Effect of irradiation on DNA synthetic period of the mitotic cycle in cells.
Kinetics of DNA synthesis in mitotic cycle of mouse corneal epithelial cells after single γ-irradiation (4 Gy) at the end of S period was studied by the method of radioautography. Normally, S period of corneal epithelial cells consists of several stages separated by intervals without DNA synthesis. The estimated mean duration of the first (S(1)) and second (S(2)) phases of S period was 16 and 10 h, respectively, and the interval between them was 7 h. Single irradiation at the end of S period changed the duration of mitotic cycle periods: S(2) phase became 2.2-longer than S(1) phase and the duration of g(1) period decreased, because the time for reparation in irradiated cell increases at the expense of g(1) period. Shortening of g(1) period is a factor promoting the appearance of transformed cells.
N. N. Blokhin Russian Cancer Research Center, Russian Academy of Medical Sciences, Moscow, Russia. shabalkin@km.ru
I P
IP
Shabalkin
E Yu
EY
Grigor'eva
M V
MV
Gudkova
A S
AS
Yagubov
D000818:Animals; D002453:Cell Cycle / Q000528:radiation effects*; D004247:DNA / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008938:Mitosis / Q000528:radiation effects*; D016196:S Phase / Q000528:radiation effects
D004247:DNA