Expression and functional role of small conductance Ca(2+)-activated K(+) channels in human atrial myocytes / 南方医科大学学报
Journal of Southern Medical University
; (12): 490-494, 2011.
Artículo
en Chino
| WPRIM (Pacífico Occidental)
| ID: wpr-307903
Biblioteca responsable:
WPRO
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression and functional role of the small conductance Ca(2+)-activated K(+) channels in human atrial myocytes.</p><p><b>METHODS</b>We collected the right atrial appendage tissues from 8 patients with congenital heart defect with sinus rhythm undergoing open-heart surgery. Immunohistochemistry was performed to identify the expression of 3 isoforms of SK channel (SK1, SK2 and SK3). Using the classical two-step enzymatic isolation method, perforated patch clamp and conventional voltage-clamp techniques were performed to record the action potentials (APs) and the whole-cell Ca(2+)-activated K(+) current (I(K, Ca)) in the single atrial myocyte. We compared the changes in action potential duration (APD) before and after the application of a specific SK channels blocker apamin (100 nmol/L).</p><p><b>RESULTS</b>Human atrial myocytes showed positivity for all the SK1, SK2 and SK3 isoform channels. Patch-clamp recording confirmed the presence of I(K,Ca), and apamin significantly prolonged APD at 90% repolarization (APD(90)), but produced no obvious effect on APD(50).</p><p><b>CONCLUSION</b>The three isoforms of SK channels are all expressed in human atrial myocytes. SK channels play a prominent role in the late phase of repolarization in human atrial myocytes, which is distinct from their functional roles in neurons where they mediate the process of afterhyperpolarization following APs.</p>
Texto completo:
Disponible
Base de datos:
WPRIM (Pacífico Occidental)
Asunto principal:
Fisiología
/
Potenciales de Acción
/
Células Cultivadas
/
Técnicas de Placa-Clamp
/
Isoformas de Proteínas
/
Apéndice Atrial
/
Biología Celular
/
Miocitos Cardíacos
/
Canales de Potasio de Pequeña Conductancia Activados por el Calcio
/
Metabolismo
Límite:
Adolescente
/
Femenino
/
Humanos
/
Masculino
Idioma:
Chino
Revista:
Journal of Southern Medical University
Año:
2011
Tipo del documento:
Artículo