Fig. 3.
Rate of cAMP decay at the plasma membrane of wild-type and PDE4BKO myocytes. (A) Wild-type and PDE4BKO myocytes expressing Epac2-PM were stimulated for the indicated times with Iso (10 nM) followed 80 s later by treatment with propranolol (1 µM). At the end of the incubation IBMX (100 µM) plus Fsk (50 µM) was added to measure the maximal response of the cell. The average ratio R/R0 (R = CFP/FRET) is reported and the number of cells analyzed (n) includes data from three or more experiments. Data were analyzed using a two-way ANOVA. (B,C) Data were fitted with an exponential decay equation (B) and the average t1/2 off was calculated for the two genotypes (C). Data were analyzed using an unpaired Student's t-test; *P<0.05. The number of cells analyzed (n) includes data from at least three experiments. Error bars correspond to the s.e.m. Fsk, forskolin.