Base modification and strand breakage in isolated calf thymus DNA and in DNA from human skin epidermal keratinocytes exposed to peroxynitrite or 3- morpholinosydnonimine

Jeremy P E Spencer, Jon Wong, Andrew Jenner, Okezie I. Aruoma, Carroll E Cross, Barry Halliwell

Research output: Contribution to journalArticle

137 Scopus citations


Exposure of isolated calf thymus DNA and human skin epidermal keratinocytes to peroxynitrite or the peroxynitrite generator, 3- morpholinosydnonimine (SIN-1), led to extensive DNA base modification. Large increases in xanthine and hypoxanthine, possible deamination products of guanine and adenine, respectively, and in 8-nitroguanine were observed, but only small changes in some oxidized base products were seen. This pattern of damage suggests that hydroxyl radicals were not major contributors to base modification caused by peroxynitrite, as OH· is known to cause multiple oxidative modifications to all four DNA bases. Instead, it seems that reactive nitrogen species play a much greater role in the mechanism of base damage, producing both nitration and deamination of purine bases when DNA or whole cells are exposed to peroxynitrite. If this pattern of damage is unique to peroxynitrite, it might act as a marker of cellular damage by this species in vivo.

Original languageEnglish (US)
Pages (from-to)1152-1158
Number of pages7
JournalChemical Research in Toxicology
Issue number7
StatePublished - 1996


ASJC Scopus subject areas

  • Drug Discovery
  • Organic Chemistry
  • Chemistry(all)
  • Toxicology
  • Health, Toxicology and Mutagenesis

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