The movement of monocarboxylic acids across phospholipid membranes: evidence for an exchange diffusion between pyruvate and other monocarboxylate ions

Abstract

In the presence of monensin, the sodium salts of pyruvate, lactate, acetoacetate and β-hydroxybutyrate permeate in increasing order of effectiveness through liposomal membrans. This permeation is strongly pH dependent. Sodium pyruvate included in liposomes can be liberated into the medium by adding either monensin or other monocarboxylates. The latter process is a demonstration of an exchange diffusion of two compounds across a membrane without the help of a transport protein.