AKT1 and cardiac hypertrophy: To further investigate the differences in the effect of ISO on cardiac remodeling between WT and Rgs2/5 dbKO mice, we examined the cardiac expression and phosphorylation of protein kinase B (AKT) and extracellular signal‐regulated kinase (ERK) which are, respectively, associated with physiologic and pathologic cardiac hypertrophy and both of which are downstream effectors of Gi/o signlaing (Anger et al., 2007; Proud, 2004; Yart et al., 2002).