Figure 8.

Effects of β‐adrenergic stimulation in HCN2‐Tg mice. A and B, HW/BW ratios (A) and blood pressures (B) in 24‐week‐old WT and HCN2‐Tg mice, with or without 1 week of isoproterenol (iso) administration (15 mg/kg per day; subcutaneous infusion): *P<0.05. (for HW/BW ratios, n=3 for WT without iso, n=5 for WT with iso, n=3 for Tg without iso, n=5 for Tg with iso; for blood pressure, n=3 in each group). Mice treated without iso are indicated as cont. Kruskal–Wallis nonparametric ANOVA followed by the Bonferroni correction was used for analysis among the 4 groups. NS, not significant. All data are shown as dot plots. C, Water consumption (g/day) in 24‐week‐old WT and Tg mice treated for 1 week with iso (15 mg/kg per day; subcutaneous infusion) (n=4 for WT mice, n=3 for Tg mice). The Mann–Whitney test was used for the analysis. NS, not significant. Data are shown as dot plots. D, Heart rate assessed by ambulatory electrocardiography in 24‐week‐old WT and HCN2‐Tg mice, with or without 1 week of isoproterenol (iso) administration (15 mg/kg per day; subcutaneous infusion): Kruskal–Wallis nonparametric ANOVA followed by the Bonferroni correction was used for analysis among the 4 groups. n=3 for each group. Data are shown as dot plots. HCN2‐Tg indicates hyperpolarization‐activated cyclic nucleotide‐gated channel 2 transgenic mice; WT, wild type; cont, control; HW/BW, heart weight‐to‐body weight ratios; ANOVA, analysis of variance.