Figure 9. Effects of substrate concentration, temperature and competitive inhibitor on Gly-Sar uptake by OECs.

A: OEC monolayers were incubated with various concentrations (0–5 mM) of Gly-Sar at 37°C (⧫) or 4°C (▴). Active (▪) uptake via PEPT1 was estimated according to the difference between 37°C and 4°C. B: The uptake of 0.5 mM Gly-Sar was measured in the absence or presence of increasing concentrations of methionine-glycine (0–5 mM). Uptake of Gly-Sar measured in the absence of the inhibitor dipeptide was set as 100%. N = 4.