 0.5 cGy. Higher frequencies of chromatid-type aberrations were induced in G1-phase xrs-6c cells than in G1-phase CHO K-1c cells by both gamma- and alpha-particle irradiation. Induction of nonlethal chromosomal aberrations was observed following exposure to 2-6 cGy of alpha particles, doses yielding 97-100% cell survival. Irradiation with 0.5 cGy of alpha particles induced SCE; nearly 60% of irradiated cells contained significantly increased levels of SCE. However, only 3% of the nuclei of cells exposed to 0.5 cGy of alpha-particle radiation were actually traversed by an alpha particle. The observation that a large fraction of cells apparently survive exposure to very low doses of alpha-particle radiation with persistent genetic damage manifested by both chromosomal aberrations and SCEs may have important implications for the carcinogenic hazards of high-LET radiation.
|
Authors | H Nagasawa, J B Little, W C Inkret, S Carpenter, M R Raju, D J Chen, G F Strniste |
Journal | Radiation research
(Radiat Res)
Vol. 126
Issue 3
Pg. 280-8
(Jun 1991)
ISSN: 0033-7587 [Print] United States |
PMID | 2034785
(Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)
|
Topics |
- Alpha Particles
- Animals
- Cell Cycle
(radiation effects)
- Cell Line
- Cell Survival
(radiation effects)
- Chromosome Aberrations
- Chromosomes
(radiation effects)
- DNA Repair
- Dose-Response Relationship, Radiation
- Gamma Rays
- Mutation
- Radiation Tolerance
- Sister Chromatid Exchange
(radiation effects)
|