Fig. 3.

Effect of uptake time (5 s–30 min) on OSTα/β-mediated TCA and estrone sulfate (E₁S) transport. OSTab and Mock cells were incubated with [³H]TCA or [³H]E₁S (300 nCi/ml, 20 µM) in ECF Na− buffer (pH 7.4) at 37°C for 0–30 min. Background levels derived from Mock cells were subtracted, and uptake measurements were normalized to total cell protein. Values are means ± SD from 3 independent experiments.