[The effect of verapamil on changes in the Ca2+ content of the intracellular structures of organs during acute myocardial ischemia]. / Vliianie verapamila na izmenenie soderzhaniia Ca2+ vo vnutrikletochnykh strukturakh organov v period ostroi ishemii miokarda.

In experiments on rats with acute myocardial infarction induced by occlusion of the left coronary artery in conscious animals the protective effect of verapamil on the heart, brain, liver, and kidneys in this disease was studied. The effectiveness of the drug was judged by the changes in the 45Ca2+ content in the intracellular structures (cytosol, mitochondria, endoplasmic reticulum) of the organs under study. A single injection of 200 micrograms/kg verapamil in acute myocardial infarction reduces considerably the content of 45Ca2+ in the intracellular structures of these organs and thus prevents the development of pathological processes.

[Activity of proteolytic enzymes and their inhibitors in experimental myocardial ischemia]. / Aktivnost' proteoliticheskikh fermentov i ikh ingibitorov pri ékperimental'noi ishemii miokarda.

Proteolytic activity and activity of endogenous inhibitors of endopeptidases (using chymotrypsin and papain) were studied in the myocardium of rats with experimental ischemia during an acute phase (60 min) and within 5 days after ligation of the left descending coronary artery; effects of the beta-adrenoblocking agent propranolol and the calcium antagonist verapamil on these activities was also studied. During the acute phase of ischemia, the activity of acid proteases was increased by 30%, that of Ca(2+)-activated neutral proteases by 15-20%. At the same time, the activity of serine proteases inhibitors was decreased while the activity of thiol protease inhibitors was increased. Within 5 days of coronary artery occlusion, Lysosomal thiol-dependent endopeptidases were activated in the myocardium; a considerably higher activity of the inhibitors of serine- and cysteine-containing endopeptidases was detected. The cardioactive drugs propranolol and verapamil affected selectively both endopeptidase activity and their inhibitors.

[The neurotropic and cardiotropic properties of new amino acid derivatives of isonicotinic acid]. / Neirotropnye i kardiotropnye svoistva nekotorykh novykh aminokislotnykh proizvodnykh izonikotinovoi kisloty.

Different derivatives of isonicotinic acid are used widely enough as antimicrobial and antituberculous agents. However, their neurotropic and cardiotropic effects have been studied little. The paper is concerned with investigations of these types of the activity of the new derivatives of isonicotinic acid: beta-phenyl-beta-alanine, l-proline, DL-valine, beta-alanine and DL-threonine synthesized for the first time at the Institute of Fine Organic Chemistry, Academy of Sciences of Armenia.

[The Ca2+ reactivity and the subunit composition of myocardial actomyosin during the pyromecaine and pyrroxan treatment of experimental ischemia]. / Ca2+-reaktivnost' i sub''edinichnyi sostav aktomiozina miokarda pri lechenii éksperimental'noi ishemii piromekainom i pirroksanom.

The treatment with pyromecaine and pyrroxan for 5 days was found to prevent disturbances of the physicochemical properties and the composition of the components of actomyosin complex of the rat heart left ventricle caused by experimental myocardial ischemia. Pyrroxan is able to change also the gene expression thereby leading to the appearance of a new isoform of myocardial myosin reminding by its characteristics the isoform of myosin of the rapidly contracting skeletal muscles.

[Glycerinated myocardiocyte fibers in the rat myocardium as one of the models in a preclinical assessment of antianginal agents]. / Glitserinizirovannye volokna kardiomiotsitov miokarda krys kak odna iz modelei pri doklinicheskoi otsenke antianginal'nykh sredstv.

A number of cardiotropic preparations (verapamil, obsidan, pyroxan) were studied in glycerinated fibres (GF) in the experiments on rats during five twenty four hours after ligation of coronary artery. Their ability in different degree to preserve cardiomyocyte contractile fibers from the injury of ischemic processes is revealed. Positive influence of antianginal therapy was also confirmed in the experiments with coronary artery ligation on awake animals, and in experiments on the identification of actomyosin complex components.

[Effect of anti-angina therapy on phospholipid levels of the myocardium in ischemic lesions]. / Vliianie antianginal'noi terapii na soderzhanie fosfolipidov v miokarde pri ishemicheskikh povrezhdeniiakh.

Antianginal treatment of animals with experimentally induced myocardial ischemia produced significant effects on the quantitative and qualitative composition of phospholipids: total phospholipids returned to normal levels, cardiolipins and phosphatidilinosytes were drastically increased. In ischemia, this lipid metabolism derangement appears to be of great significance as it enables the physiochemical status of biological membranes to be relatively stabilized, which is an essential condition for the enzymic system of cardiomyocytes to act.

[Antisoporific and cardiotropic properties of new amino acid derivatives of nicotinic acid]. / Antisnotvornye o kardiotropnye svoistva nekotorykh novykh aminokislotnykh proizvodnykh nikotinovoi kisloty.

On the models of urethane, nembutal and ethyl alcohol sleep it was shown that nicotinoylcapronate, nicotinoylserine and nicotinoylvaline possess antihypnotic properties being superior to those of cordiamine and on some models phenamine. Nicotinoylvaline and nicotinoylalanine normalized the myocardial contraction in animals with experimental ischemia.

[Effect of verapamil on the molecular characteristics of myocardial actomyosin in experimental ischemia]. / Vliianie verapamila na molekuliarnuiu kharakteristiku aktomiozina miokarda pri éksperimental'noi ishemii.

Verapamil was shown to be able to recover a significantly depressed actomyosin ATPase activity of the unaffected left ventricular area in experimental myocardial ischemia. The drug also increased Ca-sensitivity of the ATPase reaction, with the amount of actomyosin components (Tn-1, LCM-1, LCM-2, Tn-C) almost reaching the control level. The possibility of direct interaction of verapamil with Ca-binding sites on actomyosin macromolecule is suggested. Its influence on metabolism and gene expression is not excluded.

[Molecular mechanisms of action of ethpenal]. / Nekotorye molekuliarnye mekhanizmy deistviia étpenala.

The effect of a new cholinolytic drug ethpenal, that is applied clinically as an antiparkinsonian and antiulcer agent, on the course of experimental myocardial infarction has been studied. The experiments have shown that in the test animals (white rats and rabbits) with myocardial infarction, ethpenal increases by 9.3% the contractile function of myofibrils, makes tissue respiration return to normal, and approximates the P/O magnitude to the control level. Administration of ethpenal to the animals with experimental myocardial infarction induces a considerable increase in the content of polyglycerophosphatides, which, in its turn, leads to stabilization of the cellular membranes. The drug improves permeability of the bilayer lecithin membranes by calcium ions. A conclusion is made that the myocardial infarction, ethpenal exerts a beneficial effect on the processes occurring at a level of the cellular membranes.

Mechanism of cardiotonic action of monoethanolamine and its activity in experimental myocardial hypertrophy.

The authors investigated the cardiotonic effect of monoethanolamine (MEA) and its influence on experimental cardiac hypertrophy in albino rats. In isolated hearts, myocardial cells, and glycerinized fibres as well as in the whole organism of the animals, a distinct cardiotonic effect on MEA was observed, which was most marked in pathological states of the organism. In rats with experimental coarctation of the aorta, MEA dosed 10 mg/kg stimulated, and dosed 60 mg/kg, inhibited the development of myocardial hypertrophy, while the myocardial contractility remained sufficiently preserved. The mechanism of cardiotonic action and the inhibitory effect on the development of myocardial hypertrophy at the dosage of 60 mg/kg are apparently connected with the participation of MEA in tissue metabolic processes contributing to a normalization of tissue respiration, oxidative phosphorylation, and activation of phosphatide-generating reactions, especially to the formation of phospholipids containing ethanolamine, which represent one of the most important membrane formations and components of numerous enzymic systems.