Journal of Bioenergetics and Biomembranes

, Volume 28, Issue 2, pp 131–138

The permeability transition pore as a mitochondrial calcium release channel: A critical appraisal

  • Paolo Bernardi
  • Valeria Petronilli

DOI: 10.1007/BF02110643

Cite this article as:
Bernardi, P. & Petronilli, V. J Bioenerg Biomembr (1996) 28: 131. doi:10.1007/BF02110643


Mitochondria from a variety of sources possess an inner membrane channel, the permeability transition pore. The pore is a voltage-dependent channel, activated by matrix Ca2+ and inhibited by matrix H+, which can be blocked by cyclosporin A, presumably after binding to mitochondrial cyclophilin. The physiological function of the permeability transition pore remains unknown. Here we evaluate its potential role as a fast Ca2+ release channel involved in mitochondrial and cellular Ca2+ homeostasis. We (i) discuss the theoretical and experimental reasons why mitochondria need a fast, inducible Ca2+ release channel; (ii) analyze the striking analogies between the mitochondrial permeability transition pore and the sarcoplasmic reticulum ryanodine receptor-Ca2+ release channel; (iii) argue that the permeability transition pore can act as a selective release channel for Ca2+ despite its apparent lack of selectivity for the transported speciesin vitro; and (iv) discuss the importance of mitochondria in cellular Ca2+ homeostasis, and how disruption of this function could impinge upon cell viability, particularly under conditions of oxidative stress.

Key words

Mitochondrial channels permeability transition pore calcium channels cyclosporin A ryanodine receptor 

Copyright information

© Plenum Publishing Corporation 1996

Authors and Affiliations

  • Paolo Bernardi
    • 1
  • Valeria Petronilli
    • 1
  1. 1.CNR Unit for the Study of Biomembranes and the Laboratory of Biophysics and Membrane Biology, Department of Biomedical SciencesUniversity of PadovaItaly