[Internal and external sources of the radiation induce the blocking of the proliferation of the human endothelial cells in culture. G2-block is induced by beta-particle 3H-thymidine and gamma-rays 137Cs].
We found that low doses (0.12-0.46Gy) of (methyl-) 3H-thymidine incorporated into human endothelial cells induce the accumulation cells in G2-phase of the cell cycle. Temperate doses of (1-6 Gy) gamma-rays 137Cs were less effective in the G2-block estimated by flow cytometry analysis of DNA content. Furthermore, the induced the high level of the chromosome aberrations (bridges and fragments in anaphases). 1Gy of gamma-ray 137Cs and 0.005 Gy of beta-rays induced the same per cent of the aberrant anaphases. Apparently, that the damages of the cellular hereditary structures are responsible for the blocking of the cellular proliferation in G2-phase. We suggest, that the disposition 3H-thymidine into radiosensitive target (DNA) defines the high cytotoxic of the beta-rays.
Gil'iano
N Ia
NIa
Konevega
L V
LV
Stepanov
S I
SI
Semenova
E G
EG
Noskin
L A
LA
D001610:Beta Particles; D049109:Cell Proliferation / Q000528:radiation effects; D002588:Cesium Radioisotopes / Q000633:toxicity; D043171:Chromosomal Instability; D002869:Chromosome Aberrations; D004247:DNA / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects*; D004249:DNA Damage; D042783:Endothelial Cells / Q000528:radiation effects*; D016195:G2 Phase / Q000528:radiation effects*; D005720:Gamma Rays; D006801:Humans; D013936:Thymidine / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D014316:Tritium
D002588:Cesium Radioisotopes; D014316:Tritium; D004247:DNA; D013936:Thymidine