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Biomedical subjects

Iu M Shtykhno

Publications and source records attributed to Iu M Shtykhno.

At least 19 recordsLinked to original sources
PubMed1984

[Mesenteric microvessel reactivity in rats in mesenteric shock].

Reactivity of rat mesenterial microvessels was studied during mesenterial shock. The development of the shock was discovered to involve two phases in the changes of microvascular reactivity. The sensitivity of microvessels to adrenaline was increased at the beginning of the shock whereupon it started descending. This phenomenon evidences that vasodilatation occurring at the late stages of the shock development is determined not only by a reduction in the concentration of endogenous adrenaline and noradrenaline but also by a decrease in the sensitivity of microvessels to these agents. The data obtained make it possible to explain the mechanism of steady vasodilatation in response to injection of exogenous adrenaline and noradrenaline, which is seen at the late stages of mesenterial shock.

Animals↗
PubMed1982

[Microcirculation and oxygen tension in the cerebral cortex of rats with hemorrhagic shock].

Microcirculatory disturbances in pia mater are followed by change in oxygen tension in the brain cortex. Immediately after bleeding initial decrease of oxygen tension by 60-70% of the basal level was observed. This decrease was induced by initial vasoconstriction and brain cortex hypoxia. After compensation of blood circulation supervened and the cortical blood flow was set to a lower level (30-40 minutes after the decrease), there occurred a phase of oxygen level stabilization. The oxygen tension remained unchanged for a long time and decreased very slowly. More rapid fall of oxygen tension was noticed only at the end of the fourth hour when circulation decompensation set in.

Animals↗
PubMed1980

[Effect of trypsin on intravascular erythrocytes aggregation].

The role of proteolytic enzymes in intravascular aggregation of red cells was studied in experiments on rats by intravital microscopy. Intravenous injection of trypsin (40--50 mg/kg) combined with heparin (1000 units/kg) produces marked intravascular aggregation of red cells. Preliminary infusion of pentoxyphyllin (20 mg/kg) or acetylsalicylic acid (100 mg/kg) blocked this process. A conclusion is made about an important role of proteolytic enzymes play in the development of microcirculatory disorders. A possible mechanism of the aggregating action of trypsin and approaches to its correction are discussed.

Animals↗
PubMed1980

[Effect of acetylsalicylic acid and pentoxifylline (trental) on intravascular erythrocyte aggregation stimulated by arachidonic acid].

The role of arachidonic acid (3--5 mg/kg animal body weight) in the intravascular red cell aggregation was studied on rats by intravital microscopy. It has been established that intravenous injection of arachidonic acid leads to aggregation and red cell hemolysis, and animals' death. Preliminary injection of acetylsalicylic acid or pentoxyphylline prevents the initiation of aggregation and lysis of red cells but does not avert the animals' death because of arachidonic acid. It is concluded that arachidonic acid plays an important role in aggregation and lysis of red cells. It is recommended that reasons for animals' death because of arachidonic acid in the absence of microcirculatory disorders be studied.

Animals↗
PubMed1978

[Experimental analysis of the humoral mechanism of microcirculatory disorders following thermal and mechanical traumatic shock in experiments on parabiotic rats].

In experiments on parabiotic rats with crossed circulation and separate innervation mechanical or burn trauma of one of the partners was followed by shock-like condition of the other one, and by microcirculatory changes in the mesentery typical of burn or traumatic shock. It shows that in burn shock, as well as in traumatic one, the detected changes in microcirculation are due to humoral, but not to neural factors.

Animals↗
PubMed1977

[State of nutritive circulation in rats following long-term limitation of motor activity].

Experiments were conducted on rats. It was shown that long (80-100-day) hypokinesia led to the following significant disturbances of the nutritive circulation: reduction of the true capillary plexus, emptiness of the terminal arterioles and arteries, the direction of the terminal circulation chiefly through the arterio-venous anastomoses, avoiding the nutritive vessels. A tendency to reduction of the buffer bases in the venous blood and to the respiratory alkalosis in the arterial blood was noted. Hemorheological changes were insignificant.

Alkalosis, Respiratory↗
PubMed1977

[Effect of conditioning to altitude hypoxia on mesenteric microcirculation in rats].

A long-term training of rats to high-altitude hypoxia (in an altitude chamber at the height of 6500 m, 6 hours daily, for 30 to 40 days) results in a significant hyperemia of their intestinal wall and mesentery. The number of functioning capillaries of trained rats exceeded that of control animals several times, but the blood flow was slowed down in the dilated vessels and their structure was altered. Besides an obvious increase in blood rachemia in the arteries and veins, its rarefaction is observed in the capillaries. Definite hemorheological changes, probably associated with polycythemia, and an increased hematocrite index were noted.

Adaptation, Physiological↗
PubMed1976

[Microcirculatory changes in the cheek pouch mucosa of hamsters in the dynamics of experimental traumatic shock].

Acute experiments conducted on hamsters demonstrated significant disturbances of the microcirculation in the mucosa of the cheek pouch during a severe traumatic shock after a standardized mechanical injury of the hip. All the animals died in the course of the first 24 hours after this trauma. If the animals died not earlier than in one hour after the trauma the microcirculation changes were distinctly phasic in character; particularly there was seen a phase of temporary relative adaptation and stabilization of the peripheral circulation, invariably followed by the phase of decompensation, the terminal phase and death. In cases with a rapid lethal issue in the course of one hour no distinct phasic character of the microcirculation changes was observed, but there was a more or less rapid aggravation of all he indices. In difference from the majority of other investigators, no marked intravascular erythrocyte aggregation was seen by the authors in the experiments described.

Animals↗
PubMed1976

[Changes in mesenteric microcirculation in rats following repeated skin burns].

Acute experiments were conducted on rats; repeated extensive burn of a convalescent who formerly sustained the burn disease was better tolerated, led tono fatal outcome and was accompanied by moderate microcirculatory disturbances. The smae burn was accompanied in intact rats by a severe shock followed by death, intravascular aggregation of erythrocytes and significant microcirculatory disturbances leading to disturbance of tissue nutrition. It is supposed that the results obtained could serve as an indirect proof that toxemia played an important role in the genesis of intravascular aggregation of erythrocytes in burn shock.

Animals↗