Radiation response of E. coli after combined treatment with misonidazole and WR-2721 at various oxygen concentrations.
It has been reported that the aminothiol compound WR-2721 is a promising radioprotective agent and in combination with misonidazole (MISO) seems to be of therapeutic benefit. Since the radiomodification is oxygen-dependent, the actual oxygen status of cells and the surrounding media is an important factor influencing their effectiveness. Escherichia coli B/r radioresponse was studied either alone or in combination with these compounds at various oxygen concentrations ranging from anoxia to high oxygen content. WR-2721 had a protective effect under anoxic conditions and gave overall protection when oxygen was present. The maximum protection was seen at 3.2% O2 in N2 (PF 2.08). In combination with MISO the hypoxic sensitization of MISO was completely abolished by WR-2721, resulting in radioprotection under hypoxic conditions as well. Under euoxic conditions MISO was able to reduce the protective effect of WR-2721 by about 21%. According to our results MISO and WR-2721 influence each other in their radiomodifying effect in either fixation or repair of the radiation-induced damage.
Dám
A M
AM
Frederic Joliot-Curie National Research Institute for Radiobiology and Radio-Hygiene, Budapest, Hungary.
Gazsó
L G
LG
Bodó
K
K
D004999:Amifostine / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000378:metabolism / Q000528:radiation effects*; D008920:Misonidazole / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D011836:Radiation Tolerance / Q000187:drug effects*; D011853:Radiobiology
D008920:Misonidazole; D004999:Amifostine; D010100:Oxygen