In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 103, No. 32 ( 2006-08-08), p. 12179-12184
Abstract:
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.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.0600268103
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2006
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
