Mice with the R176Q cardiac ryanodine receptor mutation exhibit catecholamine-induced ventricular tachycardia and cardiomyopathy

Proc Natl Acad Sci U S A. 2006 Aug 8;103(32):12179-84. doi: 10.1073/pnas.0600268103. Epub 2006 Jul 27.


Mutations in the cardiac ryanodine receptor 2 (RyR2) have been associated with catecholaminergic polymorphic ventricular tachycardia and a form of arrhythmogenic right ventricular dysplasia. To study the relationship between RyR2 function and these phenotypes, we developed knockin mice with the human disease-associated RyR2 mutation R176Q. Histologic analysis of hearts from RyR2(R176Q/+) mice revealed no evidence of fibrofatty infiltration or structural abnormalities characteristic of arrhythmogenic right ventricular dysplasia, but right ventricular end-diastolic volume was decreased in RyR2(R176Q/+) mice compared with controls, indicating subtle functional impairment due to the presence of a single mutant allele. Ventricular tachycardia (VT) was observed after caffeine and epinephrine injection in RyR2(R176Q/+), but not in WT, mice. Intracardiac electrophysiology studies with programmed stimulation also elicited VT in RyR2(R176Q/+) mice. Isoproterenol administration during programmed stimulation increased both the number and duration of VT episodes in RyR2(R176Q/+) mice, but not in controls. Isolated cardiomyocytes from RyR2(R176Q/+) mice exhibited a higher incidence of spontaneous Ca(2+) oscillations in the absence and presence of isoproterenol compared with controls. Our results suggest that the R176Q mutation in RyR2 predisposes the heart to catecholamine-induced oscillatory calcium-release events that trigger a calcium-dependent ventricular arrhythmia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caffeine / pharmacology
  • Cardiomyopathies / genetics*
  • Cardiomyopathies / pathology
  • Catecholamines / metabolism*
  • Central Nervous System Stimulants / pharmacology
  • Epinephrine / pharmacology
  • Genetic Predisposition to Disease
  • Male
  • Mice
  • Mice, Transgenic
  • Mutation*
  • Myocardium / metabolism*
  • Ryanodine Receptor Calcium Release Channel / genetics*
  • Ryanodine Receptor Calcium Release Channel / physiology*
  • Tachycardia, Ventricular / genetics*
  • Tachycardia, Ventricular / pathology
  • Vasoconstrictor Agents / pharmacology


  • Catecholamines
  • Central Nervous System Stimulants
  • Ryanodine Receptor Calcium Release Channel
  • Vasoconstrictor Agents
  • Caffeine
  • Epinephrine