Fig. 1.

Pre-stimulation with CREB-activating transmitters reduces transmitter-induced calcium responses. a Schematic representation of the protocol used. b Activation of CREB-dependent transcription by different transmitters measured with a luciferase gene-reporting assay. Control is cells not treated with any transmitter but with vehicle; otherwise cells were stimulated with 100 µM ATP, 10 µM noradrenaline (NA), 10 nM endothelin-1 (ET-1), or 100 µM glutamate (Glu) and CREB activity measured after 6 h. Representative calcium traces (c, e, g) and quantification (d, f, h) of maximum increases after the addition of 100 µM ATP (c, d), 10 µM NA (e, f), or 10 nM ET-1 (g, h) after CREB activation with ATP, NA, ET-1, or Glu, identified with color codes. *P < 0.05, **P < 0.01, ***P < 0.001