Uptake of pramipexole into hOCT2-HEK and mock cells. A, Pramipexole uptake was greater into hOCT1-MDCK cells than into mock cells. B, Apparent permeability of pramipexole versus concentration is plotted for pramipexole uptake into hOCT2-HEK cells and mock cells. Also plotted is the apparent permeability of TEA at 71.3 μM into hOCT2-HEK cells and mock cells. C, Inhibition of pramipexole uptake (5 μM) into hOCT2-HEK and mock cells by 10 μM corticosterone. ***, p < 0.001, compared with hOCT2-HEK cells not treated with corticosterone. Error bars denote SEM.