Mitochondrial chloride channels--What are they for?

This minireview focuses on observation of the properties, functional significance, and modulation of single chloride channels in the mitochondrial inner membrane using two electrophysiological methods--the patch-clamp and bilayer lipid membrane methods. Measurements of parameters such as conductance, Cl(-)/K(+) selectivity, voltage or pH dependence as well as their modulation by endogenous and exogenous compounds using individual mitochondrial chloride channels result in an unexpectedly wide range of values. This paper discusses the origin of this wide variety of channel parameters and the possible involvement of these channels in mitochondrial membrane potential oscillations, apoptosis, carrier function, and mitochondrial fusion and fission.