关附甲素对豚鼠心室肌细胞延迟整流钾电流的抑制作用  

INHIBITION OF GUAN FU BASE A ON DELAYED RECTIFIER CURRENT( I k) IN GUINEA PIG VENTRICULAR MYOCYTES

作　　者：王逸平[1,2,3] 陈维洲 王晓良 华峥[1,2,3] 

机构地区：[1]中国科学院上海药物研究所 [2]中国医学科学院 [3]中国协和医科大学药物研究所

出　　处：《药学学报》1996年第8期581-584,共4页Acta Pharmaceutica Sinica

摘　　要：用全细胞膜片钳制技术研究关附甲素对豚鼠心室肌细胞延迟整流钾电流的作用。结果表明，关附甲素１００μｍｏｌ·Ｌ－１对延迟整流钾电流有明显的抑制作用。去极化２２００和３８５０ｍｓ时，Ｉｋ分别由２９３±９０和２９０±９０ｐＡ减小至２２７±５９和２３１±６６ｐＡ，这种抑制作用与去极化持续时间无关。关附甲素对内向整流钾电流无影响。提示关附甲素延长心肌复极化时间似与抑制延迟整流钾电流的作用有关。Guan fu base A (GFA) is a terpenoid alkaloid isolated from the tuber of Aconitum coreanum , which has been shown to prolong cardiac repolarization in vivo and in vitro . In the present study, the effects of GFA on the delayed rectifier current( I k) were investigated using the whole cell patch clamp technique in isolated guinea pig ventricular myocytes. In the presence of CdCl 2 100 μmol·L -1 , I k was observed upon depolarizing pulses to +50 mV from a holding potential -40 mV for variable duration (550, 1100, 1650, 2200, 2750, 3300, 3850 ms). The magnitude of I k after a 2200 ms pulse was 293±90 pA prior to drug and 227±59 pA in the presence of GFA 100 μmol·L -1 . In a 3850 ms pulse, the magnitude of I k decreased from 290±90 to 231±66 pA after exposure to GFA. The inhibitory effects of GFA on I k was not dependent on the duration of depolarization. The inward rectifier current ( I k1 ) was not affected by GFA 100 μmol·L -1 . It is concluded that GFA has inhibitory effects on I k , which may contribute to its prolongation of cardiac repolarization.

关 键 词：关附甲素 心肌细胞 钾通道 抗心律失常药 

分 类 号：R972.2[医药卫生—药品]