Figure 5.

Enhancement of [³H]-noradrenaline release from PC12 cell expressing P2Y₁ receptors by ADP. PC12 cell cultures were treated with pertussis toxin (PTX; 100 ng·mL⁻¹ for 24 h) or remained untreated, were labelled with [³H]-noradrenaline and superfused. Subsequent to a 60 min washout period, 4 min fractions of superfusate were collected. Tritium overflow was stimulated twice (S1 after 72 min and S2 after 92 min of superfusion) by 2 min exposures 25 mM KCl. ADP (10 µM) was applied as shown in Figure 1B. (A) The S2/S1 ratios of tritium overflow from non transfected (wild type; wt) PC12 cells in the absence (control) or presence of 10 µM ADP (n = 6). (B) The S2/S1 ratios of tritium overflow from PC12 cells expressing rat P2Y₁-GFP in the absence (control) or presence of 10 µM ADP (n = 6). P-values for the significance of differences between the results obtained in the absence and presence of ADP are indicated above the bars.