Translocation of δPKC to mitochondria during cardiac reperfusion enhances superoxide anion production and induces loss in mitochondrial function

Eric N. Churchill, Luke I. Szweda

Research output: Contribution to journalArticle

61 Scopus citations


Activation of the δ-isoform of protein kinase C (δPKC) by certain conditions of oxidative stress results in translocation of the kinase to the mitochondria leading to release of cytochrome c and the induction of apoptosis. In the current study, the effects of myocardial reperfusion-induced δPKC translocation on mitochondrial function were assessed. Mitochondria isolated from hearts that had undergone ischemia (30 min) followed by reperfusion (15 min) exhibited a significant increase in the rate of superoxide anion (O2-.) generation. This was associated with the translocation of δPKC to the mitochondria within the first 5 min of reperfusion. δPKC translocation occurred exclusively during reperfusion and could be mimicked by infusion of intact hearts with H2O 2 suggesting redox-dependent activation during reperfusion. Infusion of a peptide inhibitor (δV1-1) specific to the δ-isoform of PKC significantly reduced reperfusion-induced increases in mitochondrial O2-. generation. Finally, the decline in mitochondrial respiratory activity evident upon prolonged reperfusion (120 min) was completely prevented by inhibition of δPKC translocation. Thus, δPKC represents a cytosolic redox-sensitive molecule that plays an important role in amplification of O2-. production and subsequent declines in mitochondrial function during reperfusion.

Original languageEnglish (US)
Pages (from-to)194-199
Number of pages6
JournalArchives of Biochemistry and Biophysics
Issue number2
StatePublished - Jul 15 2005



  • Free radical
  • Heart
  • Ischemia
  • Mitochondria
  • PKC
  • Reperfusion
  • Respiration

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

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