Comparison of F ratios generated from interphase and metaphase chromosome damage induced by high doses of low- and high-LET radiation

H. Wu, K. George, T. Kawata, V. Willingham, F. A. Cucinotta

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Although biophysical models predict a difference in the ratio of interchromosomal to intrachromosomal interarm exchanges (F ratio) for low- and high-LET radiations, few experimental data support this prediction. However, the F ratios in experiments to date have been generated using data on chromosome aberrations in samples collected at the first postirradiation mitosis, which may not be indicative of the aberrations formed in interphase after exposure to high-LET radiations. In the present study, we exposed human lymphocytes in vitro to 2 and 5 Gy of γ rays and 3 Gy of 1 GeV/nucleon iron ions (LET = 140 keV/μm), stimulated the cells to grow with phytohemagglutinin (PHA), and collected the condensed chromosomes after 48 h of incubation using both chemically induced premature chromosome condensation (PCC) and the conventional metaphase techniques. The PCC technique used here condenses chromosomes mostly in the G2 phase of the cell cycle. The F ratio was calculated using data on asymmetrical chromosome aberrations in both the PCC and metaphase samples. It was found that the F ratios were similar for the samples irradiated with low- and high-LET radiation and collected at metaphase. However, for irradiated samples assayed by PCC, the F ratio was found to be 8.2 ± 2.0 for 5 Gy γ rays and 5.2 ± 0.9 for 3 Gy iron ions. The distribution of the aberrations indicated that, in the PCC samples irradiated with iron ions, most of the centric rings occurred in spreads containing five or more asymmetrical aberrations. These heavily damaged cells, which were either less likely to reach mitosis or may reach mitosis at a later time, were responsible for the difference in the F ratios generated from interphase and metaphase analysis after exposure to iron ions.

Original languageEnglish
Pages (from-to)57-62
Number of pages6
JournalRadiation Research
Volume155
Issue number1
Publication statusPublished - 2001
Externally publishedYes

Fingerprint

Linear Energy Transfer
chromosomes
Interphase
Metaphase
metaphase
interphase
Chromosomes
Radiation
damage
dosage
mitosis
condensation
radiation
Iron
Mitosis
Ions
iron
ions
aberration
chromosome aberrations

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Radiology Nuclear Medicine and imaging
  • Biophysics
  • Radiation

Cite this

Comparison of F ratios generated from interphase and metaphase chromosome damage induced by high doses of low- and high-LET radiation. / Wu, H.; George, K.; Kawata, T.; Willingham, V.; Cucinotta, F. A.

In: Radiation Research, Vol. 155, No. 1, 2001, p. 57-62.

Research output: Contribution to journalArticle

Wu, H. ; George, K. ; Kawata, T. ; Willingham, V. ; Cucinotta, F. A. / Comparison of F ratios generated from interphase and metaphase chromosome damage induced by high doses of low- and high-LET radiation. In: Radiation Research. 2001 ; Vol. 155, No. 1. pp. 57-62.
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