• adenine nucleotide translocase;
  • calcium;
  • cardiolipin;
  • membrane potential;
  • oxidative stress;
  • permeability transition


When mitochondria are subjected to oxidative stress and relatively high [Ca2+], they undergo a ‘permeability transition’ in which the inner membrane becomes freely permeable to low-molecular-weight solutes. This phenomenon reflects reversible deformation of the adenine nucleotide translocase, the loss of its native gating properties and the stabilization of the deformed state by cyclophilin-D. The permeability transition may be a factor in cell dysfunction associated with aging. This can manifest in a number of ways ranging, in the most severe, from impaired energy transduction and compromised viability to more subtle influences on the propagation of Ca2+ signals. This article critically examines data relevant to this issue.