Cytochrome c release from mitochondria to the cytosol was suppressed in the ischemia-tolerance-induced hippocampal CA1 region after 5-min forebrain ischemia in gerbils

Neurosci Lett. 2000 Jan 7;278(1-2):53-6. doi: 10.1016/s0304-3940(99)00894-0.

Abstract

Cytochrome c was detected by immunoblotting in the cytosolic fraction 3 h after 5-min ischemia in the non-ischemia-tolerant CA1 region in which about 96% of neurons had developed delayed neuronal death, while less cytosolic cytochrome c was detected in the ischemia-tolerance-induced CA1 region where many more neurons survived. In the immunohistochemical study using anti-non-native cytochrome c monoclonal antibody, immunoreactivity was observed throughout the cytoplasm in the non-ischemia-tolerant CA1 neurons, but not in the normal and ischemia-tolerant CA1 neurons. Then we determined whether Bcl-2, Bax, Bcl-xL and Bcl-xS, which regulate the release of cytochrome c from mitochondria, were altered in the ischemia-tolerant CA1 region. Bcl-2 and Bax were up-regulated in the ischemia-tolerant group, but Bcl-xL and Bcl-xS showed no apparent difference in their expression. These results suggest that cytochrome c release is prevented in CA1 neurons in gerbils in which ischemia-tolerance had been induced and that the altered ratio of Bcl-2 to Bax may play a part in this mechanism.

MeSH terms

  • Animals
  • Brain Ischemia / metabolism*
  • Cytochrome c Group / metabolism*
  • Cytosol / metabolism
  • Gerbillinae
  • Hippocampus / metabolism*
  • Hippocampus / ultrastructure
  • Ischemic Preconditioning*
  • Male
  • Mitochondria / metabolism*
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / metabolism*
  • Prosencephalon / blood supply*
  • Proto-Oncogene Proteins / biosynthesis
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis
  • Pyramidal Cells / metabolism
  • Pyramidal Cells / ultrastructure
  • bcl-2-Associated X Protein
  • bcl-X Protein

Substances

  • Cytochrome c Group
  • Nerve Tissue Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • bcl-2-Associated X Protein
  • bcl-X Protein