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用细胞内固定微电极技术观察到dl-四氢巴马汀(THP)30～100μM使家兔窦房结细胞动作电位的振幅(APA)、零相去极化速率(SP_0)和舒张期4相去极化速率(SP_4)逐渐降低,小剂量使动作电位复极90％的时程(APD_(90))延长,大剂量使其缩短,并使心率(HR)减慢。THP 30～300μM使高K~+除极和河豚毒素(TTX)所致的豚鼠乳头状肌细胞慢反应动作电位的APA、零相最大上升速率(V_(max))逐渐降低,复极50％的时程(APD_(50))缩短。实验结果提示THP可能有钙拮抗作用。
The amplitude (APA), the zero-phase depolarization rate (SP_0) and the diastolic phase 4 of rabbit sinoatrial node cells were observed by intracellular immobilization of microelectrode technique at 30-100 μM dl-tetrahydropalmatine (THP) Polarization rate (SP_4) decreased gradually. A small dose prolonged 90% of APS (APD_ (90)), shortened the dose and slowed the heart rate (HR). THP 30 ~ 300μM induced a decrease of maximal zero phase velocity (V max) of APA induced by high K ~ + depolarization and tetrodotoxin (TTX) in guinea pig papillary myocytes, and a 50% (APD_ (50)) is shortened. Experimental results suggest that THP may have calcium antagonism.