Fig. 4.

Bar graphs representing the effects of a KCl-induced depolarization on the human aromatase activity expressed by HEK293 intact cells (A), aromatase protein concentration as determined by Western blot on these cells (B), and blocking of KCl-induced reduction of aromatase activity by kinase inhibitors (C). A, Cells were submitted to two successive preincubation treatments (1 and 2) and aromatase was assayed at the end of each preincubation. The duration of preincubations varied from experiment to experiment and is indicated in the corresponding bars. Four groups of experiments were performed in which cells were incubated in sequence in DMEM followed by DMEM (a1–a2), DMEM + 100 mm KCl followed by DMEM (b1–b2 and d1–d2), or DMEM followed by DMEM + 100 mm KCl (c1–c2). *, P < 0.05 vs. matched control conditions. B, Bar graph representing the aromatase protein concentration expressed as the ratio of the mean OD of the aromatase to the mean OD of actin. Proteins were collected after the last assay in each of the four experiments described in A (a2, b2, c2, and d2). The shading of the bars corresponds to the shading in part A of the figure (DMEM, white; DMEM + KCl, black; DMEM after DMEM + KCl, hatched; values are presented as mean ± sem, five independent replicates). C, Bar graph representing the inhibition of aromatase activity by KCl, whereas the addition of 1 μm staurosporine or 50 μm genistein blocked the effect of KCl-induced depolarizations on AA. *, P < 0.05 vs. no KCl condition, same treatment; ***, P < 0.001 vs. no KCl, same treatment.