NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblastsThe biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 micrometer2 and 0.09 to 5.56 x 10(-3) micrometer2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(-5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.
Document ID
20040089522
Acquisition Source
Johnson Space Center
Document Type
Reprint (Version printed in journal)
Authors
Chen, D. J.
(Los Alamos National Laboratory NM 87545, United States)
Tsuboi, K.
Nguyen, T.
Yang, T. C.
Date Acquired
August 21, 2013
Publication Date
October 1, 1994
Publication Information
Publication: Advances in space research : the official journal of the Committee on Space Research (COSPAR)
Volume: 14
Issue: 10
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
NASA Center JSC
NASA Discipline Number 04-10
NASA Discipline Radiation Health
NASA Program Radiation Health

Available Downloads

There are no available downloads for this record.
No Preview Available