X-ray-induced mutations in cultured human thyroid cells.
Cultured human thyroid cells were X-irradiated in vitro and assayed for resistance to 6-thioguanine. The average mutant frequency was 1.69 +/- 1.34 X 10(-5) (mean +/- SD) in controls, 3.74 +/- 2.21 X 10(-5) in cells exposed to 1 Gy, and 7.19 +/- 5.37 X 10(-5) in cells exposed to 2 Gy. The positive association between mutant frequency and dose was statistically significant. The estimated mutation induction rate was 2.54 +/- 0.71 X 10(-5) per gray, which is in close agreement with published results for human skin fibroblasts and mammary epithelial cells. These results extend and confirm earlier reports that mutation induction rates for fibroblasts and epithelial cells after exposure to X rays are similar.
Department of Radiobiology, Radiation Effects Research Foundation, Hiroshima, Japan.
N
N
Nakamura
R
R
Sposto
R C
RC
Miller
T
T
Hiraoka
N
N
Takeichi
D000328:Adult; D004351:Drug Resistance; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009154:Mutation; D013866:Thioguanine / Q000494:pharmacology; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects*
D013866:Thioguanine