• The Korean Journal of Pharmacology
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• v.23 no.1
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• pp.9-14
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• 1987

The effects of acebutolol and carbamazepine on ouabain-induced arrhythmias were investigated in rabbits. Ouabain produced ventricular arrhythmias which persisted for 7-8 min at the mean dose of $69{\pm}1.3\;{\mu}g/kg$. Ouabain arrhythmias were converted to normal sinus rhythm by administration of acebutolol or carbamazepine singly but lower dosages increased the recovery time. And then, ouabain arrhythmias were effectively converted to normal sinus rhythm and prevented by combined administration of carbamazepine and acebutolol. Each of the combined doses was ineffective when given singly. From the above results, it may be concluded that carbamazepine and acebutolol inhibited the ouabain-induced arrhythmias depending on the level of dosage and showed synergistic interaction.

• The Korean Journal of Pharmacology
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• v.11 no.2
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• pp.9-17
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• 1975

The adrenergic blocking activity and refractory period of cardiac muscle on isolated rabbit atria were measured after administration of Scutellaria. In rabbits and cats the antiarrhythmic action of Scutellaria on atrial and ventricular arrhythmias produced by epinephrine or ouabain was examined and also compared with that of propranolol and quinidine. The alcoholic extract of Scutellaria produced a marked decrease in heart rate and contractile amplitude of the isolated rabbit atria. Pretreatment with Scutellaria rendered the atria to fail to respond to epinephrine, indicating that this crude drug possesses an adrenergic blocking activity. The extract produced a marked prolongation of the refractory period of atrial muscle. The extract effectively abolished the spontaneous arrhythmia occurring in the isolated rabbit atria. As propranolol and quinidine it also suppressed the atrial arrhythmia induced by ouabain. The extract prevented, as propranolol and quinidine, the induction of ventricular arrhythmia arising from excessive dose of epinephrine in anesthetized rabbits and cats. With regard to the ventricular arrhythmia induced by a continuous infusion of ouabain, the alcoholic extract of Scutellaria exerted some suppressive effect in anesthetized rabbits but no effect on cats. From the above results, it may be concluded that Scutellaria is effective against atrial and ventricular arrhythmias. The antiarrhythmic effects of this drug may be the result of adrenergic beta receptor blocking and cardiac depressive activities including prolongation of the refractory period of cardiac muscle.

• The Korean Journal of Pharmacology
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• v.14 no.1_2
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• pp.41-46
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• 1978

The effects of sodium taurocholate(STC) and sodium deoxycholate(SDC) on cardiac function were examined by using isolated atria of rabbit and guinea pig and heart of anesthetized frog. Also the antiarrythmic action of STC and SDC on atrial arrhythmias induced by epinephrine or ouabain was studied. The results were following. The cholates exhibited a slight decrease in rate and contractile amplitude of the isolated rabbit atria. The cholates abolished partially the spontaneous arrhythmic occurring in isolated rabbit and guinea pig atria but no effect on the atrial arrhythmia induced by ouabain and epinephrine was observed. Concomitant administration of cholates with ouabain produced a marked prolongation of atrial arrhythmia in comparison to that of ouabain alone in both isolated rabbit and guinea pig atria. The cholates exhibited a marked prolongation in ventricular arrhythmia and cardiac arrest time in comparison to that of ouabain treatment. However, the combined treatment with cholates and ouabain produced a slight prolongation in comparison to that of ouabain alone in the heart of anesthetized frog. The above results suggest that cholates have a slight antiarrythmic effect on the heart but this effectiveness is different from those of propranolol that is non-selective antiarrhythmic drug.

• The Korean Journal of Pharmacology
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• v.12 no.2 s.20
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• pp.13-19
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• 1976

A fluid extract of Zizyphi Semen was employed in this experiment. The cardiac effects of Zizyphi Semen were examined on isolated rabbits atria and heart in situ of anesthetized cats and rabbits. The adrenergic blocking activity and refractory period of cardiac muscle were measured after administration of this drug. In rabbits and cats the antiarrhythmic action of Zizyphi Semen on atrial and ventricular arrhythmias produced by epinephrine or ouabain was examined. The results were following: 1. Zizyphi Semen produced a decrease in rate and contractile amplitude of the isolated rabbit atria and had a week blocking effect on epinephrine acceleration of atrial movement. 2. Zizyphi Semen effectively abolished the spontaneous arrhythmia occurring in the isolated rabbit atria ana the atrial arrhythmia induced by ouabain. 3. Zizyphi Semen produced a marked prolongation of the refractory period in isolated atrial muscle of rabbit. 4. Zizyphi Semen prevented the induction of ventricular arrhythmia arising from excessive dose of epinephrine in anesthetized rabbits and cats. 5. With regard to the ventricular arrhythmia induced by a continuous infusion of ouabain, Zizyphi Semen exerted suppressive effect and produced a marked prolongation of cardiac arrest time in anesthetized rabbits and cats. From the above results, it may be concluded that Zizyphi Semen is effective against atrial and ventricular arrhythmias. The antiarrhythmic effect of this drug may be the result of direct myocardial depressive and partially adrenergic beta receptor blocking activities including prolongation of the refractory period of cardiac muscle.