Effects of membrane H+ gradients on glucose analogue accumulation. MDCK cells were preloaded with glucose to establish outward facing glucose gradients. Accumulation of glucose tracer was then measured in the presence or absence of an inward directed H+ gradient as indicated (pH extracellular = 5.0; pH intracellular = 7.4), (pH extracellular = 5.0; pH intracellular = 5.0) (pH extracellular = 7.4; pH intracellular = 7.4). Triplicate accumulation time-points samples were measured. Mean and SD were calculated. A representative experiment is shown.