Effect of steady-state activation of β-AR on cytosolic [cAMP] in RASMCs.

<p>Cytosolic cAMP measurements were conducted using the FRET-based cAMP sensor Epac1-camps in cultured RAMSCs cells incubated with cumulative increasing concentrations of isoproterenol (0.1 nM to 1 µM). <b><i>A</i></b>: Representative cAMP signals monitored in one cell. Pseudocolor images reflecting the CFP/YFP ratio were recorded at the times indicated by the letters on the graph. <b><i>B</i></b>: Concentration-response curve of isoproterenol effect as shown in <i>A</i>. Data are mean±SEM of 7 independent cells.