Induction of ion transport in rat heart mitochondria by fluorescamine

This report describes experimental results which show that the fluorescent reagent fluorescamine induces mitochondrial energy-independent swelling when the incubation media contain the chloride salts of the cations Li+, Na+, K+, Rb+, and Cs+. The reaction depends on the concentration of the dye and is inhibited by Mg2+, and its extension is closely related to the amount of the primary amino groups titrated by fluorescamine. Analysis of the labeled inner membrane in polyacrylamide gel shows that the amount of aminofluorescamine complex is lower when mitochondria are in the presence of Mg2+.