Effects of monoenergetic X-rays with resonance energy of bromine K-absorption edge on bromouracil-labelled E. coli cells.
In order to examine enhanced killing that might be induced by Auger cascades in the incorporated atoms in cells, bromouracil(BrU)-labelled E. coli cells were irradiated with monoenergetic X-rays at 13.49 and 12.40keV, just above and below the K-absorption edge of bromine. In both cases BrU-labelled cells were more sensitive for killing than were normal cells. However, when the degree of BrU-sensitization was compared between the two energies of X-rays, the enhanced killing at 13.49 keV was only small, 2 +/- 8 per cent based on the D0 value in saline. By the addition of DMSO, which is believed to suppress radical-mediated effects, killing of BrU-labelled cells was enhanced at 13.49 keV by 8 +/- 4 per cent as compared with 12.40 keV, based on D0. These results have been examined in terms of absorbed energy in BrU-labelled cells and in terms of the number of induced Auger events.
Maezawa
H
H
Department of Radiation Oncology, School of Medicine, Tokai University, Kanagawa, Japan.
Hieda
K
K
Kobayashi
K
K
Furusawa
Y
Y
Mori
T
T
Suzuki
K
K
Ito
T
T
D001976:Bromouracil / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D004926:Escherichia coli; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
D011838:Radiation-Sensitizing Agents; D001976:Bromouracil