Effect of dimethylthiourea on chromium (VI)-induced DNA single-strand breaks in Chinese hamster V-79 cells.
The effect of 1,3-dimethyl-2-thiourea (DMTU), a specific hydroxyl radical scavenger on chromate-induced DNA breaks, was studied using Chinese hamster V-79 cells. Incubation of cells with Na2CrO4 plus DMTU resulted in a small but significant decrease in cellular levels of the metal-caused DNA single-strand breaks. Electron spin resonance studies showed that DMTU did not affect the formation of chromium (V) complexes either in cells or in the reaction of Na2CrO4 with reduced glutathione in vitro, however, DMTU suppressed the generation of hydroxyl radicals in the reaction of hydrogen peroxide and chromium (V) in vitro. Thus, Na2CrO4-induced DNA breaks were inhibited by DMTU, possibly due to its ability to scavenge hydroxyl radicals. These and other previous studies indicated that the formation of hydroxyl radicals contribute to the induction of DNA breaks by Na2CrO4 in intact cells, but presumably is not the only mechanism involved.
Ueno
S
S
Department of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Aomori, Japan.
Sugiyama
M
M
Susa
N
N
Furukawa
Y
Y
D000818:Animals; D002478:Cells, Cultured; D002840:Chromates / Q000494:pharmacology*; D006224:Cricetinae; D004249:DNA Damage; D004347:Drug Interactions; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000494:pharmacology*; D017665:Hydroxyl Radical / Q000737:chemistry; D010084:Oxidation-Reduction; D013890:Thiourea / Q000031:analogs & derivatives* / Q000494:pharmacology
D002840:Chromates; D016166:Free Radical Scavengers; D017665:Hydroxyl Radical; C038983:1,3-dimethylthiourea; D013890:Thiourea