Fig. 4
Extra- and intra-cellular pH dependence of [3H]p-TA uptake by TR-CSFB3 cells. a [3H]p-TA uptake (0.15 μCi/well) at pH 6.0, pH 7.4, and pH 8.4 was tested at 37 °C for 2 min. Each column represents the mean ± S.E.M. (n = 3). **p < 0.01, significant difference between the groups. b TR-CSFB3 cells were preincubated with buffer A at pH 7.4 or pH 8.4 in the absence (untreated and acute) or presence (pretreated) of 30 mM ammonium chloride for 20 min. After removal of the buffer, the cells were incubated with [3H]p-TA (0.15 μCi/well) at pH 7.4 or pH 8.4 in the absence (untreated and pretreated) or presence (acute) of 30 mM ammonium chloride at 37 °C for 2 min. Each column represents the mean ± SEM (n = 3–6). *p < 0.05 and **p < 0.01, significant difference between the groups