Figure 3.

C1C2 Expression Prevents Deleterious Effects of Continuous Isoproterenol Infusion on LV Function

(A, B) In Con, 7 days of continuous Iso infusion tended to reduce LV peak +dP/dt (A) and LV peak −dP/dt (B). In contrast, in C1C2 mice, 7 days of Iso infusion increased LV peak +dP/dt (p = 0.026) (A) and peak −dP/dt (p = 0.006) (B). No between-group differences were seen in pre-Iso LV +dP/dt (p = 0.22) or LV −dP/dt (p = 0.27). (C) Similarly, continuous Iso infusion was associated with reduced LV developed pressure in Con mice (p = 0.012) but with increased LV developed pressure in C1C2 mice (p = 0.016). (D) Heart rate showed no group differences within or between groups. (E) Histological analysis of fixed transmural LV samples stained with Picro Sirius red showed increased LV fibrosis after 7 days (7d) of continuous Iso infusion in Con mice only (p = 0.02), but a between-group difference in fibrosis at 7 days was not seen. Bars = mean values; SE = error bars; values in bars = numbers of mice. Two-way ANOVA showed significant interaction of C1C2 on LV peak +dP/dt (p = 0.012), LV peak −dP/dt (p = 0.0009), and LVP (p = 0.0003); numbers above bars indicate p values from within-group post hoc comparisons (Student t-test, unpaired, 2-tailed, Bonferroni correction). Con = transgene negative mice; other abbreviations as in Figures 1 and 2.