[The superposition of neural vasoconstrictor and local vasodilator effects on skeletal muscle vessels].

In anesthetised cats' m. gastrocnemius, under conditions of stabilised perfusion pressure, preservation of the sympathetic effect against the background of reactive and working hyperemia was shown in both rhythmic muscle contractions and in single tetani. The reactive hyperemia practically did not develop during sympathetic stimulation whereas the working one turned out to be a short-term one and considerably weakened as compared with the control.

[The effect of high-molecular compounds on the rheological properties of the blood and on the reactivity of the skeletal muscle vessels].

The administration of polymers into the vascular bed of the m. gastrocnemius and in vitro did not affect the postocclusion hyperemia but in changed the venous outflow from the muscle, the change having a phasic character. The effects of concentrations and molecular mass of the polymers on the blood rheological properties were more obvious in vitro.

[The effect of the dynamic component in the mechanical deformation of the vessels on the blood supply to the skeletal muscles].

Dynamic and static distension of the cat m. gastrocnemius by 10-20% of initial length induced similar hyperemia provided the same amplitude of the distension and a common impulse of passive strength are preserved. The post-elongation hyperemia did not depend on changes in the blood flow during distension or on increase in the number of dynamic components of the distension.

[Blood supply of skeletal muscles in reactive hyperemia].

In 18 anesthetized cats, 60-sec occlusion of the m. gastrocnemius artery entailed a decrease in the muscle blood supply by 15-20 ml of the blood volume in the vessels whereas the post-occlusion increase in the blood flow restored the blood volume with 45% excess. The intravascular accumulation of the blood exerting a moderating effect upon the venous return while preserving the increased arterial inflow, can be regarded as an automatic way of limiting the hemodynamic excitation due to the postocclusion shifts and involved in systemic circulation.

[Nocigenic changes in the blood viscosity indices of rats].

One-minute subcutaneous nociceptive stimulation increased arterial pressure by 15-20 mm Hg in Wistar rats. The 20-min. stimulation altered rheological properties of the blood: the hematocrit, the plasma viscosity and protein concentration, the erythrocyte aggregation velocity, the utmost tension of shift, and the viscosity of the blood standardized by hematocrit--all these parameters increased.

[Consistent component of spatial unevenness of capillary blood flow in a micromodule of skeletal muscle].

The filtration mathematical model of the skeletal muscle microvascular bed had predicted an unevenness of distribution of the blood velocity in capillaries. Experiments in cats corroborated existence of this unevenness and showed the latter to diminish under the effect of papaverine. The actuality of the model has been proved.

[Aggregation of erythrocytes placed in macro- and micro-cuvettes].

Changes of the intensity of light reflected or passing through cuvette with the blood specify the degree of blood aggregation. The parameters of light reflection by the surface of blood in macro-cuvette are compared with those of light passage through a thin micro-cuvette with preliminarily stirred blood. The latter technique enables a direct microscopy of the erythrocytes aggregation.

[Topography and hydrodynamic heterogeneity in the terminal bed of the vessels of the gastrocnemius muscle of the cat].

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.

[Role of compression of the vessels of the gastrocnemius muscle in changes in its blood supply during stretching].

In the m. gastrocnemius of anesthetized cats, the pressure of tissue resistance balancing was 5 mm Hg initially and developed a 7-fold increase in longitudinal stretch of the muscle by 10-20% when the total mechanical tension increased 20-fold (from 2400 to 47 662 H/m2) and the blood flow reduced from 5.0 to 3.

[Hyperemia in capillaries of the gastrocnemius muscle following stretching].

Microcine-tv-study of the isolated m. gastrocnemius' capillaries in 9 anesthetized cats determined the blood flow mean velocity as 0.73 +/- 0.

[Characteristic features of erythrocyte aggregation in different animals and in man].

The reversible erythrocytes aggregation is considered to be a basic microrheological process determining a number of microcirculation features. But the problem of the adaptive role of erythrocytes aggregation still needs elucidation. The markedness of erythrocytes aggregation was compared in mammals occupying different positions in the evolutionary systematics: in 62 animals of 10 species and in 25 healthy humans.

[Effect of stretching of the cat gastrocnemius muscle on its tetany, postcontraction hyperemia and energy metabolism indices].

Longitudinal stretch of the muscle in the range E = 0.11-0.17 (111-117% of the initial length) is followed by increase in passive strength and in mechanical displays of the 15-sec isometric Blood flow in the muscle vessels decreases at rest in the longitudinal stretching whereas O2 extraction from the blood increases; O2 consumption and ration of arterio-venous differences in the lactate and pyruvate concentration do not change.

[Changes in blood flow after longitudinal stretching of the cat m. gastrocnemius].

Longitudinal stretch of the cat m. gastrocnemius by 10-30% of initial length increased the passive strength and regularly decreased the blood flow, the latter being dependent not on the degree of deformation but on the value of passive tension. Postelongation hyperemia develops after the stretch.

[Blood supply and oxygen consumption in the cat m. gastrocnemius during isometric tetanus in partial occlusion of the artery].

O2 consumption in resting m. gastrocnemius decreases in restriction of blood supply due to partial artery occlusion. This occurs in accordance with the degree of blood flow restriction.

[Blood supply and oxygen consumption in cat musculus gastrocnemius during isometric tetanus and intra-arterial infusion of norepinephrine].

In anesthetized cats with maximal isometric tetanus induced by the n. ischiadicus stimulation, the initial oxygen consumption depended on the 2--fold reduction of initial blood flow, the anaerobic metabolism index remaining the same, at that. Stimulation of the nerve induces practically the same mechanical activity of the muscle in control and after i.

[Effect of polyethylene oxides on erythrocyte aggregation].

The effect of polyethylene oxide of different molecular weight on the aggregation of erythrocytes has been investigated. It was shown that the addition to blood of polymers with molecular weight of 600 and 1 000 weakens this aggregation, whereas the addition of those with molecular weights of 4 000 and 6 000 completely prevents it, simultaneously decreasing their osmotic resistance. Polyethylene oxide with molecular weight from 20 000 to 1 000 000 increase the aggregation of erythrocytes and do not affect their osmotic resistance.

[Relationship between metabolic and hemodynamic characteristics during isometric tetanus of the cat gastrocnemius muscle].

In anesthetized cats, the increase in duration of the isometric tetanic contraction of the m. gastrocnemius from 7 to 30 sec elicited a 4-fold increase in the muscular mechanical performance. During the postcontraction hyperemia, a 5-6-fold increase in the rate of lactic acid and inorganic phosphates removal into venous blood were opposed to only a 1.