Ionic Mechanisms of Desflurane on Prolongation of Action Potential Duration in Rat Ventricular Myocytes
Yonsei Medical Journal
;
: 204-212, 2012.
Artigo
em Inglês
| WPRIM
| ID: wpr-145830
ABSTRACT
PURPOSE:
Despite the fact that desflurane prolongs the QTC interval in humans, little is known about the mechanisms that underlie these actions. We investigated the effects of desflurane on action potential (AP) duration and underlying electrophysiological mechanisms in rat ventricular myocytes. MATERIALS ANDMETHODS:
Rat ventricular myocytes were enzymatically isolated and studied at room temperature. AP was measured using a current clamp technique. The effects of 6% (0.78 mM) and 12% (1.23 mM) desflurane on transient outward K+ current (I(to)), sustained outward current (I(sus)), inward rectifier K+ current (I(KI)), and L-type Ca2+ current were determined using a whole cell voltage clamp.RESULTS:
Desflurane prolonged AP duration, while the amplitude and resting membrane potential remained unchanged. Desflurane at 0.78 mM and 1.23 mM significantly reduced the peak I(to) by 20+/-8% and 32+/-7%, respectively, at +60 mV. Desflurane (1.23 mM) shifted the steady-state inactivation curve in a hyperpolarizing direction and accelerated inactivation of the current. While desflurane (1.23 mM) had no effects on I(sus) and I(KI), it reduced the L-type Ca2+ current by 40+/-6% (p<0.05).CONCLUSION:
Clinically relevant concentrations of desflurane appear to prolong AP duration by suppressing Ito in rat ventricular myocytes.
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Potenciais de Ação
/
Canais de Potássio
/
Ratos Sprague-Dawley
/
Técnicas de Patch-Clamp
/
Anestésicos Inalatórios
/
Canais de Cálcio Tipo L
/
Miócitos Cardíacos
/
Sistema de Condução Cardíaco
/
Ventrículos do Coração
/
Isoflurano
Limite:
Animais
Idioma:
Inglês
Revista:
Yonsei Medical Journal
Ano de publicação:
2012
Tipo de documento:
Artigo
Similares
MEDLINE
...
LILACS
LIS