Does a transmembrane sodium gradient control membrane potential in mammalian mitochondria?

Abstract

In a recent publication, Hernansanz-Agusti̒n et al. propose that a sodium gradient across the inner mitochondrial membrane, generated by a Na⁺/H⁺ activity integral to Complex I can account for half of the mitochondrial membrane potential. This conflicts with conventional electrophysiological and chemiosmotic understanding.