テツ イオン オヨビ テツ サクタイ ニヨル DNAサ セツダン

P(論文)Ferric nitrilotriacetate (Fe^-NTA) is an iron complex. Repeated injections of Fe^-NTA in experimental animals induce iron overload and injuries of several organs. Fe^-NTA is also a potent carcinogen and has been shown to cause renal cell carinoma in the rat. In the present study, we investigated DNA strand breaks induced by Fe^-NTA in vitro by use of supercoiled closed circular DNA of plasmid pUC 19. The conformational change of DNA caused by a singel strand or double strand DNA break was easily detected by agarose gle electrophoresis. The DNA strand breaks were not observed with Fe^-NTA alone. However in the presence of 10mM hydrogen peroxide or 10mM dithiothreitol Fe^-NTA, at more than 10^M, caused DNA cleavage. Decrease of form I DNA and increase of form II and form III DNAs were observed by raising the Fe^-NTA concentration in the reaction. The requirement of hydrogen peroxide for the cleavage of DNA by Fe^-NTA suggested that Fe^-NTA catalyzed the production of hydroxyl radicals from hydrogen peroxide and the radicals caused the DNA strand breaks.departmental bulletin pape