Role of the sarcoplasmic reticulum in the modulation of rat cardiac action potential by stretch.
Acta Physiol Scand
; 167(2): 111-7, 1999 Oct.
Article
en En
| MEDLINE
| ID: mdl-10571546
We have investigated the role of sarcoplasmic reticulum (SR) in the modulation on rat action potentials by stretch. The action potentials were recorded intracellularly from rat atrial myocytes in an isolated atrial preparation with small, physiological stretch produced by pressure (1-3 mmHg) inside the atria. The SR function was inhibited by pharmacological interventions, either with ryanodine (100 nmol L-1), thapsigargin (10 nmol L-1) or caffeine (1 mmol L-1). The duration of action potentials was increased by stretch from 1 to 3 mmHg. The repolarization indices APD30% (P < 0.05), APD60% (P < 0.01), and APD90% (P < 0.01) were all increased significantly (n=10). Ryanodine, thapsigargin, and caffeine inhibited this prolongation, or even reversed the effect with repolarization indices APD30% (P < 0.05) and APD60% (P < 0.05) which decreased in stretch with thapsigargin treatment. As a conclusion, we suggest that the SR and the intracellular calcium balance play an important role in the modulation of the shape of the rat atrial action potential during stretch.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Retículo Sarcoplasmático
/
Potenciales de Acción
/
Función Atrial
Límite:
Animals
Idioma:
En
Revista:
Acta Physiol Scand
Año:
1999
Tipo del documento:
Article
País de afiliación:
Finlandia
Pais de publicación:
Reino Unido