Cultured mouse SR-1 cells exposed to low dose of gamma-rays become less susceptible to the induction of mutagenesis by radiation as well as bleomycin.
The effect of pre-exposure of cultured mouse SR-1 cells to a low dose of gamma-rays on the induction of mutations at the hprt locus by subsequent high dose radiation or bleomycin was studied. When cells were pre-exposed to 0.01 Gy gamma-rays, the induction of mutations by a 3 Gy gamma-ray dose given 18 or 24 h later was significantly reduced as compared with those which did not receive the low dose pre-exposure. When cells were challenged with 5 or 10 micrograms/ml bleomycin for 12 h, which can produce double-strand breaks in DNA, instead of 3 Gy gamma-rays, a similar mutagenetic adaptive response was observed. We conclude that this resistance to radiation- or bleomycin-induced mutation is attributed to the induction of a DNA double-strand break repair mechanism.
Zhou
P K
PK
Department of Biochemistry, Institute of Radiation Medicine, Beijing, PRC.
Liu
X Y
XY
Sun
W Z
WZ
Zhang
Y P
YP
Wei
K
K
D000818:Animals; D001761:Bleomycin / Q000494:pharmacology*; D003037:Cobalt Radioisotopes; D004351:Drug Resistance / Q000528:radiation effects; D005720:Gamma Rays; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D008325:Mammary Neoplasms, Experimental; D051379:Mice; D016296:Mutagenesis / Q000187:drug effects* / Q000528:radiation effects*; D011836:Radiation Tolerance / Q000187:drug effects; D014407:Tumor Cells, Cultured
D003037:Cobalt Radioisotopes; D001761:Bleomycin; D007041:Hypoxanthine Phosphoribosyltransferase