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.
Artigo
em Chinês
| WPRIM
| ID: wpr-307903
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:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Fisiologia
/
Potenciais de Ação
/
Células Cultivadas
/
Técnicas de Patch-Clamp
/
Isoformas de Proteínas
/
Apêndice Atrial
/
Biologia Celular
/
Miócitos Cardíacos
/
Canais de Potássio Ativados por Cálcio de Condutância Baixa
/
Metabolismo
Limite:
Adolescente
/
Feminino
/
Humanos
/
Masculino
Idioma:
Chinês
Revista:
Journal of Southern Medical University
Ano de publicação:
2011
Tipo de documento:
Artigo
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