Enhancement of Ca(2+) transients and contraction of single ventricular myocytes of rats by 5-(N,N-dimethyl) amiloride / 生理学报
Acta Physiologica Sinica
;
(6): 219-224, 2002.
Artículo
en Inglés
| WPRIM
| ID: wpr-279308
ABSTRACT
The effects of 5-(N,N-dimethyl)amiloride (DMA) (a blocker of Na(+)/H(+) exchanger or Na(+)/Ca(2+) exchanger) on calcium transient and cell contraction in isolated ventricular myocytes in normal rats and rats with myocardial hypertrophy were examined using ion imaging system with a charge coupled digital camera (CCD camera). Loading myocytes with Fura-2, electrically triggered Ca(2+) transients and cell shortening were measured simultaneously. The results showed that 10 micromol/L DMA increased Ca(2+) transient and cell shortening from 209.60+/-54.96 and 3.07+/-0.97 micrometer to 238.50+/-80.41 and 4.07+/-1.02 micrometer, respectively (P<0.05), which was completely abolished by application of KB-R7943, a specific reverse mode Na(+)/Ca(2+) exchanger blocker. After blocking L-type Ca(2+) channels by nicardipine, DMA also enhanced Ca(2+) transient and cell shortening. In rats with myocardial hypertrophy, DMA showed the common pharmacologic profile as in normal rats but more intense stimulating effects on Ca(2+) transient and cell contraction. The results suggest that DMA increase Ca(2+) transient and cell contraction via stimulating reverse mode Na(+)/ Ca(2+) exchange, and the stimulating effect is more pronounced in rats with myocardial hypertrophy than in normal ones.
Texto completo:
Disponible
Índice:
WPRIM (Pacífico Occidental)
Asunto principal:
Farmacología
/
Cardiomiopatía Hipertrófica
/
Calcio
/
Ratas Wistar
/
Intercambiador de Sodio-Calcio
/
Biología Celular
/
Miocitos Cardíacos
/
Quimioterapia
/
Amilorida
/
Ventrículos Cardíacos
Límite:
Animales
Idioma:
Inglés
Revista:
Acta Physiologica Sinica
Año:
2002
Tipo del documento:
Artículo
Similares
MEDLINE
...
LILACS
LIS