[The spectrum of the anti-ischemic activity of immobilized cytochrome c]. / Issledovanie spektra protivoishemicheskoi aktivnosti immobilizovannogo tsitokhroma c.

The antihypoxic, anti-ischemic and antianginal activity of biotechnological cytochrome c which had been immobilized on a dialdehydedextran and polyethyleneglycol carriers was studied in various experimental animals (mice, rats, rabbits). The immobilized cytochrome c exhibits higher antihypoxic and anti-ischemic activity on different models compared to cytochrome c.

[A comparative evaluation of the cardioprotective and antianginal actions of energy-providing agents]. / Sravnitel'naia otsenka kardioprotektornogo i antianginal'nogo deistviia nekotorykh énergoobespechivaiushchikh sredstv.

The limitation of a myocardial necrotic area by some energy-yielding compounds in rat coronary occlusion and their capacity to elevate the ischemia threshold in conscious rabbits were studied. Sodium malate, ascorbic acid and phosphoenolpyruvate were demonstrated to reduce the sizes of necrotic areas and increase the ischemia threshold, whereas cytochrome C and fructose-1,6-diphosphate were effective solely in limiting the infection area. It was concluded that the preventive antianginal effect of energy-yielding and electron-accepting compounds depended on their capacity to accumulate in intact cardiomyocytes.

[The characteristics of the cardioprotective action of fructose-1,6-diphosphate]. / Osobennosti kardioprotektornogo deistviia fruktozo-1,6-difosfata.

The cardioprotective effects of fructose-1,6-diphosphate (FDP) were investigated in infarcted rats and in conscious rabbits with myocardial ischemia. The influence of FDP on metabolic acidosis was studied in isolated hypoxic rat hearts. It was shown that FDP did not change the threshold of the initiation of ischemia in conscious rabbits, but decreased necrotic zone in infarcted rat hearts. After administration of FDP the myocardial contractility was prolonged significantly as compared with control under conditions of severe metabolic acidosis. However, FDP was not effective in hypoxic hearts with compensated metabolic acidosis. It was considered, that FDP influenced only ischemic myocytes with the changes in sarcolemmal permeability.

[The transient nature of myocardial ischemia during partial occlusion of the coronary artery in waking immobilized rabbits]. / Tranzitornyi kharakter ishemii miokarda pri chastichnoi okkliuzii koronarnoi arterii u bodrstvuiushchikh immobilizovannykh krolikov.

The radioactive microsphere technique was used to study mechanisms of disappearance of myocardial ischemia during partial occlusion of the left descending anterior coronary artery with implanted device in conscious immobilized rabbits. Microspheres (15 microns, NEN, USA) were injected before occlusion, immediately after ST-segment elevation and after disappearance of ST-segment shift. In ischemic region blood flow dropped by 45% (p less than 0.05) and mean blood pressure decreased by 12% (P less than 0.05) on the 1st minute of coronary occlusion. 8-15 min later ST-segment elevation disappeared and the blood flow in ischemic region became higher than control level (on the average by 35%). It is suggested that ischemia is abolished mainly by dilatation of distal coronary vessels, than by activation of collateral blood flow.

[Possibility of the pharmacologic treatment of post-ischemic myocardial damage]. / Vozmozhnost' farmakologicheskogo vozdeistviia na postishemicheskoe povrezhdenie miokarda.

The influence of ethacizin and nonachlazin on the size of myocardial necrosis, caused by 1.5-hour partial occlusion of the coronary artery was studied in conscious rabbits. The drugs were administered for 3 days, after the blood supply in the ischemic zones had been recovered. Ethacizin had a more pronounced effect, as compared to nonachlazin. The data obtained suggest that in the case of isochemic heart disease pharmacotherapy can be used not only for the prevention and arrest of anginal attacks, but also for the treatment of postischemic cardiac lesions.

[Evaluation of the antianginal action of pharmacological substances by the change in the initiation threshold for myocardial ischemia in conscious rabbits]. / Otsenka antianginal'nogo deistviia farmakologicheskikh veshchestv po izmeneniiu poroga vozniknoveniia ishemii miokarda u bodrstvuiushchikh krolikov.

The threshold of the initiation of myocardial ischemia was determined for conscious rabbits with the help of a special preliminary implanted appliance, which made it possible to perform the occlusion and reperfusion of the coronary artery. Nitroglycerin and propranolol were shown to increase the threshold of the initiation of ischemia, while dipyridamole was discovered to reduce it. The method described is offered for evaluation of the drug antianginal effect, since it is adequate and easily reproduced.

[Effect of droperidol, fentanyl and talamonal on the ischemic threshold of the myocardium]. / Vliianie droperidola, fentanila i talamonala na porog ishemii miokarda.

The authors studied the effects of neuroleptoanalgetics on the myocardial ischemia threshold in conscious rabbits. Droperidol and talamonal were capable of raising the myocardial tolerance to ischemia. However, the myocardial tolerance to ischemia diminished as the drug doses were raised. The narcotic analgetic phentanyl (0.1 microgram/kg) did not change the myocardial ischemia threshold. The tendency toward the lowering of the myocardial tolerance to ischemia was noted after administration of higher doses of phentanyl.

[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.

[Effect of nitroglycerin on the extent of experimental myocardial necrosis]. / Vliianie nitroglitserina na razmery éksperimental'nogo nekroza miokarda.

Myocardial infarction in rabbits was caused by ligation of the anterior descending artery. Nitroglycerin was injected intravenously (100 micrograms/min) from 120 to 180 minutes after the operation. The experimental group showed a rapid and statistically significant time course of changes on the ECG as compared to controls. Moreover, nitroglycerin gave rise to bradycardia in the experimental animals which was not the case either in the control group or in non-operated rabbits comprising an additional group. The size of the necrotic area measured 7 days after the operation was 41.2% larger than that in the control group.

[Effect of pharmacological substances on nociceptive vasomotor reflexes in experiments on unanesthetized animals]. / Izuchenie vliianiia farmakologicheskikh veshchestv na notsitseptivnye vazomotornye refleksy v opytakh na neanestezirovannykh zhivotnykh.

Experiments on unanesthetized cats (conscious and curarized) were made to analyze the method of studying the effect of pharmacological substances on the pressor vasomotor reflexes produced by nociceptive stimulation. It was shown that the activity profiles of the drugs depend not only on their cardiovascular properties but also on the parameters of stimulation applied to the reflex recording, which is related to the shape of the curve of reflex magnitude dependence on the stimulation intensity. The most precise test in the application of the method to the unanesthetized animals involved the recording of the threshold of reflex occurrence, with the use of curare-like drugs being mandatory. Making of experiments without use of the curare-like agents or without considering the shape of the curve of reflex magnitude dependence on the parameters of stimulation might lead to errors in the appraisal of the results obtained.

[Effect of nitroglycerin on the ino- and chronotropic function of the myocardium]. / Vliianie nitroglitserina na ino- i khronotropnuiu funktsii miokarda.

It has been shown in experiments on conscious cats that nitroglycerin exerts a cardiostimulatory effect on the myocardium. The positive inotropic effect of nitroglycerin is associated with the two processes, catecholamine release from sympathetic nerve terminals and blockade of phosphodiesterase activity. The positive chronotropic effect arises from the indirect sympathomimetic properties of nitroglycerin. In addition to the effects listed, nitroglycerin reduces the intensity of the cardiac chronotropic reactions induced by isoproterenol and produces a direct inhibitory action on the myocardium. The implication of the nitroglycerin effects in the realization of its antianginal action is discussed.

[Effect of nitroglycerin on the extent of myocardial infarction]. / Vliianie nitroglitserina na razmery éksperimental'nogo infarkta miokarda.

Myocardial infarction in rabbits was caused by ligation of the anterior descending artery. Nitroglycerin was given intravenously (100 micrograms/min) 120--180 min after the operation. In both control and experimental groups, precordial ECG maps were recorded 30, 120, 180 and 360 min after the operation. 7 days after the operation the size of myocardial infarction was measured by planimetry. Rapid and statistically significant dynamics of ECG was observed in the control group under the effect of nitroglycerin. Bradycardia under the effect of nitroglycerin was recorded in the experimental group but was not seen in the control group or in the complementary one where nitroglycerin was given to anesthetized but non-operated animals. Therefore bradycardia under the effect of nitroglycerin was observed only in animals with acute myocardial infarction. Planimetry demonstrated a statistically significant reduction of the area of necrosis in the experimental group (by 41.2%) as compared with the control one.

[Effect of anesthetics on the cardiac chronotropic reactions induced by isoproterenol]. / Vliianie anestetikov na khronotropnye reaktsii serdta, vyzvannye izoproterenolom.

Some anesthetics were shown to diminish the intensity of positive chronotropic reactions of the cat heart induced by isoproterenol. As measured by the effect exerted, the anesthetics tested can be ranged as follows: a mixture of urethane and alpha-chloralose > nembutal > hexenal > urethane, alpha-chloralose, ether. Ftorotan does not affect the intensity of these reactions. By the effect intensity urethane, alpha-chloralose, ether, hexenal and nembutal correspond with that of practolol in a dose of 15 mg/kg, while the mixture or urethane and alpha-chloralose with that of practolol in a dose of 30 mg/kg.

[Effect of nonachlazine on ino- and chronotropic function]. / Vliianie nonakhlazina na ino- i khronotropnuiu funktsiiu.

As a result of the stimulation of beta-adrenostructures of the myocardium nonachlazin intensifies ino- and chronotropic functions of the heart. This effect does not manifest after administration of practolol and is less pronounced in animals anesthesized with urethane and alpha-chloralose since the sensitivity of the beta-adrenostructures of the myocardium decreases under the influence of the anesthetics. Apart from the stimulation of ino- and chronotropic function of the heart nonachlazin reduces concurrently the intensity of positive chronotropic effect of isoproterenol. Such a combination of the efects called a "partial" beta-adrenoblockade seems likely to play an important role in the manifestation of the antianginal action of nonachlazin.

[Assessment of the influence of pharmacologic substances on pressor vasomotor reflexes in anesthetized animals]. / K otsenke vliianiia farmakologicheskikh veshchestv na pressornye vazomotornye refleksy u narkotizirovannykh zhivotnykh.

Causes accounting for differing results of experiments during studies on the effects of morphine and chlordiazepoxide upon the intensity of pressor vasomotor reflexes provoked by an electric stimulation of afferent fibers in the tibial nerve were investigated in tests set up on urethan and chloralose anesthetized animals. With this purpose in view the relationship between the amplitude of the vasomotor reflexes and the intensity of electric stimulation, as well as the nature of the drugs action upon the vasomotor reflexes, depending on the stimulation parameters adopted during their registration, were studied. The intensity and the nature of changes of the pressor vasomotor reflexes are shown to depend not only on the properties of the test drugs, but also upon the intensity of electric stimulation employed in the experiment during registration of the reflexes. The most adequate procedure for investigating the effect of pharmaceutics on the intensity of vasomotor reflexes, e. g. a study into the influence exerted by drugs on the threshold of the reflexes origination, is proposed.

[Cardiovascular effects of diazepam and chlordiazepoxide in experiments on non-narcotized animals]. / Serdechno-sosudistye éffekty diazepama i khlordiazepoksida v éksperimentakh na nenarkotizirovannykh zhivotnykh

Tests staged on non-anesthetized cats demonstrated that the symptoms of the inhibited behaviour of the animals following introduction of diazepam and chlordiazepoxide are attended by hypertension, tachycardia and an increased intensity of pressor vasomotor reflexes. Urethan and chlorasole lessened the intensity of the activating effect of the tranquilizers on the central component of the sympathetic nervous system tonicity.

[Comparative findings concerning the effect of elenium and seduxen on the cardiovascular system]. / Sravnitel'nye dannye o vliianii éleniuma i seduksena na serdechno-sosudistuiu sistemu

The authors studied the effect of seduxen and elenium on 169 patients, particularly their pulse frequency, arterial pressure, electro- and polycardiogramms in a single administration of the drugs parenterally and in a long-term per os administration. A parenteral introduction of both drugs was accompanied by a slight bradycardial effect. However, high doses of seduxen (0.34--0.5 mg/kg) lead to states of tachycardia. Unlike elenium which did not exert a hypotensive effect, seduxen displayed a mild and in some cases significant hypotensive action.