摘要
用膜片钳全细胞法研究关附甲素（ＧＡ）对单个心室肌细胞钠通道电流（ＩＮａ）的频率依赖性和使用依赖性影响。结果：４０μｍｏｌ／ＬＧＡ在刺激频率０．５，１．０，２．０Ｈｚ时使ＩＮａ峰值由用药前的７．９３±２．３ｎＡ分别降至４．８１±１．３，３．２３±１．１和１．２８±０．８ｎＡ（ｎ＝８，Ｐ均＜０．０５），抑制率分别是３９．３％、５９．３％和８３．９％。在脉冲串刺激时，维持电位－９０ｍＶ、指令电位－３０ｍＶ，灌流前ＩＮａ为７．６９±１．３３ｎＡ；４０μｍｏｌ／ＬＧＡ灌流后第１，１０，２０，３０个脉冲ＩＮａ分别是４．２４±０．９８，３．２５±０．７４，２．３３±０．６４和２．０６±０．７０ｎＡ（ｎ＝６，Ｐ均＜０．０１）；而在维持电位－８０ｍＶ，指令电位－３０ｍＶ时，ＧＡ灌流前ＩＮａ为７．５１±１．４３ｎＡ，在灌流后第１，１０，２０，３０个脉冲分别是４．１９±１．０９，２．２８±０．４１，１．２７±０．２４和０．８９±０．２５ｎＡ（ｎ＝６，Ｐ均＜０．０１）。提示：ＧＡ抑制ＩＮａ具有频率依赖性及使用依赖性，其频率依赖性和使用依赖性的机理相同。
The frequency and usedependent blocking effects of Guanfu base A(GA) on sodium channel current were investigated in isolated single ventricular cell from guinea pig hearts using patch clamp wholecell recording.The results suggested that 40 μmol/L GA reduced peak value of sodium channel current (INa) from 7.93±2.3 nA to 4.81±1.3 nA(39.3%),3.23±1.1 nA(59.3%) and 1.28±0.8 nA(83.9%) at stimulating frequency 0.5,1.0,2.0 Hz respectively(n=8,P<0.05).During train pulse stimulation,when holding potential was -90 mV,command potential was -30 mV,40 μmol/L GA decreased INa from 7.69±1.33 nA to 4.24±0.98 nA,3.25±0.74 nA,2.33±0.64 nA and 2.06±0.70 nA at the 1st,10th,20th,30th pulse number respectively (n=6,P<0.01).while holding potential was -80 mV,command potential was -30 mV,40 μmol/L GA inhibited INa from 7.51±1.43 nA to 4.19±1.09 nA,2.28±0.41 nA,1.27±0.24 nA and 0.89±0.25 nA at the 1st,10th,20th,30th pulse number respectively (n=6,P<0.01).It reveals that GA block sodium channel current in frequency and usedependent manner.The frequency and usedependent blocking effects of GA on sodium channel are the same phenomenon.
出处
《中国心脏起搏与心电生理杂志》
1998年第1期49-50,共2页
Chinese Journal of Cardiac Pacing and Electrophysiology
关键词
膜片钳
心室肌细胞
钠通道
频率依赖性
Patch clamp Ventricular myocyte Sodium channel Frequencydependent Usedependent
