HFD impairs adrenergic reserve, and induces diastolic and systolic dysfunction in murine hearts. a and b) HFD leads to reduced cAMP and PKA phosphorylation at serine 16 of PLB and at serine 23/24 of troponin I (TnI) in mouse hearts. HFD also leads to reduced serca expression (n=12). *p < 0.05 and **p < 0.01by Student's t-test c) HFD promotes time-dependent systolic and diastolic dysfunction in mouse hearts (n=12). &&p < 0.01, &&&p < 0.001 by repeated measures ANOVA. d and e) After 6 month of HFD, mouse hearts display reduced PKA phosphorylation of PLB (S16, n=6) and contractile response to β adrenergic stimulation (ISO, 0.2 mg/kg in vivo, n=12). ** p < 0.01, and *** p < 0.001 by one-way ANOVA followed by post hoc Tukey's test.