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. Author manuscript; available in PMC: 2022 Jun 27.
Published in final edited form as: J Am Coll Cardiol. 2020 Mar 17;75(10):1159–1174. doi: 10.1016/j.jacc.2019.12.066

FIGURE 4. β-Adrenergic Antagonist Propranolol Rescued mdx Mice From Isoproterenol-Induced Death.

FIGURE 4

(A) Kaplan-Meier survival curve demonstrated normal survival for male control (C10) mice exposed to isoproterenol (blue line) (n = 16), 100% death in male mdx mice after isoproterenol exposure (red line) (n = 13), and 54% survival in mdx mice pre-treated with propranolol and then isoproterenol (green line) (n = 13) (mdx: all male animals; mean age: 5.3 months; range: 3.4 to 5.6 months; control: all male animals; mean age: 5.3 months; range: 3.3 to 5.6). (B) Normal electrocardiograph telemetry tracing of a representative mdx mouse before treatment. (C) Sustained ventricular arrhythmias on electrocardiograph telemetry tracing of an mdx mouse after isoproterenol treatment. (D) The mdx mice treated with isoproterenol have a significantly increased number of ventricular arrhythmias compared with C10 control mice, and mdx mice pre-treated with propranolol have an incidence of ventricular arrhythmias comparable to control mice treated with isoproterenol (p < 0.05). (E) All mdx mice treated with isoproterenol died due to an arrhythmic death. (F) Representative histology sections from (a) mdx mouse exposed to isoproterenol showing high IgG (red) infiltration, suggestive of severe acute injury and fibrosis (WGA); (b) mdx mouse exposed to propranolol and isoproterenol, showing minimal acute injury; and (c) control mouse exposed to isoproterenol, showing very mild acute injury. (G) Quantification of IgG in the 2 groups. Ig = immunoglobulin; iso = isoproterenol; mdx mouse = dystrophin-knockout mouse model; prop = propranolol.