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Effects of Rb 1 from the Panax notoginseng saponins on arrhythmia and Ca 2+ movement in rat heart cells
Author(s) -
Guan YongYuan,
Miao LiYan,
Sun JiaJun
Publication year - 1996
Publication title -
drug development research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.582
H-Index - 60
eISSN - 1098-2299
pISSN - 0272-4391
DOI - 10.1002/(sici)1098-2299(199610)39:2<179::aid-ddr11>3.0.co;2-7
Subject(s) - panax notoginseng , chemistry , ventricular fibrillation , isoprenaline , medicine , endocrinology , calmodulin , pharmacology , calcium , stimulation , alternative medicine , pathology
We determined the antiarrhythmic effect of Rb 1 (from Panax notoginseng ) on different arrhythmia models and its effect on cytoplasmic Ca 2+ concentrations ([Ca 2+ ]i) in rat heart cells with fura‐2 fluorescence. At doses of 30 and 50 mg/Kg, Rb 1 produced an antirrhythmic effect on BaCl 2 ‐induced ventricular tachyarrhythmia in rats, atrial fibrillation induced by CaCl 2 ‐ACh, and ventricular fibrillation induced by chloroform in mice. The rest [Ca 2+ ]i was 108 ± 10.7 nM in the freshly isolated rat heart cells. Sixty mM KCl caused an increase in [Ca 2+ ]i to 379.4 ± 77 nM. Rb 1 from 0.1 to 0.8 mM significantly reduced this increase in a concentration‐dependent manner. mM Rb 1 (0.4 mM) also completely inhibited the increase in [Ca 2+ ]i induced by 1 μM isoprenaline. The radioligand binding study in rat heart cells showed that Rb 1 did not change the B max and K d values of [ 3 H]‐dihydroalprenolol binding. These data suggest Rb 1 can inhibit Ca 2+ entry through voltage‐dependent and receptor‐linked Ca 2+ channels, and that this is related to its antiarrhythmic effect. Drug Dev. Res. 39:179–183. © 1997 Wiley‐Liss, Inc.