[Reversed circulation as a possible method of preventing intra-cerebral hemorrhages (experimental study)]. / Reversivnoe krovoobrashchenie kak vozmozhnyi metod preduprezhdeniia vnutrimozgovokh krovoizliianii (éksperimental'noe issledovanie).

Possibilities of reversed cerebral circulation, with arterial blood coming to cerebral tissue through the venous network and venous blood going through the arteries, were examined in acute and chronic experiments in dogs. Arterial blood pressure in cephalic veins reached 70-120 mm Hg, venous blood pressure in the circle of Willis was 5-35 mm Hg. Liquor pressure was never beyond 20-35 mm Hg. The EEG and reflex responses of the cerebral trunk were maintained for scores of minutes under acute experiment. Animals, surviving after prolonged arterialization of the cerebral venous network in chronic experiments (3-4 days), showed no central nervous or behavior disorders.

[Functional change in the cardiovascular system in respiration through an additional dead space (its importance for preventive cardiology)]. / Izmenenie funktsii serderchno-sosudistoi sistemy pri dykhanii cherez doponitel'noe mertvoe prostranstvo (znachenie dlia preventivnoi kardiologii).

Training breathing through the additional dead space improves the function of the cardiovascular system both in experimental animals and in healthy persons, increases the resistance to the effect of high-altitude hypoxia, and improves the working capacity and tolerance to physical load. The method is economical and may be used in the training of population masses under ordinary conditions.

[Changes in the cholesterol metabolism during electric stimulation of the skeletal muscles]. / Izmenneniia kholesterinovogo obmena pri élektrostimuliatsii skeletnykh myshts.

The effect of electric stimulation of the skeletal muscles on the content of cholesterol and atherogenic lipoproteins in blood serum, tissues, and bile was studied in experiments on rats subjected to long-term fixation and kept on an atherogenic diet. It is shown that electric stimulation of the muscles leads to a decrease in the content of cholesterol and atherogenic lipoproteins in blood serum and an increase in the tissue cholesterol content.

[Regulation of interrelation between pulmonary ventilation and circulation]. / O reguliatsii vzaimosviazi ventiliatsii i krovoobrashcheniia v legkikh

In acute experiments on 92 cats anesthetized with Urethane and kept under controlled respiration the mechanism of tonic activity of the pulmonary vessels was studied in the presence of a decreased partial pressure of oxygen in the alveoli. The tonicity of the pulmonary vessels was recorded during autoperfusion of the vessels of the posterior lobe of the left lung by means of a perfusion pump. Simultaneously, the pressure in the common carotid artery was recorded and the oxygen saturation of the blood was measured. Pharmacological analysis was used for the study of the mechanism of the pressor reaction of the pulmonary vessels under hypoxic hypoxy, and it demonstrated that the pression of the pulmonary vessels that develops under alveolar hypoxy is less distinct under the effect of the ganglioblocking agent Benzo-hexonium, as well as the myotropic agents Papaverine and Chloracizine. The above reaction was significantly inhibited by the blocking agents of the D- and M-serotonin-reactive structures -- Dihydroergothamine, Morphine and Novocain, and it was completely lacking against the background of the action of Izadrine and Dimedrol -- blocking agents of serotonin- and histamine-reactive structures. It can be supposed that the D- and M-serotonin-reactive, and probably also the histamine-reactive structures participate in the regulation of the interrelationship of ventilation and pulmonary circulation.

[Microelectrode study of spontaneous defibrillation of the heart ventricles]. / Mikroelektrodnoe issledovanie spontannoi defibrilliatsii zheludochkov serdtsa.

The authors investigated the cellular activity of the intact heart of guinea pigs of different age and pigeons both under normal conditions and during fibrillation. It is shown that spontaneous defibrillation is possible with high efficacy of cellular interaction. This leads to synchronization of the cellular activity, hyperpolarization of the cellular membrane and to the restoration of the normal rhythm. Increase of parasympathetic influence tends to block the mechanism of spontaneous defibrillation.

[Central mechanisms of the development of ischemic disorders of heart rhythm]. / Tsentral'nye mekhanizmy razvitiia ishemicheskikh narushenii serdechnogo ritma.

The activity of afferent and internuncial neurons of the bulbar cardiovascular centre (BCVC) was evaluated, using microelectrodes, in conditions of serotonin microinjections, altered blood gas composition and sensomotor cortical stimulation, in acute experiments in cats and rabbits. The afferent flow from ischemized myocardium was examined at the level of nodular-ganglion neurons. Cortical stimulation, changed blood O2 and CO2 proportions and the afferent message related to impaired coronary flow are shown to affect primarily the activity of internuncial BCVC neurons. Myocardial ischemia is shown to be much more frequently complicated by idioventricular arrhythmias, including ventricular fibrillations, under sensomotor cortical stimulation. Disintegrated operation of the afferent and internuncial BCVC neurons that precedes the development of severe ischemic arrhythmias may be due to a heavier afferent flow from heart receptors, descending influences from the cortical sensomotor area, and altered blood gas composition and a lower serotonin level in the medulla oblongata, associated with myocardial ischemia.

[Role of ACTH fragments in regulating electrogenesis and electrotonic synaptic interaction of pond snail neurons]. / Rol' fragmentov AKTG v reguliatsii élektrogeneza i élektrotonicheskogo sinapticheskogo vzaimodeistviia neironov ulitki prudovika.

The hypothesis of neuropeptides involvement in intercellular interaction was checked on the neurons VD1 and RPD2 connected with electrotonic synapse with two-way transmission in nerve ganglia of the pond snail. The preparation was perfused with natural and synthetic fragments of ACTH (2 X 10(-7) M). In perfusion with ACTH4-10 solution, synapse became rectified whereas in ACTH4-7 and ACTH5-10 solutions it obtained partially rectified properties. After exposure to ACTH4-7--Pro--Gly--Pro, synapse obtained rectifying properties with one--way increase in conductivity following temporary two-way increase of transmission efficiency. With the use of Pro--Gly--Pro--ACTH4-7--Pro--Gly--Pro, inhibition of the two--way conductivity occurred. Neuropeptides seem to modulate synaptic transmission. Impulse priority depends on the initial level of the cell MPs and is purposefully modulated by the peptides under test.