Na+-dependent, electroneutral L-ascorbate transport across brush border membrane vesicles from guinea pig small...

In brush border vesicles from guinea pig small intestine L-ascorbate transport is Na+-dependent and electroneutral (in the presence of Na+, as shown by its lack of response to either positive or negative delta psi across the membrane). L-Ascorbate transporter has the kinetic characteristics of a mobile carrier (Km for L-ascorbate, 0.3 mM). D-Isoascorbate (erythorbate) seems to be another, but poorer, substrate of the same transporter. L-Ascorbate transport is subjected to heterologous inhibition by D-glucose.