Wang J L, Nong Y, Xia G J, Yao W X, Jiang M X
Department of Pharmacology, Tongji Medical University, Wuhan.
Yao Xue Xue Bao. 1993;28(11):812-6.
Standard microelectrode and two-microelectrodes voltage clamp techniques were used to study the effects of linesinine (Lien), an alkaloid extracted from the green seed embryo of Nelumbo nucifera Gaertn, on slow action potentials (AP) and slow inward current (Isi). Lien 10-100 mumol/L was shown to concentration-dependently decrease the action potential amplitude (APA), the maximal velocity of phase 0 depolarization (Vmax) and prolong the sinus cycle length (SCL) of slow AP in isolated sinoatrial node (SAN) pacemaker cells of rabbits. On both slow APs of rabbit SAN cells and guinea pig papillary muscles partly depolarized by high K+, Bay K 8644 0.03 mumol/L markedly increased the APA and Vmax, which were obviously antagonized by Lien 10 mumol/L. Moreover, Lien 1-100 mumol/L was found to inhibit the Isi of canine cardiac Purkinje fiber in concentration-dependent manner. Lien 3 and 100 mumol/L reduced the peak value of Isi by 14% and 88% respectively. The results suggest that Lien possesses calcium antagonistic effects.
采用标准微电极和双微电极电压钳技术，研究从莲（Nelumbo nucifera Gaertn）绿色种子胚中提取的生物碱莲心碱（Lien）对慢动作电位（AP）和慢内向电流（Isi）的影响。结果显示，10 - 100 μmol/L的莲心碱能浓度依赖性地降低家兔离体窦房结（SAN）起搏细胞慢动作电位的动作电位幅度（APA）、0期去极化最大速度（Vmax），并延长慢动作电位的窦性周期长度（SCL）。在高钾部分去极化的家兔SAN细胞和豚鼠乳头肌的慢动作电位上，0.03 μmol/L的Bay K 8644能显著增加APA和Vmax，而10 μmol/L的莲心碱可明显拮抗这种作用。此外，发现1 - 100 μmol/L的莲心碱能浓度依赖性地抑制犬心脏浦肯野纤维的Isi。3 μmol/L和100 μmol/L的莲心碱分别使Isi峰值降低了14%和88%。结果表明莲心碱具有钙拮抗作用。
