Effects of verapamil preconditioning on cardiac function in vitro and intracellular free Ca2+ and L-type calcium current in rat cardiomyocytes post ischemia-reperfusion injury / 中华心血管病杂志
Chinese Journal of Cardiology
;
(12): 225-229, 2010.
Artigo
em Chinês
| WPRIM
| ID: wpr-341249
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the influences of verapamil preconditioning on cardiac function in vitro and intracellular free Ca2+ and L-type calcium current (I(Ca-L)) in rat cardiomyocytes post ischemia-reperfusion (I/R) injury.</p><p><b>METHODS</b>The isolated rat hearts in control group (37 degrees C Tyrode solution perfusion for 30 min, n = 6), I/R group (no flow for 30 min followed 30 min reperfusion with 37 degrees C Tyrode solution, n = 7) and verapamil preconditioning group [37 degrees C Tyrode solution perfusion for 10 min, adding verapamil (20 micromol/L) to Tyrode solution and perfusion for another 30 min, followed then by 30 min no flow and 30 min reperfusion, n = 7] using Langendorff perfusion system. The fluorescence intensity of intracellular Ca2+ was detected with Fluo-3/AM loading by the laser scanning confocal microscope. The I(Ca-L) was recorded via whole-cell patch clamp technique in enzymatically dissociated single rat ventricular myocytes.</p><p><b>RESULTS</b>As expected, arrhythmias and cardiac dysfunction were shown post I/R injury. The fluorescence intensities of intracellular free Ca2+ in cardiomyocytes were significantly increased compared with control group (P < 0.01). By voltage clamp protocol, peak current densities of I(Ca-L) was significantly reduced and I-V curve significantly elevated. Post I/R injury compared with control group (P < 0.01) which could be reversed by Verapamil preconditioning. Verapamil preconditioning also significantly improved diastolic and systolic functions, and reduced the incidence of arrhythmias.</p><p><b>CONCLUSIONS</b>Myocardial I/R injury might significantly impair heart functions and induce arrhythmias via cellular Ca2+ overload. Verapamil preconditioning could prevent heart I/R injury and reduce arrhythmias by decreasing influx of I(Ca-L), thereby stabilizing cardiomyocytes in myocardial stunning and avoiding occurrence of Ca2+-induced Ca2+ release during I/R injury.</p>
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Farmacologia
/
Verapamil
/
Traumatismo por Reperfusão Miocárdica
/
Cálcio
/
Ratos Sprague-Dawley
/
Precondicionamento Isquêmico Miocárdico
/
Canais de Cálcio Tipo L
/
Miócitos Cardíacos
/
Metabolismo
/
Métodos
Limite:
Animais
Idioma:
Chinês
Revista:
Chinese Journal of Cardiology
Ano de publicação:
2010
Tipo de documento:
Artigo
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