Cardiotoxic effects of the antiarrhythmic rhythmidazol and their correction by suphan, befol, and their combinations

The antiarrhythmic rhythmidazol produces a cardiotoxic effect that can be corrected by suphan, befol, and their combinations, as evidenced by normalization of ultrastructural organization of cardiomyocytes and myocardial oxygen consumption by these drugs. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 12, pp. 640–644, December, 1997     

Effect of suphan, lidocaine, and their combination on early occlusion and reperfusion arrhythmias in cats

It is shown that the nonglycoside cardiotonic drug suphan exhibits antiarrhythmic and antifibrillatory activity, although less pronounced than that of lidocaine. When lidocaine was administered after suphan, the antifibrillatory effects of both preparations increased. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 545–547, May, 1997     

Comparison of antiarrhythmic activities of befol,lidocaine, and bonnecor

The antiarrhythmic activity of befol (an isotoxic dose) is higher than (or comparable to) that of lidocaine and bonnecor in atrial and ventricular arrhythmias induced by acute ischemia, reperfusion, myocardial infarction, or ouabain treatment. In epinephrine-induced arrhythmia, befol is inferior to these drugs (except lidocaine) in activity and range of therapeutic action. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 12, pp. 665–668, December, 1996     

Comparative analysis of acute toxicity of amino acid-containing antiarrhythmics

Acute toxicity of amino acid-containing antiarrhythmic agents is experimentally studied in mice. Introduction of amino acids into the antiarrhythmic molecules always reduces their toxicity. However, the same amino acids unequally modulate toxicity of different antiarrhythmic drugs. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 2, pp. 215–217, February, 1999     

Antiarrhythmic effect of hypoxic preconditioning is mediated by activation of μ- and δ-opioid receptors

Adaptation of rats to repetitive hypoxia leads to a decrease in the severity and frequency of arrhythmias induced by epinephrine. Naloxone abolishes antiarrhythmic effect of adaptation. Activation of μ-and δ-opioid receptors is one of the important factors mediating antiarrhythmic effect of adaptation. Intravenous administration of acetorphan, an enkefalinase inhibitor, produces statistically significant antiarrhythmic effect in the control group. Thus, the antiarrhythmic effect of hypoxic adaptation results from activation of μ-and δ-opioid receptors due to increased level of endogenous enkefalins. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 3, pp. 272–274, March, 1997     

Dependence of the antiarrhythmic effect of laser radiation on the rate,duration, and site of exposure

Acute experiments on cats narcotized with nembutal using the same model of ischemic disturbances of cardiac rhythm reveal that the antiarrhythmic effect of laser depends on the rate and duration of exposure, while its degree of expression depends on the site exposed to radiation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, No 3, pp. 246–248, March, 1995 Presented by V. N. Yarygin, Member of the Russian Academy of Medical Sciences     

Antiarrhythmic activity of GABA derivative TZ-50-2

The GABA derivative TZ-50-2 exerted pronounced antiarrhythmic effects on a variety of arrhythmias (atrial, ventricular, and mixed). The drug was superior (or at least comparable) to quinidine, procainamide, lidocaine, verapamil, bonnecor, and other reference drugs in antiarrhythmic activity and therapeutic range, and showed no cardiotoxicity. The antiarrhythmic effects of TZ-50-2 were due to modulation of calcium and sodium channels. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 4, pp. 415–418, April, 1999     

Comparative study of Na-blocking properties of antiarrhythmic drugs on isolated rat cardiomyocytes

The effects of the antiarrhythmic preparations lidocaine, flecainide, and rhlocaine on sodium concentration in cardiomyocyte cytoplasm are studied using the Na-sensitive fluorescent probe SBFI. The Na-blocking effect of lidocaine and rihlocaine depends on the frequency of electrical stimulation of cardiomyocytes (0.2–1.0 Hz). The data suggest the possibility ofin vitro testing of novel antiarrhythmic drugs. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 6 pp. 666–668, June, 1997     

Antiarrhythmic activity of the antiopioid peptide nociceptin and its effect on the fast Na+ channels in cardiomyocytes

The antiopioid peptide nociceptin does not affect heart resistance to the proarrhythmic effect of epinephrine or calcium chloride, but it produces an antiarrhythmic effect in the aconitine arrhythmia model. Nociceptin prolongs the QRS interval and does not affect heart rate and duration of the RQ interval. The antiarrhythmic effect of nociceptin is not related to changes in the tone of the autonomic nervous system. Nociceptin is supposed to block fast Na⁺ channels in cardiomyocytes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 12, pp. 655–657, December, 1998     

Comparative characteristics of antiarrhythmic activity of phencarol and dimebone in neurogenic ventricular fibrillation

The antihistamine drugs (H₁-blockers) dimebone and especially phencarol exhibit antiarrhythmic activity under conditions of neurogenic ventricular fibrillation. The antiarrhythmic activity of phencarol is associated with pronounced vagolytic effect, while that of dimebone is due to both vagolytic and moderate cardiotropic effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 81–85, July, 1997     

Effect of biotechnological cytochromec on the early postocclusion and reperfusion arrhythmias

Biotechnological cytochromec showed a lower antiarrhythmic activity in cats with acute occlusion and reperfusion arrhythmias than trimecaine, verapamil, and quaternidine but a higher activity than anapriline. Under experimental conditions, cytochromec potentiated the antiarrhythmic effect of trimecaine and quaternidine. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 1, pp. 89–91, January, 1999     

Antiarrhythmic properties of Dimebon

The H₁-receptor blocker Dimebon is shown to exhibit pronounced antiarrhythmic properties. Its activity and therapeutic action range (toxic/therapeutic ratio) exceed those of quinidine, ethmosine, isoptin, and bonnecor in several animal models of cardiac arrhythmia. The mechanism of its antiarrhythmic action is probably associated with blockade of sodium and particularly calcium channels, prolongation of the effective refractory period, and slowing of impulse traffic in the conduction system of the heart. Dimebon may be recommended for submission to clinical trials as an antiarrhythmic agent. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 375–377, April, 1995 Presented by B. A. Lapin, Member of the Russian Academy of Medical Sciences     

Opiatergic mechanisms of cardioprotective and antiarrhythmic effects of adaptation

Adaptation to hypoxia and short-term immobilization stress, as well as preconditioning with Rhodiolae rosea extract produces pronounced antiarrhythmic and cardioprotective effects in the model of adrenergic damage to the heart. Preliminary blockade of opioid receptor significantly decreases the protective effect of adaptation. Using selective opiate receptor antagonists (naltrindole, ICI 174,864, and norbinaltorphimine) we show that the antiarrhythmic effect of adaptation is mediated predominantly via activation ofk-receptors, and to a lesser extent μ-and σ-receptors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 2, pp. 167–170, February, 1999     

Opiatergic mechanisms of the antiarrhythmic effect of adaptation

A decrease in the severity and occurrence of epinephrine- and CaCl₂-induced cardiac arrhythmias and an increase in the β-endorphin and enkephalin contents in the brain, myocardium, adrenals, and blood plasma are observed in rats adapted to stress. The antiarrhythmic effect of adaptation is abolished by naloxone. A single administration of D-kyotorphin, a liberator of endogenous peptides, to intact animals also increases the resistance to arrhythmogenic factors. Intravenous administration of the enkephalinase inhibitor RB101 produces a significant antiarrhythmic effect in control animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 276–278, September, 1996     

Clinical and experimental study of antiarrhythmic and antianginal effects of quaternidine

High antiarrhythmic activity of a new Russian antiarrhythmic drug quaternidine in ventricular arrhythmia was studied in 96 coronary patients by Holter monitoring, bicycle ergometry, and echocardiography. The drug had a positive impact on local kinetics in left-ventricular ischemic myocardium and some parameters of bicycle exercise test. The preparation possesses no arrhythmogenic effect. Experiments on 30 random-bred rats showed that the drug reduced the necrotic zone under conditions of experimental coronary occlusion. Experiments on 14 intact cats demonstrated that quaternidine had no effect on coronary bloodflow. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 130, No. 11, pp. 581–584, November, 2000     

Modeling of tachyarrhythmias in conscious animals

A model for reproduction of sustained tachyarrhythmias in conscious animals is developed. Adequacy of the model and the possibility of using it for screening of antiarrhythmic drugs are demonstrated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 8, pp. 237–240, August, 1997     

Antiarrhythmic activity of amiodarone in neurogenic atrial fibrillations

Acute experiments on cats showed that dynamics of amiodarone antiarrhythmic activity with respect to neurogenic atrial fibrillations correlates with its neurotropic effects rather than its cardiotropic activity. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 3, pp.308–310, March, 1999     

Effect of SOD and NO donor on reperfusion-induced rhythm disturbances in rats

Individual infusion of SOD and NO donor produces an antiarrhythmic effect, although does not completely prevent reperfusion-induced arrhythmias, while the combination of the antiradical agent and NO donor provides the most efficient protection of reperfused myocardium due to summation of their effects. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 7, pp. 137–140, February, 1999     

A mechanism of antiarrhythmic effect ofRhodiola Rosea

It is shown that autonomic nervous system participates in the preventive antiarrhythmic effect ofRhodiola rosea. The effect of the preparation is presumably mediated through modulation of the sympathetic nervous system. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 4, pp. 424–426, April, 1998     

Antiarrhythmic effects of μ-opiate receptor agonists in rats with epinephrine-induced arrhythmias: Role of the vegetative nervous system

The μ-opiate receptor agonists DAGO and DALDA preinjected intravenously in a dose of 0.1 mg/kg prevented the occurrence of arrhythmias in rats injected with epinephrine. Their antiarrhythmic activity was not modified by atropine or hexamethonium. It is concluded that the vegetative nervous system plays no substantial role in mediating the antiarrhythmic effects of DAGO and DALDA, and that these effects are most likely associated with stimulation of cardiac opiate receptors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 7, pp. 25–27, July, 1996