veratrine and Arrhythmias--Cardiac

In this study, we attempted to identify the interactions and mechanisms between veratrine and paeoniflorin on isolated rat atria. Paeoniflorin alone showed no effect on the rat atria. Veratrine increased the atrial contraction and induced arrhythmia at 1 x 10(-5) g/ml. Veratrine could directly induce contraction and elicit tetanic contraction at 1 x 10(-4) g/ml in the left atria with or without electric stimulation. Paeoniflorin (4.8 x 10(-6) to 4.8 x 10(-3) g/ml), verapamil (2.2 x 10(-6) g/ml), tetrodotoxin (TTX) (3.2 x 10(-8) g/ml) and quinidine (7.5 x 10(-6) g/ml) inhibited the increase of contraction and delayed the onset of contraction induced by veratrine (1 x 10(-5) g/ml). The inhibitory effect of paeoniflorin combined with verapamil on the contraction induced by veratrine was more potent than that of paeoniflorin or verapamil alone. However, the inhibitory effect of paeoniflorin was not potentiated by TTX or quinidine. From the above results, the contraction evoked by veratrine in the rat atria may be concluded to be caused by the stimulation of Na(+)- and Ca(2+)-ion channels. The inhibition of paeoniflorin on the contraction induced by veratrine may primarily be related to the blockade of Ca2+ channels.

Topics: Animals; Arrhythmias, Cardiac; Benzoates; Bridged-Ring Compounds; Calcium Channels; Glucosides; Heart Atria; Herb-Drug Interactions; In Vitro Techniques; Male; Monoterpenes; Myocardial Contraction; Phytotherapy; Plant Extracts; Plants, Medicinal; Rats; Rats, Wistar; Sodium Channels; Time Factors; Veratrine

Topics: Animals; Arrhythmias, Cardiac; Cyclic AMP; Epinephrine; Free Radicals; Myocardial Reperfusion Injury; Myocardium; Rats; Rats, Inbred Strains; Taurine; Veratrine

Topics: Acetylcholine; Animals; Arrhythmias, Cardiac; Blood Pressure; Butyrates; Carotid Arteries; Cats; Chemical Phenomena; Chemistry; Denervation; Electric Stimulation; Electrocardiography; Ganglia, Autonomic; Heart; Heart Rate; Muscle Contraction; Muscles; Neostigmine; Propionates; Vagus Nerve; Vascular Resistance; Veins; Veratrine

Topics: Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Humans; Veratrine

Topics: Animals; Arrhythmias, Cardiac; Diterpenes; Dogs; Heart; Humans; Protoveratrines; Vasoconstrictor Agents; Vasodilator Agents; Veratrine; Veratrum Alkaloids