Technical Report No. 20-88
X ray-induced mutations in cultured human thyroid cells
Nakamura N, Miller RC, Takeichi N, Sposto REditor’s note: A publication based on this report was published in Radiat Res 119:123-33, 1989.
Summary
Cultured human thyroid cells were X-irradiated in vitro and assayed for resistance to 6-thioguanine. The average mutant frequency was 1.69 plus or minus 1.34 x 10-5 (mean plus or minus SD) in controls, 3.74 plus or minus 2.21 x 10-5 in cells exposed at 1 Gy, and 7.19 plus or minus 5.37 x 10-5 in cells exposed at 2 Gy. The positive association between mutant frequency and dose was statistically significant. The estimated mutation induction rate was 2.54 plus or minus 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 confirm earlier reports that mutation induction rates for fibroblasts and epithelial cells after exposure to X rays are similar.
Cultured human thyroid cells were X-irradiated in vitro and assayed for resistance to 6-thioguanine. The average mutant frequency was 1.69 plus or minus 1.34 x 10-5 (mean plus or minus SD) in controls, 3.74 plus or minus 2.21 x 10-5 in cells exposed at 1 Gy, and 7.19 plus or minus 5.37 x 10-5 in cells exposed at 2 Gy. The positive association between mutant frequency and dose was statistically significant. The estimated mutation induction rate was 2.54 plus or minus 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 confirm earlier reports that mutation induction rates for fibroblasts and epithelial cells after exposure to X rays are similar.