Left ventricular (LV) +(dP/dt)max (A-C),
-(dP/dt)max (D-F) and heart rate (G-I) recorded in WT (A,
D, G), AC5KO (B, E, H) and AC6KO (C, F, I) mice treated first with
timolol (2.5 mg/kg i.p.) followed by combined PDE3 inhibitor cilostamide
(3 mg/kg i.p.) and PDE4 inhibitor rolipram (10 mg/kg i.p.). To verify
continuous and complete βAR blockade, timolol (2.5 mg/kg i.p.) was
administered a second time after the PDE inhibitors. All mice received
either saline or PTX injection i.p. three days prior to study.
Experiments were conducted after vagotomy. Data are mean±SEM.
*P<0.05, two-way repeated measures ANOVA with Tukey’s multiple
comparisons test; **P<0.05, two-way ANOVA with Sidak’s multiple
comparisons test; #P<0.05 PTX-treated AC6KO vs. PTX-treated WT and
AC5KO, two-way ANOVA with Sidak’s multiple comparisons test. ##P<0.05
vs. baseline, Cil/Rol and the second timolol in respective saline and
PTX treated groups, two-way repeated measures ANOVA with Tukey’s
multiple comparisons test.