Abstract: The effects of ginsenoside B on His-bundle electrogram (HBE) and monophasic action potential (MAP) of rabbit hearts were studied by cardio- catheter method and suction electrode method respectively. The A-H, H-V intervals of HBE were not affected by ginsenoside B. Ginsenoside B (l mg/kg) shortened the plateau phase of MAP, but had no influence on APA, Vmax, and APD of MAP. The results suggest that ginsenoside B may exert blockage of the slow calcium channel without any apparent effect on the conduction system of the heart.

Key words: Ginseng, Ginsenoside, His-bundle electrogram, Monophasic action potential