Alpha coefficient of dose-response for chromosome translocations measured by FISH in human lymphocytes exposed to chronic 60Co gamma rays at body temperature.
OBJECTIVE
To measure the alpha coefficient, the initial slope of the translocation dose-response curve, for 60Co gamma-rays in human lymphocytes.


METHODS
Human lymphocytes were exposed to 0, 0.32, 0.62 and 0.92 Gy of chronic 60Co gamma-rays under conditions that reduce the metabolic stress to the cells. Chromosome translocation frequencies were measured using fluorescence in situ hybridization with a whole-chromosome probe cocktail specific for chromosomes 1, 2, 4 (orange) and 3, 5, 6 (green).


RESULTS
A total of 72,383 metaphases were analysed (33,429 in exposed cells) in two individuals. The shape of the dose-response curves for translocations was linear, and alpha coefficient was measured as 0.024 +/- 0.002 translocations per cell per Gy for the combined data for two 24 year old male donors.


CONCLUSIONS
The alpha coefficients measured after chronic exposure were in good agreement with that reported in the literature for acute, low-dose exposure of human lymphocytes to 60Co gamma-rays.
Hsieh
W A
WA
Institute of Public Health, National Yang Ming University, Taipei, Taiwan.
Deng
W
W
Chang
W P
WP
Galvan
N
N
Owens
C L
CL
Morrison
D P
DP
Gale
K L
KL
Lucas
J N
JN
D000328:Adult; D000512:Alpha Particles; D001831:Body Temperature / Q000528:radiation effects*; D003037:Cobalt Radioisotopes; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D014178:Translocation, Genetic / Q000528:radiation effects*
D003037:Cobalt Radioisotopes