The effects of desensitization of capsaicin-sensitive afferent neurons on the microcirculation in the stomach in rats depend on the blood glucocorticoid hormone level.

The effects of densensitization of capsaicin-sensitive afferent neurons on the microcirculation in the stomach were studied before and after administration of indomethacin at an ulcerogenic dose in adrenalectomized rats receiving and not receiving replacement therapy with corticosterone and in sham-operated animals. Measures of the microcirculation consisted of blood flow rates in microvessels in the submucous layer of the stomach and the diameter and permeability of microvessels in the mucosa. Desensitization of capsaicin-sensitive afferent neurons was performed by administration of capsaicin at a dose of 100 mg/kg for two weeks and adrenalectomy one week before the experiment. Blood flow rates in microvessels and microvessel diameters were assessed in non-anesthetized rats by direct video recording methods using a special optical system with a contact dark-field epiobjective. Administration of indomethacin at an ulcerogenic dose led to decreases in blood flow rate in microvessels in the submucous layer, dilation of superficial microvessels in the mucosa of the stomach, and an increase in their permeability. Desensitization of capsaicin-sensitive neurons potentiated indomethacin-induced impairments to the microcirculation in the submucous layer and the mucosa of the stomach. These effects of densensitization were significantly enhanced in conditions of glucocorticoid hormone deficiency. Thus, glucocorticoid hormones have favorable effects on the gastric microcirculation in rats with desensitization of capsaicin-sensitive afferent neurons.

[Effects of desensitization of capsaicin-sensitive afferent neurons on gastric microcirculation in rats depend on the blood glucocorticoid hormone level].

The effects of desensitization of capsaicin-sensitive afferent neurons on gastric microcirculation were investigated before and after administration of indomethacin at ulcerogenic dose in adrenalectomized rats with or without corticosterone replacement and in sham-operated animals. We estimated the blood flow velocity in submucosal microvessels; the diameters and permeability of mucosal venous microvessels as parameters of gastric microcirculation. Desensitization of capsaicin-sensitive neurons was performed with capsaicin at the dose 100 mg/kg two weeks before the experiment. Adrenalectomy was created one week before experiment. In vivo microscopy technique for the direct visualization of gastric microcirculation and the analysis of the blood flow was employed. Indomethacin at ulcerogenic dose decreased the blood flow velocity in submucosal microvessels, caused dilatation of superficial mucosal microvessels and increased their permeability. Desensitization of capsaicin-sensitive afferent neurons potentiated indomethacin-induced microvascular disturbances in gastric submucosa-mucosa. These potentiated effects of the desensitization are obviously promoted by concomitant glucocorticoid deficiency. Thus, glucocorticoid hormones have a beneficial effect on gastric microcirculation in rats with desensitization of capsaicin-sensitive afferent neurons.

Neuron density in the hippocampus in rat strains with contrasting nervous system excitability after prolonged emotional-pain stress.

A model system consisting of two rat strains bred for nervous system excitability in response to electric shocks was used to study changes in the number density of neurons in hippocampal field CA3 at 24 h, two weeks, and two and six months after prolonged emotional-pain stress (PEPS). Neuron density in hippocampal field CA3 decreased after completion of PEPS. These changes arose at different time points in the different rat strains (one day for low-excitability rats, two months for high-excitability rats) and persisted to six months. Thus, this is the first demonstration that persistent differential effects of stress on the number density of neurons in hippocampal field CA3, which plays an important role in learning and memory processes, depend on genetically determined constitutive characteristics of the nervous system.

[Numerical density of neurons in the hippocampus of rat lines contrasting in excitability of the nervous system exposed to prolonged emotional painful stress].

Two lines of rats, selected according to the excitability of nervous system to the action of an electric current, served as the model objects to study the changes of numerical density of neurons in hippocampus area CA3 24 hours, 2 weeks, 2 and 6 months after prolonged exposure to emotional painful stress. Reduction of neuron density in hippocampus area CA3 was demonstrated after exposure to stress that persisted as long as 6 months. These changes developed following time intervals that were different for each line of rats (24 hours for rats with low excitability and 2 month--for rats with high excitability). Thus, it was demonstrated for the first time, that prolonged differential effect of stress on numerical density of neurons in hippocampus area CA3, that plays an important role in the processes of learning and memory, depends on genetically determined constitutional peculiarities of the nervous system.

[The effects of desensitization of capsaicin-sensitive neurons on the blood flow in microvessels of the rat gastric serous muscular membrane with normal and insufficient contents of glucocorticoids].

The effects of desensitization of capsaicin-sensitive neurons on the blood flow velocity in microvessels of the gastric muscular membrane were investigated before and after indomethacin (35 mg/kg) administration in adrenalectomized rats with or without corticosterone replacement (4 mg/kg sc) and in sham-operated animals. Desensitization of capsaicin-sensitive neurons was performed with neurotoxic dose of capsaicin (20 + 30 + 50 mg/kg sc) two weeks before the experiment. Adrenalectomy was created one week before the experiment. The in vivo microscopy technique for direct visualization of gastric microcirculation and analysis of red blood cell (RBC) velocity was employed. Indomethacin decreased the RBC velocity. Adrenalectomy by itself profoundly decreased the RBC velocity, whereas corticosterone replacement prevented this effect. Desensitization of capsaicin-sensitive neurons did not influence the RBC velocity in sham-adrenalectomized rats; however, it induced further fall of both basal and indomethacin-induced RBC velocity in adrenalectomized rats that was prevented by corticosterone. We conclude that glucocorticoid hormones have a beneficial effect on the blood flow velocity in microvessels of the gastric muscular membrane in rats with desensitization of capsaicin-sensitive neurons.

[Disorder and restoration of the microcirculation in the brain of rats under deep hypothermia]. / Narushenie i vosstanovlenie mikrotsirkuliatsii v mozgu krys pri glubokoi gipotermii.

Sharp deceleration of the brain microcirculation in deep hypothermia (up to 16-18 degrees C in the rectum) is due to no irreversible alterations in the microcirculation system. Physiological controlling mechanisms of this function are preserved and help to restore the velocity of the capillary blood flow in the course of warming up of the animal.

[The adaptation-protective effect of corticosteroids on the rat gastric mucosa and its mechanism]. / Adaptatsionnyi zashchitnyi éffekt kortikosteroidov na slizistuiu obolochku zheludka krys i ego mekhanizm.

The influence of stress-induced corticosteroid production on gastric ulceration, blood flow velocity in gastric microvessels and blood pressure was studied in rats. The role of plasma corticosteroids was investigated by means of blockade of the pituitary-adrenocortical system (PACS) and following corticosterone replacement therapy (400 mu/100 g b.w.). The blockade which was induced by Fi. hydrocortisone administration (7 days before stress, 30 mg/100 g b. w.) resulted in an insufficient corticosteroid production. To evaluate the influence of corticosteroids on blood flow velocity in gastric microvessels of muscular, submucosal and mucosal coats it was used intravital microfilming by means of a dark-field contact epiobjective. Stress (water immersion + restraint) induces an ulceration, a decrease in the systemic arterial blood pressure (3 h after stress onset) and a decrease in blood flow velocity in the gastric microvessels (3 h after stress onset). In rats with insufficient corticosteroid production stress-induced ulceration, a decrease in blood pressure and gastric blood velocity were more greater than in rats with intact PACS. Replacement corticosterone therapy corrected all parameters. The results revealed that antiulcerogenic effect of stress-induced glucocorticoid production is realised owing to normalisation of gastric blood supply which is provided by an increase in systemic blood pressure.

[Corticosteroids limit the decrease in blood flow velocity in the microvessels of the gastric submucosal layer during stress in rats]. / Kortikosteroidy ogranichivaiut snizhenie skorosti krovotoka v mikrososudakh podslizistogo sloia zheludka pri stresse u krys.

To evaluate the influence of stress and corticosteroids on blood flow velocity in gastric submucosal microvessels it was used intravital microfilming by means of a dark-field contact epiobjective. The plasma filled "gap" in the continuous erythrocyte flow were used as the markers to measure linear blood flow velocity. In unstressed rats the linear blood flow velocity was equal to 2.0 +/- 0.08 mm/sec (156 microvessels, 6.4 +/- 0.14 micron in diameter), calculated volume blood flow--(6.9 +/- 0.48) x 10(-5) microliters/sec. Stress (water immersion and restraint) led to a decrease of blood flow velocity in microvessels to more than double. A stress-induced decrease of blood flow velocity was more greater in rats with insufficient corticosteroid production. The linear velocity of blood flow of these rats was lowered to 0.6 +/- 0.06 mm/sec, volume blood flow to (1.6 +/- 0.21) x 10(-5) microliters/sec. Replacement corticosterone therapy increased the blood flow velocity. It was concluded that stress decreases blood flow in microvessels of gastric submucosa. The results revealed that glucocorticoids take part in normalization of blood flow of gastric microvessels during stress and this action can provide antiulcerogenic effect of corticosteroids which was shown by us previously.

[The effect of stress and corticosteroids on the rate of blood flow in the microvessels of the gastric muscular coat of rats]. / Vliianie stressa i kortikosteroidov na skorost' krovotoka v mikrososudakh myshechnoi obolochki zheludka krys.

In order to evaluate the influence of stress and corticosteroids on blood flow velocity in microvessels of muscular coat of the stomach we applied intravital microfilming by means of a dark-field contact epiobjective. The plasma filled "gap" in the continuous erythrocyte flow were used as the markers to measure linear flow velocity. In unstressed rats the velocity was equal to 1.76 +/- 0.07 mm/sec (182 microvessels, 3.7-8.7 mu in diameter). Stress (water immersion and restraint) led to a decrease of blood flow velocity in microvessels to more than double. A stress-induced decrease of blood flow velocity was greater in rats with insufficient corticosteroid production. The velocity of blood flow in these rats was lowered to 0.62 +/- 0.04 mm/sec. Replacement corticosterone therapy increased the blood flow velocity. It was concluded that stress decreases blood flow in microvessels of muscular coat of the stomach as well as in microvessels of mucosa. The results revealed that glycocorticoids take part in normalisation of blood flow of gastric microvessels during stress.

[The microcirculation in the cerebral cortex of rats at different stages of deep immersion hypothermia]. / Mikrotsirkuliatsiia v kore golovnogo mozga krys na raznykh stadiiakh glubokoi immersionnoi gipotermii.

A 25-30 degrees C hypothermia significantly increased the capillary blood flow in the rat cerebral cortex. A deeper hypothermia (17-15 degrees C) led to a stable decrease in the blood flow up to initial level. Breathing ceased at this stage, the cardiac activity being evident for 30-40 minutes after this. Deep hypothermia also led to a reversible aggregation phenomenon which seemed not to hinder the blood flow.

[The characteristics of the circadian motor activity of sturgeons and their hybrids studied by a motion picture-TV method]. / Izuchenie osobennostei sutochnoi dvigatel'noi aktivnosti osetrovykh ryb i ikh gibridov kinotelevizionnym metodom.

Technique of slow-motion shot was used for simultaneous automatic recording of behaviour of sturgeon species Acipenser nudiventris and its hybrid with white sturgeon, Huso huso. The hybrids and the individuals of the paternal species were placed in two separate aquaria under the conditions of constant light. Cinematographic recording was performed each hour throughout 3 days during 30 s per hour. Significant differences between two kinds of sturgeons were found in the locomotor activity, trajectory of swimming, the average value and circadian rhythm of the swimming speed. The hybrid individuals swim faster and display a high peak of night activity. This puts them close to the maternal species, white sturgeon, and gives evidence of the maternal inheritance of these traits.

[The circadian rhythm of the formation of stress stomach ulcers in rats]. / Tsirkadiannyi ritm obrazovaniia stressornykh iazv zheludka u krys.

Areas of stress-induced gastric ulceration vary parallels with changes of corticosterone levels. The ulceration was greater in the morning during low basal corticosterone level than in the evening during high one. Adrenalectomy ceased the circadian basal rhythm of corticosterone and the rhythm of stress-induced ulceration. The decrease of ulceration in the evening seems to indicate an increase of the body adaptability resulting from the circadian corticosterone increase.

[An analysis of the joint activities of primates in a situation of delayed spatial choice]. / Analiz sovmestnoi deiatel'nosti primatov v situatsii prostranstvennogo otsrochennogo vybora.

A leader-dominant baboon of a couple took practically all the food in the situation of spatial delayed choice. The subdominant baboon managed to get some food, too, using fast changes of behavioral tactics during the experimental session. The obvious negative state of the subdominant baboon resulted in a severe neurotic breakdown. Long delays in the experimental scheme enabled the subdominant to get up to 50% of the food reinforcement due to the dominant baboons mistakes. The role of changes in the tactics of the monkeys is discussed.

[A quantitative analysis of primate motor activity in a situation of delayed spatial choice. The individual behavioral reactions]. / Kolichestvennyi analiz dvigatel'noi aktivnosti primatov v situatsii prostranstvennogo otsrochennogo vybora. Individual'nye povedencheskie reaktsii.

Speed of movements in food getting responses of baboons, total time of the response, trajectories of the movements and other parameters revealed obvious changes during formation of conditioned activity. The data obtained suggest that many quantitative characteristics of the primate motor activity are specifically related to various aspects of complex behavioral responses.

[Changes in the blood flow velocity in the capillaries of the rat cerebral cortex in acute massive blood loss]. / Izmenenie skorosti krovotoka v kapilliarakh kory golovnogo mozga krys pri ostroi massivnoi krovopotere.

A statistically significant drop in the blood flow velocity in capillaries of the rat cerebral cortex occurred in 50-60% loss of the blood volume: from 1.32 +/- 0.1 mm/sec to 0.2-0.8 mm/sec even in 30-40% loss, resp. A more massive blood loss (50-60%) decreased the blood flow velocity with no subsequent restoration. Aggregates of elements were formed in the capillaries with subsequent hemostasis in this part of the vessel.

[Separate flows of erythrocytes with different degrees of oxygenation in the venous vessels]. / Razdel'nye potoki éritrotsitov s raznoi stepen'iu oksigenatsii v venoznykh sosudakh.

Having studied the structure of the blood flow in pial microvessels of the rat brain, the blood flow in venules was shown to consist of separate erythrocyte flows divided by the plasma layers Visualisation of these flows is facilitated after isovolume hemodilution until the 20-25% hematocrit. The blood flows in the same microvessel were found to differ from each other essentially by the oxygen tension level and by the velocity of their transition.

[Topography and hydrodynamic heterogeneity in the terminal bed of the vessels of the gastrocnemius muscle of the cat]. / Topograficheskaia i gidrodinamicheskaia neodnorodnost' terminal'nogo rusla sosudov ikronozhnoi myshtsy koshki.

The cine-TV technique acided to reconstruct the in vivo pattern of the vascular bed surface in the m. gastrocnemius of anesthetized cats. Existence of microvascular elements (modules) was confirmed as regularly repeated every 400-500 mus along the muscular fibers. A module includes transversal (oblique) precapillary arteriole and postcapillary venule interconnected with 3-12 parallel capillaries. Mean blood velocity in the capillaries was initially 0.73 +/- 0.12 mm/sec and during postelongation hyperemia it was 0.91 +/- 0.13 mm/sec, the velocity being slower in distal capillaries. This diversity was reduced in postelongation hyperemia. Mathematical modelling of blood flow distribution over different types of modules showed the blood flow velocity in the capillaries to depend on the ratio: total resistance of incoming and outgoing vessels against the resistance of the capillary part. Along with diminishing of the ratio, the diversity of perfusion must also diminish which has been corroborated in the course of experiments.