Figure 4.

Differences in regulation of cAMP dynamics by PDEs between pre-mature and mature murine transgenic brown adipocytes under β₃-AR activation. Representative FRET traces from cytosolic FRET sensor in pre-mature and mature BAs of β₃-AR activation selectively stimulated with CL 316,243 (50 μM in pre-mature BAs, 10 μM in mature BAs) followed by (A, D) PDE2 inhibitor BAY 60-7550 (BAY, 100 nM) (B, E) PDE3 inhibitor Cilostamide (Cilo, 10 μM) (C, F) PDE4 inhibitor Rolipram (Roli, 10 μM) with subsequent maximal FRET response achieved by inhibition of PDEs by 100 μM IBMX. (G) Quantification of FRET responses to individual family-selective (PDE 2, 3 or 4) inhibitors upon β₃-AR stimulation are shown as a percentage of the maximal PDE inhibition obtained using the unselective inhibitor IBMX. n = 4-8. Bar graphs represent ± S.E.M. Two-way ANOVA followed by Sidak's multiple comparison test was performed, significant differences correspond to ∗∗- p = 0.01.