(A) Uptake of Peramivir-(CH2)2-l-Val and Peramivir-l-Ile by MDCK-hPEPT1 cells. The MDCK-hPEPT1 cells were incubated with Peramivir-(CH2)2-l-Val or Peramivir-l-Ile (0.5 mM) for 10 min, pH 6.0, in the presence or absence of gly-sar (10 mM). After incubation, the concentration of Peramivir-(CH2)2-l-Val and Peramivir-l-Ile was determined by HPLC. *, P < 0.05, compared with the presence of gly-sar. (B) Concentration-dependent uptake of Peramivir-(CH2)2-l-Val and Peramivir-l-Ile in MDCK-hPEPT1 cells. Each value was calculated after subtracting the endogenous transporters contributions observed in the mock MDCK cells. Data are presented as mean ± SD, n = 3.