Genetic deletion of MAO-A promotes serotonin-dependent ventricular hypertrophy by pressure overload.
J Mol Cell Cardiol
; 46(4): 587-95, 2009 Apr.
Article
en En
| MEDLINE
| ID: mdl-19162038
ABSTRACT
The potential role of serotonin (5-HT) in cardiac function has generated much interest in recent years. In particular, the need for a tight regulation of 5-HT to maintain normal cardiovascular activity has been demonstrated in different experimental models. However, it remains unclear how increased levels of 5-HT could contribute to the development of cardiac hypertrophy. Availability of 5-HT depends on the mitochondrial enzyme monoamine oxidase A (MAO-A). Therefore, we investigated the consequences of MAO-A deletion on ventricular remodeling in the model of aortic banding in mice. At baseline, MAO-A deletion was associated with an increase in whole blood 5-HT (39.4+/-1.9 microM vs. 24.0+/-0.9 microM in KO and WT mice, respectively). Cardiac 5-HT(2A), but not 5-HT(2B) receptors were overexpressed in MAO-A KO mice, as demonstrated by real-time PCR and Western-blot experiments. After aortic banding, MAO-A KO mice demonstrated greater increase in heart wall thickness, heart to body weight ratios, cardiomyocyte cross-section areas, and myocardial fibrosis compared to WT. Exacerbation of hypertrophy in KO mice was associated with increased amounts of 5-HT in the heart. In order to determine the role of 5-HT and 5-HT(2A) receptors in ventricular remodeling in MAO-A KO mice, we administered the 5-HT(2A) receptor antagonists ketanserin (1 mg/kg/day) or M100907 (0.1 mg/kg/day) during 4 weeks of aortic banding. Chronic administration of these antagonists strongly prevented exacerbation of ventricular hypertrophy in MAO-A KO mice. These results show for the first time that regulation of peripheral 5-HT by MAO-A plays a role in ventricular remodeling via activation of 5-HT(2A) receptors.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Presión
/
Estrés Fisiológico
/
Serotonina
/
Eliminación de Gen
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Cardiomegalia
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Ventrículos Cardíacos
/
Monoaminooxidasa
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Mol Cell Cardiol
Año:
2009
Tipo del documento:
Article
País de afiliación:
Francia