Effects of chronic amiodarone therapy on L-type calcium current recovery and action potential duration of rabbit ventricular myocytes / 中华心血管病杂志
Chinese Journal of Cardiology
;
(12): 528-531, 2009.
Artigo
em Chinês
| WPRIM
| ID: wpr-236461
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of chronic amiodarone therapy on L-type calcium current recovery and action potential duration of rabbit ventricular myocytes.</p><p><b>METHODS</b>Healthy rabbits (1.6-1.8 kg) were treated with amiodarone (80 mg x kg(-1) x d(-1)) for four weeks. Action potential duration (APD) was recorded under isolated arterially perfused left ventricular wedge preparation, then single myocytes were isolated using enzyme digestion. L-type calcium current recovery (time constant, tau) were determined by fitting data with monoexponential. Tau/APD90 were compared in cells treated with saline, amiodarone and sotalol (3 x 10(-5) mmol/L).</p><p><b>RESULTS</b>In chronic amiodarone treated myocytes, tau [(164 +/- 8) ms vs. (98 +/- 8) ms, P<0.05], APD90 [(321 +/- 12) ms vs. (220 +/- 10) ms, P<0.05] and tau/APD90 (0.51 +/- 0.03 vs. 0.44 +/- 0.03, P<0.05) were significantly increased than those in control myocytes. Sotalol significantly increased tau [(128 +/- 7) ms vs. (98 +/- 8) ms, P<0.05] and ADP90 [(405 +/- 13) ms vs. (220 +/- 10) ms, P<0.05] while reduced the tau/APD90 (0.32 +/- 0.05 vs. 0.44 +/- 0.03, P<0.05) compared to control myocytes.</p><p><b>CONCLUSION</b>The differential effect of amiodarone and sotalol on ventricular myocytes tau/APD90 ratio might be responsible for the safety profile of these two drugs.</p>
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Farmacologia
/
Fisiologia
/
Sotalol
/
Potenciais de Ação
/
Técnicas de Patch-Clamp
/
Canais de Cálcio Tipo L
/
Miócitos Cardíacos
/
Amiodarona
/
Antiarrítmicos
Limite:
Animais
Idioma:
Chinês
Revista:
Chinese Journal of Cardiology
Ano de publicação:
2009
Tipo de documento:
Artigo
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