Inhibition of [3H]taurine uptake by unlabeled taurine in the absence and presence of GES.
HEK293 cells (1*105 cells/well) stably expressing the F. hepatica (A, B) or the human taurine transporter (C, D) were incubated for 10 min in the presence of 0.1 μM [3H]taurine and of the indicated concentrations of unlabeled taurine and of GES. Data represent means ± S.D. from three independent experiments carried out in duplicate. The solid lines in panels A and C were drawn by fitting the data to a monophasic inhibition curve. In panels, B and D, the data shown in panels A and C, respectively, were replotted in Dixon plots to visualize the non-competitive and the competitive inhibitory action of GES by the intersecting lines (B) and the parallel lines (D), respectively.