PERSPECTIVES ON THE MITOCHONDRIAL PERMEABILITY TRANSITION

The permeability transition, a sudden permeability increase of the inn er mitochondrial membrane that is greatly favored by Ca2+ accumulation , has puzzled mitochondrial scientists for more than 40 years. It is n ow recognized that this phenomenon is mediated by opening a high condu ctance channel (the mitochondrial permeability transition pore) whose open-closed transitions are highly regulated. Through the pore mitocho ndria may participate in intracellular signalling, and release protein s involved in amplification of the cell death cascade triggered by a v ariety of physiological and pathological stimuli. Yet, the basic quest ions of the molecular nature of the permeability transition pore, its physiological role and its very occurrence in vivo remain a matter of intense debate. This short review is meant to summarize our current vi ews on the mitochondrial permeability transition, its perspectives, an d our strategies to resolve at least some of the outstanding issues ab out its nature and function. (C) 1998 Elsevier Science B.V.