Effect of low dose rate radiation on cell growth kinetics.
Experimental determinations were made of cell number as a function of time for two strains of L5178Y mammalian cells maintained continuously in various environments of radiation. One strain possessed a shoulder in its dose response curve whereas the other did not. Neither strain showed any significant difference in growth rate for interdivision doses on the order of the median lethal dose or less delivered continuously at a low dose rate or pulsed every 4 h at a high instantaneous dose rate. It was also shown that large numbers of dead cells have little effect on growth rate and that these dead cells last as discrete entities for many days. A simple theory of growth rate in the presence of radiation is presented, and the agreement with the observations implies that there is no effect of any sublethal low dose rate radiation received in one generation on the growth rate or radiation sensitivity of the succeeding generation. Further analysis of the data also showed that for the no-shoulder cells at 37 degrees C, tritiated water had a relative biological effect close to unity for cell sterilization.
D000818:Animals; D002455:Cell Division / Q000528:radiation effects*; D002460:Cell Line; D004307:Dose-Response Relationship, Radiation; D007700:Kinetics; D007940:Leukemia L5178 / Q000503:physiopathology*; D007942:Leukemia, Experimental / Q000503:physiopathology*; D008433:Mathematics; D051379:Mice; D008954:Models, Biological
Nature. 1964 Aug 8;203:593-6
14250964
Nature. 1964 May 9;202:613-4
14195081
Int J Radiat Oncol Biol Phys. 1978 Nov-Dec;4(11-12):991-1000
569138
Int J Radiat Oncol Biol Phys. 1978 Jul-Aug;4(7-8):749-50
711546
Radiat Res. 1977 Feb;69(2):230-40
841001
Int J Radiat Biol Relat Stud Phys Chem Med. 1974 Oct;26(4):321-30
4548048
Radiat Res. 1974 Dec;60(3):453-72
10881723
Int J Radiat Biol Relat Stud Phys Chem Med. 1965;9(6):581-92
5295342
Int J Radiat Biol Relat Stud Phys Chem Med. 1976 Feb;29(2):197-200
1083384
Radiat Res. 1975 Sep;63(3):531-43
1162037
Radiat Res. 1969 Apr;38(1):186-203
5813476
Nature. 1965 Oct 9;208(5006):168-70
5884253
Int J Radiat Biol Relat Stud Phys Chem Med. 1966;11(4):339-47
5297655