Figure 8.
Functional significance of TRP channel block by 2-APB. (a) Phase-contrast images of HEK-293 cells (upper) or triple IP3R-knockout DT40 cells (lower) after 36–72 h incubation in vehicle (DMSO, Control), or vehicle plus 75 μM 2-APB (2-APB). Images are typical of at least five experiments. (b) De novo DNA synthesis indicated by bromodeoxyuridine (BRDU) incorporation detected by absorbance. BRDU incorporation was less after treatment with 2-APB (25 or 75 μM). The effect of 2-APB was significantly greater in Tet+ compared with Tet− cells (four independent experiments for each data point, 11–12 dishes of cells analysed in total). Gd3+ (10 μM) and 18-α-glycyrrhetinic acid (50 μM) were present to suppress background channel activity and stimulate TRPC5.