Linked Life Data

4041062

Source:http://linkedlifedata.com/resource/pubmed/id/4041062

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1985-10-4
pubmed:abstractText
Exponentially growing eucaryotic cells, irradiated in interphase, are delayed in progression to mitosis chiefly by arrest in G2. The sensitivity of Chinese hamster ovary cells to G2-arrest induction by X rays increases through the cell cycle, up to the X-ray transition point (TP) in G2. This age response can be explained by cell cycle age-dependent changes in susceptibility of the target(s) for G2 arrest and/or by changes in capability for postirradiation recovery from G2-arrest damage. Discrimination between sensitivity changes and repair phenomena is possible only if the level of G2-arrest-causing damage sustained by a cell at the time of irradiation and the level ultimately expressed as arrest can be determined. The ability of caffeine to ameliorate radiation-induced G2 arrest, while inhibiting repair of G2-arrest-causing damage makes such an analysis possible. CHO cell monolayers were irradiated (1.5 Gy), then exposed to 5 mM caffeine for periods of 0-10 hr. Cell progression was monitored by the mitotic cell selection procedure. In the presence of caffeine, progression of irradiated cells was relatively unperturbed, but on caffeine removal, G2 arrest was expressed. The duration of G2 arrest was independent of the length of the prior caffeine exposure and, since cells of all ages were ultimately examined, the duration of arrest was also independent of cell cycle age at the time of irradiation. This finding indicates that the target for G2-arrest induction is present throughout the cell cycle and that the level of G2-arrest damage incurred is initially constant for all cell cycle phases. The data are consistent with the existence of a time-dependent recovery mechanism to explain the age dependence for radiation induction of G2 arrest.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0033-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
103
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
326-36
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Cell cycle age dependence for radiation-induced G2 arrest: evidence for time-dependent repair.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't