Effects of remifentanil on sinoatrial node autorhythmicity in rabbits
10.3760/cma.j.issn.0254-1416.2012.11.019
- VernacularTitle:瑞芬太尼对家兔窦房结起搏细胞自律性的影响
- Author:
Wenjie CHENG
;
Weijuan XU
;
Guiping XU
;
Xiaodong XU
;
Zhengang CAO
- Publication Type:Journal Article
- Keywords:
Piperidines;
Sinoatrial node;
Action potentials
- From:
Chinese Journal of Anesthesiology
2012;(11):1353-1356
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of remifentanil on sinoatrial (SA) node autorhythmicity in rabbits.Methods Twenty-four healthy rabbits of both sexes weighing 1.8-2.2 kg were sacrificed.Their hearts were removed and sinoatrial nodes were dissected and placed in Tyrode solution saturated with 95 ％ O2-5 ％ CO2 at 36 ℃.The action potentials of the sinus node pacemaker cells were recorded by intracellular glass microelectrode technique.The experiment was performed in 3 parts (n =8 each).Part Ⅰ:the sinoatrial node was exposed to remifentanil 2,4,8,16 and 32 ng/ml respectively.The action potentials were recorded after the sinoatrial nodes were exposed to each concentration of remifentanil for 15 min.Part Ⅱ and Ⅲ:the sinoatrial nodes were first exposed to Ca2+ channel agonist Bay K8644 0.5 μmol/L or K+ channel blocker TEA 20 nmol/L for 15 min.Then remifentanil was added until the concentration reached 16 ng/ml (final concentration) and 15 min later the action potentials were recorded.The action potential parameters included,amplitude of action potential (APA),rate of pacemaker firing (RPF),action potential duration at 90％ repolarization (APD90) and velocity of diastolic depolarization (VDD).Results Remifentanil significantly decreased,APA,RPF,VDD and prolonged APD90 in a concentration dependent manner as compared with the baseline values.Pretreatment with Bay K8644 could block the effects of remifentanil on SA node pacemaker cells,while TEA did not affect the electrophysiologic effects of remifentanil on SA node pacemaker cells.Conclusion Remifentanil exerts a negative chronotropic action on SA node pacemaker cells.These effects are likely produced by decrease in Ca2+ current,while opening of K + channels is not involved in these effects.
