Figure 3.

Effect of OCTN2-modifying pharmacophores on the uptake of [³H]-AC into human respiratory epithelial cell monolayers. Uptake of [³H]-AC into ATI-like (white columns), A549 (black columns), NCl-H441 (light grey columns), and Calu-3 (dark grey columns) epithelial cells was measured after 20 min at 37 °C and at pH 7.4 in the presence of (a) d-carnitine (500 µM) and (b) verapamil (200 µM). The results were obtained by calculating the difference between uptake at 37 °C and 4 °C. Data represent mean ± SEM (n = 3–6). ** p < 0.01; * p < 0.05 indicates a significant difference from the uptake at pH 7.4 (control). # p < 0.05 indicates a significant difference from data obtained in ATI-like monolayers.