人参二醇组皂甙对培养心肌细胞动作电位的双向性效应

DUAL-DIMENSIONAL EFFECT OF PANAXADIOL SAPONIN (PDS)ON ACTION POTENTIAL OF CULTURED CARDIAC CELLS

人参二醇组皂甙(PDS)对培养的Wistar大鼠心肌细胞动作电位呈双向性效应:低浓度使动作电位的波幅、波宽、超射、阈电位、最大舒张电位、最大除极速度等电参数一致增大;高浓度使这些电参数一致减小;无论在低浓度范围,或者在高浓度范围,电参数的改变均随PDS剂量的增大而更加显著。在电位记录前,临时向培养基中加入PDS,只表现对跨膜电活动的抑制效应。而且此效应可被肾上腺素所抵销。以上结果提示人参二醇组皂甙既有膜保获作用也有钙通道阻滞作用。

PDS may exert a dual-dimensional effect on the action potential of cultu red Wistar rat cardiac cells. Low concentration of PDS increased the amplitude and duration of the action potential, overshooting, threshold potential,the maximum diastolic potential and the maximum rate of depolarization; while high concentration of PDS decreased these parameters. It is evident that these changes of electrical parameters are dependently related to the dosage of PDS. Drastic addition of PDS to the culture medium only produced an inhibitory effect on the electrical activity across the membrane, and this effect could be antagonized by epinephrine. The results indicate that PDS has both a membrane protective effect and a calcium channel blocking effect.