A comparison of aberration distribution and cell-cycle progression in cells treated with bleomycin with those exposed to X-rays.
The extent of cell-cycle delay and the frequency of aberrant metaphases induced by bleomycin (BLM) and X-rays have been compared at doses which produce similar frequencies of chromosome aberrations by the 2 clastogenic agents (BLM, 40 micrograms/ml and X-rays, 2 Gy) in muntjac lymphocytes. The frequency of aberrant metaphases was low in BLM-treated cells; however, the number of aberrations per metaphase was higher than in cells exposed to X-rays. Thus in contrast to their uniform sensitivity to X-rays, the lymphocytes showed differential sensitivity to BLM. This might be due to differences among the cells in their uptake of BLM and/or its action on the nuclear membrane-DNA complex. In spite of the total number of chromosome aberrations being similar to that induced by X-rays, BLM did not induce a significant delay in cell-cycle progression as observed in the case of X-rays. A possible explanation could be that the DNA damages being limited to fewer cells than in the case of X-irradiation, the BLM-treated cultures had more normal cells allowing faster progression and/or unlike X-rays BLM may not be causing other cellular damages in addition to DNA breaks.
Chatterjee
A
A
Department of Zoology, Banaras Hindu University, Varanasi, India.
Raman
M J
MJ
D000818:Animals; D001761:Bleomycin / Q000633:toxicity*; D002453:Cell Cycle / Q000187:drug effects* / Q000528:radiation effects*; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D003670:Deer; D014965:X-Rays
D001761:Bleomycin