Chromatid damage induced by 238Pu alpha-particles in G2 and S phase Chinese hamster V79 cells.
The comparative induction of chromatid aberrations by 238Pu alpha-particles, or by 250 kVp X-rays was investigated in V79 Chinese hamster cells. Metaphases were sampled at hourly intervals postirradiation up to 8 h and BrdU/FPG staining methods were used to distinguish G2, S and G1 phase cells. Two experiments were performed. In the first, an alpha-particle dose of 0.41 Gy was compared with an X-ray dose of 1.5 Gy used in a previously published study. In the second, an X-ray dose of 1.2 Gy was used in parallel with 0.41 Gy of alpha-particles to produce a similar overall frequency of interchanges, and allow comparative ratios to be derived for other aberration types. At these isoexchange doses, alpha-particles produce relatively less gaps and breaks, particularly in late G2, and significantly more isochromatid deletions. A very high proportion of the isochromatid deletions were incomplete after alpha-particles compared with X-rays, but no difference in incompleteness was found for interchanges. With X-rays, about 6% of interchanges are complex intra-interchange forms. At similar exchange frequencies this increases to 26.7% for alpha-irradiation, suggesting increased multiple lesion interaction. Differences in dose distribution between alpha-particles and X-rays are discussed and mitotic delay is examined after separation of the analysed cells into damaged and undamaged classes.
Griffin
C S
CS
MRC Radiobiology Unit, Chilton, Didcot, UK.
Harvey
A N
AN
Savage
J R
JR
D000512:Alpha Particles; D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002460:Cell Line; D002842:Chromatids / Q000187:drug effects / Q000528:radiation effects*; D002872:Chromosome Deletion; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D016195:G2 Phase / Q000528:radiation effects; D008938:Mitosis / Q000528:radiation effects; D011005:Plutonium / Q000494:pharmacology*; D016196:S Phase / Q000528:radiation effects; D012854:Sister Chromatid Exchange; D014965:X-Rays
D011005:Plutonium; D001973:Bromodeoxyuridine