摘要
目的 :观察西洛他唑对大鼠右心室肌细胞瞬间外向钾电流 (Ito1)的影响 ,探讨西洛他唑抗心律失常作用的确切机制。方法 :酶解法分离SD大鼠右心室肌细胞 ,采用全细胞膜片钳技术记录右心室肌细胞Ito1。结果 :5 0 μmol/L西洛他唑显著降低Ito1,使Ito1幅值由加药前 (12 .7± 0 .5 ) pA/ pF降至 (7.6± 0 .4 ) pA/ pF ,降低 (4 0 .1± 3.0 ) % (P <0 .0 1,n =9)。在 1～ 5 0 μmol/L范围内 ,西洛他唑的作用呈浓度依赖性 ,半抑制浓度为 (17.2±2 .2 ) μmol/L。此外 ,该药对Ito1电压依赖性的激活和失活曲线无显著影响。结论 :西洛他唑浓度依赖性地阻滞大鼠右心室肌细胞的Ito1。
Objective:To explore the effect of cilostazol on transient outward potassium current (I to1) in isolated rat right ventricular myocytes, and its anti-arrhythmic mechanism.Method:The whole-cell patch clamp technique was used to record I to1 in myocytes enzymatically isolated from the SD rat right ventricle.Result:Cilostazol of 50 μmol/L significantly decreased I to1(with the test potential of +50 mV). The peak amplitude of I to1 decreased from ( 12.7± 0.5) pA/pF to ( 7.6± 0.4) pA/pF [by( 40.1± 3.0)%, P< 0.01 vs control, n=9]. In addition, the drug of 1～50 μmol/L inhibited the current in a concentration-dependent manner with an IC 50 of ( 17.2± 2.2) μmol/L. Furthmore, cilostazol did not affect the voltage dependence of activation and inactivation curve of I to1.Conclusion:The present study demonstrated that cilostazol inhibited I to1 in rat right ventricular myocytes.
出处
《临床心血管病杂志》
CAS
CSCD
北大核心
2004年第3期169-171,共3页
Journal of Clinical Cardiology
