[The characteristics of the autonomic regulation of the heart rate in patients with IHD and ventricular arrhythmias under obzidan therapy]. / Osobennosti vegetativnoi reguliatsii serdechnogo rtima u bol'nykh IBS s zheludochkovymi aritmiiami pri terapii obzidanom.

Propranolol hydrochloride was administered to 30 patients with stable angina pectoris suffering from coronary heart disease (CHD). Of them 18 patients had ventricular extrasystole, 12 had ventricular tachycardia. All the patients underwent resting ECG, bicycle ergometry, transesophageal pacing, 24-h ECG monitoring. Vegetative cardiac regulation was determined using mathematical analysis of at least 100 successive intervals R-R at rest before and after therapy (120 mg day of propranolol hydrochloride). The authors estimated characteristics of the variance analysis and two secondary values--stress index and centralization index calculated by spectral characteristics of the rhythm. Only in CHD patients with ventricular tachycardia the treatment shifted the vegetative tone in the direction of parasympathetic nervous system. It is concluded that propranolol hydrochloride affects cardiac rhythm depending on the initial condition of vegetative regulation of cardiac activity.

[Effect of the leucine enkephalin analog dalargin on the components of the sympathetico-adrenal system in experimental myocardial infarction]. / Vliianie analoga leitsin-énkefalina-dalargina-na sostoianie komponentov simpatiko-adrenalovoi sistemy pri eksperimental'- nom infarkte miokarda.

A histofluorescence study was made of catecholamine saturation of the adrenergic nervous plexuses of the intact zone of rabbit left ventricles and adrenal medullas on days 3 and 7 of experimental myocardial infarction induced by ligation of the anterior branch of the left coronary artery when dalargrin, a leucine-enkephalin analogue, was administered. Dalargin was shown to decrease catecholamine saturation of myocardial nervous plexuses and to reduce detection rates of mediator accumulation in the sympathetic axons of nervous fascicles. In addition, the agent caused a decrease in the hormone content in chromaffinocytes on day 3 of the experiment and contributed to recovery of their functional homogeneity.

[State of adrenergic innervation of intact sections of the myocardium and adrenal medulla in experimental myocardial infarction]. / Sostoianie adrenergicheskoi innervatsii intaktnykh otdelov miokarda i mozgovogo veshchestva nadpochechnikov pri éksperimental'nom infarkte miokarda.

A quantitative histofluorescence method has been employed in rabbits to evaluate adrenergic heart innervation and the adrenal glands after experimental myocardial infarction reproduced by ligation of the coronary artery (group 1). Group 2 rabbits were not subjected to interruption of the coronary blood flow. The adrenergic response was evaluated on postinfarctional days 1, 3, 7, 14 and 30. Intact animals comprised a control group 3. It was found out that the heart adrenergic plexuses of the left ventricular posterior wall demonstrated elevated luminescence intensity without changing their density in groups 1 and 2. Local accumulation of catecholamines in sympathetic axon conductive parts of the neural trunks along the coronary vessels was registered in groups 1 and 2. The luminescence intensity of catecholamines in the adrenal glands increased on day 1, 3 and 14 in group 1 and day 1 in group 2 rabbits. These findings suggest the method to be unsuitable for assessing the response of the cardiac adrenergic nerve plexuses during 30 postinfarctional days being adequate for the study of the adrenal gland response 3 days after the operation. The authors hold that relevant disadvantages can be adjusted for by introduction of mercury into the coronary channel.

[Initial experience with using phosphocreatine in patients in the early (up to 6 hours) period of myocardial infarction]. / Pervyi opyt primeneniia fosfokreatina u bol'nykh v rannie (do 6 ch) sroki razvitiia infarkta miokarda.

A randomized study of 60 patients with myocardial infarction (MI) admitted to hospital in the first 6 hours of the disease was performed in order to study the effect of phosphocreatine (PC) on the course of MI. 30 patients were treated with PC; control group consisted also of 30 patients. PC infusion in the early period of MI resulted in the decreased frequency of ventricular arrhythmias (including paroxysms of ventricular tachycardia) and lowered likelihood of cardiac failure development. No reliable influence of PC on the central hemodynamics, heart rate, heart conduction and myocardial necrosis size was determined.

[Effect of an opioid peptide on the healing of experimental myocardial infarct]. / Vliianie opioidnogo peptida na zazhivlenie éksperimental'nogo infarkta miokarda.

The effect of an opioid hormone (Leu-enkephalin analog Tyr-Dala-Gly-Phe-Leu-Arg) on the healing of myocardial infarction caused by the ligation of the descending branch of the rabbit left coronary artery has been investigated. The peptide was injected intraperitoneally at a dose of 10 micrograms/kg daily. Using light and electron microscopy, the peptide has been shown to exert a pronounced stimulating effect on the healing of the necrotic zone on days 3 and 7 of the experiment. Opioid peptides are suggested to take part in the healing of various disorders.

[Pharmacokinetics of phosphocreatine in the blood serum of man, dogs and rabbits]. / Farmakokinetika fosfokreatina v syvorotke krovi u cheloveka, sobaki i krolika.

It is shown that a single intravenous injection of phosphocreatine to man or to experimental animals is followed by its rapid clearance from blood serum. This clearance is biphasic in nature with a half-life of 3-5 min at the first rapid stage and of 20-33 min at the next slower stage. To maintain the constant phosphocreatine concentration in blood, it is necessary to infuse it at a rate comparable to that of clearance. In particular, in blood serum of man, the phosphocreatine concentration can be kept at the level of 0.2 mM if it is injected at a rate of 60 mg/h per kg bw.

[Determination of the dimensions of the heart in experimental animals using tomography based on the principle of nuclear magnetic resonance]. / Opredelenie razmerov serdtsa éksperimental'nykh zhivotnykh s pomoshch'iu tomografii, osnovannoi na printsipe iadernogo magnitnogo rezonansa.

A new method of tomography based on the principle of nuclear magnetic resonance (NMR-tomography) was used to determine the heart size in experimental animals. The study involved 25 rabbits and NMR-tomograms of their hearts were obtained both in situ and on the isolated heart. The results obtained were compared with the morphometric findings. It was found that the values of the heart size determined by NMR-tomograms as compared with the morphometric values both in situ and on the isolated heart were very similar, showing no statistical difference. When the tomographic findings were compared with the morphometric data, the correlation coefficient for the thickness of the left ventricle wall was 0.64; for the short axis of the left ventricle 0.55; for the perimeter of the left ventricle 0.70, and for the total size of the heart it equalled 0.98. It is inferred that NMR-tomography is quite adequate for taking the necessary measurements of the heart with sufficient precision.

[Effect of nonachlazine on the size of an experimental myocardial infarct]. / Vliianie nonakhlazina na razmery éksperimental'nogo infarkta miokarda.

The effect of intravenous injection of nonachlazine on the infarction size in rabbits was studied planimetrically 7 days after coronary artery occlusion. The first group rabbits received the drug 5 times every 30 minutes, beginning from the 30th minute after occlusion (the total dose 15 mg/kg). The second group rabbits were given nonachlazine 3 times a day (the total dose 12 mg/kg) during 6 days, beginning from the 2nd day after coronary artery occlusion. In both the animal groups, the drug induced respectively a 22.8 and 39.4% decrease in the necrosis size as compared to control. The effect of nonachlazine is presumably linked with stimulation of the collateral coronary circulation in the occluded zone and with the drug direct action on myocardial metabolism.

[Changes in enzyme activity in extra-infarct portions of the myocardium after administration of nitroglycerin]. / Izmenenie aktivnosti fermentov vo vneinfarktnykh uchastkakh miokarda pri vvedenii nitroglitserina.

Nitroglycerin administration to rabbits with experimental myocardial infarction induced in extrainfarctional areas of the cardiac muscle the activity of dehydrogenases of succinate, lactate, glucoso-6- phospate , glutamate, beta-hydroxybutyrate and nonspecific esterase. This suggests the intensification of the redox reactions in Crebs ' cycle, the increased utilization of fatty acids by cardiomyocytes to meet energy requirements, a decreased degree of acidosis in these myocardial sites and the intensification of glucose direct oxidation and nitrogen metabolism normalization. The beneficial influence of nitroglycerin on many metabolic processes in the intact myocardial areas during the local impairment of the coronary blood flow may account for the improvement of left ventricular contractility observed in myocardial infarction following the administration of this drug.

[Effect of intravenous administration of nitroglycerin on the indicators of central hemodynamics in patients with acute myocardial infarction]. / Vliianie vnutrivennogo vvedeniia nitroglitserina na pokazateli tsentral'noi gemodinamiki u bol'nykh ostrym infarktom miokarda.

The effect of intravenous nitroglycerin administration on central hemodynamics criteria (end diastolic pressure in the pulmonary artery and cardiac output) was analysed in a controlled study of 60 patients with acute myocardial infarction. Nitroglycerin-induced changes in the parameters were shown to be related to the hemodynamic state at baseline, with the improvement in left ventricular functional state being significant in the presence of left ventricular insufficiency and the changes minimal in the presence of normal baseline parameters. Thus, nitroglycerin can be used in patients with hemodynamic alterations without a detrimental effect.

[Effect of nitroglycerin on various enzyme activity in the peri-infarction area of the myocardium]. / Vliianie nitroglitserina na aktivnost' nekotorykh fermentov v periinfarktnoi zone miokarda.

A histochemical study of the activity of some enzymes in the peri-infarction area of rabbit myocardium in response to nitroglycerin showed the latter to increase the activity of oxydative-reductive enzymes in heart tissue, reduce acidosis, intensify the pentosephosphate cycle and contribute to a more intensive resorption of necrotized muscular fibres. These effects are conducive to better cardiomyocytes survival in the peri-infarction area and a more intensive organization of the infarction, this reducing the size of the affected area.

[Effect of nitroglycerin on the dimensions of the focal lesion in experimental myocardial necrosis]. / Vliianie nitroglitserina na razmery ochaga porazheniia pri éksperimental'nom nekroze miokarda.

In experiments on 150 rabbits with experimental necrosis of the myocardium it was shown that intravenous administration of nitroglycerin leads to decrease of morphological dimensions of the lesion and to positive dynamics of the precardial chartogram. Efficacy of nitroglycerin treatment depends on the time of administration (from the moment of ligation of the coronary artery) and the duration of its administration. The data obtained suggest the advisability of using this method on patients with acute myocardial infarction in order to limit the dimensions of the lesion.

[Histochemical study of the adrenergic innervation of the heart in experimental myocardial infarct treated by intravenous nitroglycerin administration]. / Gistokhimicheskoe issledovanie adrenergicheskoi innervatsii serdtsa pri éksperimental'nom infarkte miokarda, lechennom vnutrivennym vvedeniem nitorglitserina.

Histochemical study of the adrenergic innervation of the heart of rabbits in experimental myocardial infarction showed that the content and distribution of the mediator noradrenaline in the nerve terminals under-goes essential changes. The amount of mediator in the nerve fibers decreases not only in the zone of the infarct but also in the heart areas not involved in the infarction, particularly in the left ventricle. Changes in the fluorescence of the nerve terminals associated with redistribution of the mediator in them are described. The disorders revealed in the sympathetic nerve apparatus of the heart provide evidence that in myocardial infarction the heart reacts as a single whole; these changes may aggravate the course of the infarction. Intravenous nitroglycerin administration helps to preserve the mediator in the nerve terminals, which is regarded as a favourable effect of the drug.