k-strophanthin-beta and Arrhythmias--Cardiac

The antiarrhythmic activity of IST was studied on some experimental models of cardiac arrhythmia--caused by adrenaline in rats, caused by barium in non-narcotized rabbits, caused by strophanthin in guinea pigs, caused by aconitine and calcium in rats. Rhythmic disturbances were recorded by a 12-channel polyphysiograph "Galileo" or a single-channel electrocardiograph "Cardiomat". The obtained results showed that IST manifested antiarrhythmic activity in respect to adrenaline, barium and strophanthin arrhythmias without affecting substantially aconitine and calcium arrhythmias. It is thought that antiarrhythmic activity of IST, found in the indicated experimental models of cardiac arrhythmias, is most probably connected with a lowering of the peripheral sympathetic activity, realized by a central way.

Topics: Aconitine; Animals; Anti-Arrhythmia Agents; Aporphines; Arrhythmias, Cardiac; Barium; Barium Compounds; Calcium; Chlorides; Disease Models, Animal; Drug Evaluation, Preclinical; Epinephrine; Guinea Pigs; Male; Mice; Rabbits; Rats; Strophanthins

It was shown in experiments on conscious rats that intravenous injection of strophanthine in toxic doses provokes heart arrhythmias and death of the animals. Lithium drugs (lithium chloride and lithium hydroxybutyrate) injected during arrhythmias led to a short-lived effect of heart rhythm normalization. Lithium hydroxybutyrate was more effective if administered shortly after strophanthine injection, reducing the latter's cardiotoxic effect and preventing the death of the majority of the animals.

Topics: Animals; Arrhythmias, Cardiac; Chlorides; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Drug Interactions; Electrocardiography; Hydroxybutyrates; Lithium; Lithium Chloride; Male; Organometallic Compounds; Rats; Solutions; Strophanthins; Time Factors; Wakefulness

Animal experiments have shown that beta-adrenoblockers have the most marked antistrophanthin properties while antiarrhythmic agents with locally anesthetic attributes are less active. All the substances studied have proved to be ineffective on the cellular model of strophanthin arrhythmia. The data obtained suggest that the antiarrhythmic effect of the substances under study including beta-adrenoblockers is exercised on the level of the receptor apparatus of the postsynaptic membrane. The membrane stabilizing properties do not play the decisive role in ensuring the antiarrhythmic effect in strophanthin arrhythmia.

Topics: Adrenergic beta-Antagonists; Anesthetics, Local; Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Cell Membrane; Guinea Pigs; In Vitro Techniques; Strophanthins

Topics: Aged; Arrhythmias, Cardiac; Electrocardiography; Heart Atria; Humans; Male; Strophanthins

It was shown in experiments on cats that when strophanthin K injected intravenously induced ventricular arrhythmias followed by an insignificant reduction of the sympathetic activity (recorded from the cardiac nerve), lithium chloride and lithium hydroxybutyrate did not produce any effect on arrhythmia but lowered the sympathetic activity. When strophanthin-induced arrhythmias were accompanied by an increase in the sympathetic activity (animals with vagus section and denervation of the sinocarotid and cardioaortal zones), lithium hydroxybutyrate led to the diminution of the sympathetic activity and exerted antiarrhythmic effects. It is concluded that in the mechanisms of the antiarrhythmic effect an important role belongs to its depressant effect on the hyperactivated adrenergic extracardiac apparatus.

Topics: Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Blood Pressure; Cats; Chlorides; Heart Rate; Hydroxybutyrates; Lithium; Pressoreceptors; Strophanthins; Sympathetic Nervous System; Vagotomy

Topics: Animals; Arrhythmias, Cardiac; Female; Injections, Intraventricular; Male; Propranolol; Rats; Strophanthins

Topics: Arrhythmias, Cardiac; Biomedical Research; Drug Therapy; Heart Failure; Humans; Strophanthins; Tachycardia; Ventricular Fibrillation

Topics: Arrhythmias, Cardiac; Atrial Fibrillation; Digitalis; Digitalis Glycosides; Humans; Strophanthins