Fig. 3.

Effect of HgCl₂ (A) or MTS reagents (B) on transport activity of hOAT1 and hOAT3. Whereas a range of HgCl₂ concentrations were tested (0–1,000 μM), the MTS reagents {N-biotinylaminoethyl methanethiosulfonate-biotin (MTSEA-B), MTSEA, [2-(trimethylammonium)ethyl] methanethiosulfonate bromide (MTSET), and sodium (2-sulfonatoethyl)methanethiosulfonate (MTSES)} were used at a final concentration of 1 mM. Uptake experiments were also conducted in the presence or absence of a saturating concentration (1 mM) of either unlabeled PAH or ES (no HgCl₂ or MTS reagents present). Values are means ± SE of 3–6 separate experiments. *Significantly different from control (no inhibitor present), P < 0.05, Student's t-test.