These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Alternative mechanisms for hydroperoxide-induced DNA single strand breakage. Author: Guidarelli A, Cattabeni F, Cantoni O. Journal: Free Radic Res; 1997 Jun; 26(6):537-47. PubMed ID: 9212348. Abstract: The results presented in this study point out the existence of similarities as well as differences in the DNA-damaging effects of organic vs. inorganic hydroper-oxides in human myeloid leukemia U937 cells. On the one hand, the formation of DNA single strand breaks (SSBs) induced by either hydrogen peroxide (H2O2) or tert-butylhydroperoxide (tBu-OOH) was prevented by iron chelators, was not affected by antioxidants or glucose omission before and during peroxide exposure and was enhanced by prior catalase depletion. Furthermore, H2O2- and tBu-OOH-induced DNA strand scission were also detected after treatment at 0 degree C. On the other hand, H2O2, but not tBu-OOH or cumene hydroperoxide (cum-OOH), produced DNA strand scission in isolated nuclei and post-lysed DNA samples. In addition, lowering the basal intracellular calcium concentration with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) markedly reduced the DNA-damaging efficiency of tBu-OOH while promoting only a slight decline in the number of DNA SSBs induced by H2O2. Taken together, these results are consistent with the commonly held theory that DNA damage caused by H2O2 is mediated by the formation of hydroxyl radicals. tBu-OOH-induced DNA single strand breakage appears to involve both the formation of H2O2 and a rise in cytosolic calcium ions.[Abstract] [Full Text] [Related] [New Search]