Effect of X irradiation on the progression of mouse 10T1/2 cells released from density-inhibited cultures

Journal Article · Thu Mar 01 04:00:00 EST 1984 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576145· OSTI ID:7133592

Nagasawa, H ^[1]; Robertson, J B; Arundel, C S; Little, J B

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1. Harvard School of Public Health, Boston, MA

When mouse C3H 10T1/2 cells were allowed to reach the density-inhibited plateau phase of growth, 0-3% of the cells were in the S phase as determined by pulse-labeling indices and about 90% of cells were in the G/sub 1/ phase as determined by flow microfluorometry (FMF). Density-inhibited cultures were exposed to moderate doses of X ray; immediately after X irradiation the cultures were trypsinized and the cells were subcultured at low density in fresh medium. FMF profiles and pulse and continuous-labeling indices were studied. It was determined by pulse-labeling indices that the cell population which was released from the plateau-phase cultures remained in the G/sub 1/ phase longer than the duration of the normal G/sub 1/ phase in exponentially growing cells. When plateau-phase cultures were irradiated with 400 rad before subculture, the cells moved into the S phase approximately 4 hr later than did nonirradiated cells. Despite the G/sub 1//S delay, both irradiated and nonirradiated cell populations showed a similar rate of progression through the S phase. As determined by cumulative labeling indices, the fraction of cells which remained in G/sub 1/ up to 120 hr post-subculture (G/sub 1/ block) increased linearly with X-ray doses. There was no measurable X-ray-induced G/sub 1/ delay or G/sub 1/ block in cells irradiated after subculture at the G/sub 1//S border during semi-synchronous growth.

• OSTI ID: 7133592
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 97:3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

550300 -- Cytology
560121* -- Radiation Effects on Cells-- External Source-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CELL CYCLE
CELL FLOW SYSTEMS
CONNECTIVE TISSUE CELLS
ELECTROMAGNETIC RADIATION
FIBROBLASTS
IONIZING RADIATIONS
MAMMALS
MICE
MITOTIC DELAY
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RODENTS
SOMATIC CELLS
VERTEBRATES
X RADIATION