Detection of Auger enhancement induced in HeLa cells labeled with iododeoxyuridine and irradiated with 150 kV x-rays--Effects of cysteamine and dimethylsulfoxide.
We examined the effects of cysteamine and dimethylsulfoxide on the lethality of iododeoxyuridine-labeled HeLa cells irradiated with 150 kV x-rays (effective energy was 48 keV) and compared with those irradiated with 60Co gamma-rays. The protectable fraction was estimated from the regression lines for the reciprocal plots of the concentration of protectors, versus the degree of protection. The protectable fraction by cysteamine was 9.4% lower in iododeoxyuridine-labeled cells than in control cells when they were irradiated with x-rays, whereas no such difference was observed with dimethylsulfoxide. The slopes of the regression lines were steeper (i.e., more difficult to protect) for both protectors in iododeoxyuridine-labeled cells irradiated with x-rays. No such differences were observed in gamma-irradiated cells. The cause for these differences are attributable to Auger enhancement. The results suggest that at least a portion of Auger enhancement is not protectable by cysteamine and is hard to be protected by both protectors cysteamine and dimethylsulfoxide.
Shinohara
K
K
Department of Radiation Research, Tokyo Metropolitan Institute of Medical Science, Bunkyo-ku, Japan. shinohara@rinshoken.or.jp
Nakano
H
H
Ohara
H
H
D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003037:Cobalt Radioisotopes / Q000494:pharmacology; D003543:Cysteamine / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D006367:HeLa Cells / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D007065:Idoxuridine / Q000494:pharmacology; D018499:Linear Energy Transfer; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D014965:X-Rays
D003037:Cobalt Radioisotopes; D011837:Radiation-Protective Agents; D003543:Cysteamine; D007065:Idoxuridine; D004121:Dimethyl Sulfoxide