Figure 6.

The β₂AR-dependent cAMP response, which is confined in control cells diffuses throughout the whole cytosol at different time points post-MI. (A) images of cardiomyocytes indicate areas of interest (coloured ovals) situated at various distances from the point of stimulation (white arrows) where FRET was measured after local selective stimulation of β₂ARs in T-Tubules; Scale bars in, 20 µM (B) colour-coded curves of FRET response corresponding to the four areas of interest as indicated on the right panels.(C) Differences of the relative β₂AR-cAMP levels at progressive distances from the point of original agonist application in comparison to control cardiomyocytes, N = 5/n = 1 each; N, number of animals; n, number of cells. ‘*’ indicates a significant difference in cAMP signal level from control, *P < 0.05 as determined by one-way ANOVA followed by Bonferroni post hoc correction.