Fig. 3.

Isoproterenol-stimulated Ca²⁺/calmodulin-dependent kinase II (CaMKII; A) and phospholamban (PLB; B) activity in mice (n = 4 for each group). A: representative immunoblot showing accumulation of phospho-CaMKII after treatment with 10 μg·g⁻¹·min⁻¹ isoproterenol infusion in WT and β₂ARKO mice. Summary graph represents a significant increase of phospho-CaMKII in WT and β₂ARKO mice. B: representative immunoblot showing accumulation of phospho-PLB after treatment with 10 μg·g⁻¹·min⁻¹ isoproterenol infusion in WT and β₂ARKO mice. Summary graph represents a significant increase of Ser-16 (left) and Thr-17 (right) in WT and β₂ARKO mice. *P < 0.005, treatment with isoproterenol vs. without isoproterenol for each group.