摘要
用全细胞膜片钳制方法观察了中药白花前胡有效成分白花前胡甲素(Pd一Ia)对豚鼠·C室肌单细胞迟发性外向钾电流(Ik)的影响。Pd一Ia以剂量依赖的方式增加Ik,其阈浓度接近lnmol·L-1,EC50约0.2μmol·L-1,最大效应浓度约1μmol·L-1增加Ik2.5±0.5倍(P<0.01),Pd一13的此种作用通过冲洗可部分消退。从电流一电压关系可知:人的激活电压接近40mV,lpmol·L-1pd一Ia使V1/2最大左移7mV,曲线的斜率改变-0.65mV,经比较无统计学意义,提示Pd一Ia对Ik的激活动力学过程无明显影响。以上结果表明,Pd一Ia能促进K+通道开放。
By using a whole-cell patch clampmethod,the effect of d1-praeruptorin A(Pd-Ia)ondelayed outward potassium current(Ik)was investi-gated in single ventricular cell of guinea pig. Pd-Iaenhaneed Ik dose-dependently.Its threshold concen-tration for activating Ik was near 1 nmol·L-1,theEC50 was 0.2 μmol·L-1,and the maximum effectiveconcentration was 1 μmol·L-1.Pd-Ia increased Ikbv2.52± 0.53 folds(P<0.01,n=5),and the effectcould be reversed by washing.I-V relationship show-ed that the activated potential of Ik was near-40mV, V1/2(half-maximum voltage) shifted about 7mV in the negative direction,and the slope of thecurve changed -0.65 mV(P>0.05,n=5).These re-sults indicated that Pd-Ia could open the K+ chan-nel and increase Ik.It might be a new potassium chan-nel opener.
出处
《中国药理学与毒理学杂志》
CSCD
北大核心
1995年第3期192-195,共4页
Chinese Journal of Pharmacology and Toxicology
关键词
白花前胡甲素
心肌细胞
动作电位
钾外流
calcium channel blockers:d1-praeruptorin A
delayed outward potassium cur-rent
patch clamp method
whole-cell
potassiumchannel