【摘要】 用离体豚鼠心乳头肌观察了DL-四氢巴马汀对正常心肌细胞动作电位和收缩力的影响。结果表明,DL-四氢巴马汀产生浓度依赖性负性肌力作用;同时明显缩短APD₂₀和APD₅₀,但APD₉₀和ERP延长,RP降低,对APA和Vmax影响较小。出现兴奋-收缩脱偶联。此外,豚鼠皮内注射DL-四氢巴马汀使局部刺激疼痛减弱,蟾蜍离体神经法观察到DL-四氢巴马汀使神经干动作电位振幅降低,表明该药具有局部麻醉作用,但较奎尼丁弱。实验结果提示DL-四氢巴马汀主要阻滞Ca²⁺内流,但对Na⁺内流、K⁺外流也有阻滞作用。更多还原

【Abstract】 The effects of DL-tetrahydropalmatine （THP）on action potentials and contractilies of isolated giunea pig papillary muscle cells were observed with the microelecorode technique. THP(10^-5-3x10^-4M)could produce a dose-dependent negative inotropic effect. THP（0.1 mM）could shorten APD₂₀ and APD₅₀ evidently （p<0.01）, prolong APD₉₀ and ERP, and decrease RP. The effects of THP on APA and Vmax were smaller. This showed excitationcontraction uncoupling. The intradermic injection of THP could allenuate local stimulated pain in guinea pigs. Also ,THP could decrease the action potential amplitude of isolated sciatic nerves in toads, indicating that THP possesses a local anesthetic action, weaker than that produced by quindine. The results show that THP inhibits not only the influx of calcium, but also the influx of sodium and the out flow of Potassium.更多还原