Stimulation of β-adrenoceptors increased protein kinase C (PKC) activation. (A) In the upper half, neonatal mouse cardiac fibroblasts (NMCFs) were treated with isoprenaline (ISO; 10 µM) for 5, 15 and 30 min, and cell lysates were immunoblotted with anti-phospho-PKC pan antibody or anti-PKC antibody as a reference control. In the lower half, summary data showing the fold increase of phospho-PKC/total PKC (p-PKC/PKC). *P < 0.05 vs. value at 0 min, n= 3. (B) The fold increase of PKC activity in these cell lysates. *P < 0.05 vs. value at 0 min, n= 3. (C) NMCFs were treated with isoprenaline (10 µM) for 5, 15 and 30 min, and cell lysates were separated into soluble or particulate fractions, then were immunoblotted with anti-PKC antibody, anti-caveolin-1 (Cav-1) or GAPDH antibody as reference control. In the lower half, mean ± SEM of data from three independent experiments.*P < 0.05 vs. value at 0 min, n= 3.