Cytochrome c release from brain mitochondria is independent of the mitochondrial permeability transition

FEBS Lett. 1998 Nov 20;439(3):373-6. doi: 10.1016/s0014-5793(98)01394-5.

Abstract

Ca2+ uptake by brain mitochondria induces the release of up to 40% of total cytochrome c in a cyclosporin A-insensitive manner. In the presence of ATP and Mg2+, this process is not accompanied by mitochondrial swelling. There is a moderate decrease in membrane potential under these conditions, but it is completely reversible upon removal of accumulated Ca2+ by addition of EGTA+A23187 but not by EGTA alone. These observations provide evidence that cytochrome c release from brain mitochondria does not require the membrane permeability transition. However, brain mitochondria can undergo the permeability transition in the absence of ATP and Mg2+, which results in cyclosporin A-sensitive large amplitude swelling, loss of Ca2+ uptake capacity and release of matrix solutes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Brain / cytology
  • Brain / metabolism*
  • Calcium / metabolism
  • Cell Membrane Permeability*
  • Cytochrome c Group / metabolism*
  • In Vitro Techniques
  • Magnesium / metabolism
  • Mitochondria / metabolism*
  • Rats

Substances

  • Cytochrome c Group
  • Adenosine Triphosphate
  • Magnesium
  • Calcium