Radiosensitivity of Young and Adult Subjects(1)

Vaglenov, A. (1,2) Carbonell, E. (2)

1National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria

2Grup de Mutagenesi, Unitat de Genetica, Departament de Genetica i de Microbiologia, Edifici Cn, Universitat Autonoma de Barcelona, Spain

(1)Corresponding author: Dr. Alexander Vaglenov, M.D., Ph.D.
Grup de Mutagenesi, Departament de Genetica i de Microbiologia,
Edifici Cn, Universitat Autonoma de Barcelona,
08193 Bellaterra, Cerdanyola del Valles, Spain.
Tel.: + 34 3 581 2597;
Fax: + 34 3 581 2387


Keywords:
Human lymphocyte micronucleus assay, age, gamma rays, radiosensitivity

Abbreviations:
CBMN = cytokinesis block micronucleus method
MN = micronuclei
MNs = spontaneous micronucleus frequencies
MNi = gamma ray-induced micronucleus frequencies

Abstract:
The radiosensitivity of 12 young persons (aged 7 to 17 years) and 17 adults (aged 60 to 82 years) belonging to a Bulgarian non-smoking population was investigated. For assessing radiosensitivity to the acute (0.77 Gy/min) gamma irradiation from 137Cs, the cytokinesis-block micronucleus method in peripheral blood lymphocytes was used.
    The mean spontaneous frequency of the micronuclei (mean±SD) in the young individuals is 14.75±5.56% and is significantly lower than the one obtained for the adults: 46.52±20.24% (p<0.0001). A linear increase of the micronuclei (MN) has been established with age: MN=8.36 + 0.55Y, r=0.715, p=0.001.
    Following an “in vitro” irradiation with 1 Gy gamma rays of 137Cs the mean frequency induced in the young persons amounted to 163.16±35.64% and is significantly higher than the one obtained for the adult: 125.06±18.74% (p<0.001). Radiosensitivity (determined after the differences between the micronucleus yields following irradiation (MNi) minus their corresponding spontaneous frequencies (MNs) diminishes in a linear mode with augmentation of age: MN=160.54–1.168Y, r = –0.718, p < 0.0001.
    The individual spontaneous, as well as the induced frequencies of the micronuclei varied in large scales. No correlation was found between the spontaneous MN yields and their corresponding frequencies induced after an “in vitro” gamma irradiation.
    Micronucleus frequencies grow in a linear fashion with ageing. The radiosensitivity of the young persons is significantly higher than that of the adults.


Received: 08 September 1998
Accepted: 17 November 1998

Posted: 3 April 1999

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