Low-dose hypersensitivity of V79 cells under exposure to gamma-rays and 4He ions of different energies: survival and chromosome aberrations.
OBJECTIVE
To examine the low-dose sensitivity of V79 cells under exposure to gamma-rays and 4He ions of different energies.


METHODS
Cell survival and cytogenetic analysis using the Giemsa technique were studied following irradiation to doses of 0-3 Gy at the INFN-LNL facilities.


RESULTS
Low-dose hyper-radiosensitivity (HRS) of V79 was demonstrated after irradiation with gamma-rays and alpha-particles of various linear energy transfers (LET) (58.9, 79.3 and 101.7 keV microm(-1)). Cytogenetic analysis showed an LET dependence of aberrations at a dose of 1Gy; the frequency of chromatid fragments appeared to vary with the number of alpha-particles traversing the cell nucleus. The results of both studies fit together to give a better understanding of so-called 'induced radioresistance' phenomenon.


CONCLUSIONS
The mechanism of induced cellular radioresistance appears to be initiated after a certain amount of energy is deposited in the cell nucleus. This amount depends on both radiation quality and the number of particles traversing the cell.
Tsoulou
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Institute of Nuclear Physics, NCSR Demokritos, Aghia Paraskevi 153 10, Athens, Greece. ktsoulou@mail.democritos.gr
Baggio
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L
Cherubini
R
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Kalfas
C A
CA
D000818:Animals; D002460:Cell Line / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D002869:Chromosome Aberrations; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006371:Helium / Q000494:pharmacology*
D006371:Helium