[The effect of high-molecular compounds on the rheological properties of the blood and on the reactivity of the skeletal muscle vessels]. / Vliianie vysokomolekuliarnykh soedinenii na reologicheskie svoistva krovi i reaktivnost' sosudov skeletnoi myshtsy.

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. Dextran-20 thousand most favourably affects the blood viscosity whereas the least favourable one belongs to polyoxyethylene-20 thousand. The polymers with molecular mass about 500 thousand in small concentrations reduce the viscosity of the blood, in larger concentrations they enhance it increasing the erythrocytes aggregation.

[The effect of the dynamic component in the mechanical deformation of the vessels on the blood supply to the skeletal muscles]. / Vliianie dinamicheskogo komponenta mekhanicheskoi deformatsii sosudov na krovosnabzhenie skeletnykh myshts.

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. Isolated application of muscle vibration induced post-vibration hyperemia whereas the combination of the 8-24 Hz vibration with continuous distension of the muscle exerted no effect on the parameters of the post-elongation hyperemia.

[Blood supply of skeletal muscles in reactive hyperemia]. / Krovenapolnenie skeletnykh myshts pri reaktivnoi giperemii.

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. Papaverin interacts with the blood volume restoration and leads to insufficient restoration in the postocclusion period. This suggests that the postocclusion excessive restoration of the blood volume in muscle, as observed in control animals, can be due to an active vasodilatation of the capacitance portion of the intraorgan vascular bed.

[Nocigenic changes in the blood viscosity indices of rats]. / O notsigennykh izmeneniiakh pokazatelei viazkosti krovi u krys.

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. These changes are rather unfavourable for flowing properties of the blood. The changes of the blood rheological properties were reflex-based, the problem of compensatory shifts is discussed.

[Consistent component of spatial unevenness of capillary blood flow in a micromodule of skeletal muscle]. / Zakonomernaia sostavliaiushchaia prostranstvennoi neodnorodnosti kapilliarnogo krovotoka v mikromodule skeletnoi myshtsy.

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]. / Agregatsiia éritrotsitov v krovi, pomeshchennoi v makro- i mikrokiuvety.

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. Virtually similar results were obtained with blood of different animals and with different values of hematocrit. The data suggest a correlation between velocity of the aggregation and increase of the hematocrit value. Causes of discrepancies of the absolute values of parameters under study are discussed.

[Role of compression of the vessels of the gastrocnemius muscle in changes in its blood supply during stretching]. / Rol' sdavleniie sosudov ikronozhnoi myshtsy v izmeneniiakh ee krovosnabzheniia pri rastiazhenii.

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 3.0 ml . min-1 (100 r)-1. Decrease of the blood flow in stretching and the postelongation hyperemia could not be reproduced in external compression of the muscle equal to the balancing pressure at a given stretching. Only the external pressure 50 and 100 mm Hg decelerated the blood flow and developed a hyperemia even though a lesser one than the postelongation hyperemia. The effect of longitudinal muscle stretch on its vessels is not limited by their compression with the "intramuscular pressure".

[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.

[Hyperemia in capillaries of the gastrocnemius muscle following stretching]. / Giperemiia v kapilliarakh ikronozhnoi myshtsy posle ee rastiazheniia.

Microcine-tv-study of the isolated m. gastrocnemius' capillaries in 9 anesthetized cats determined the blood flow mean velocity as 0.73 +/- 0.12 mm/s with a considerable dispersion for 216 capillaries (variation coefficient = 120-160%). The temporal dispersion of velocities in a single capillary was insignificant (variation coefficient about 45%). Longitudinal stretch of the muscle for 1-2 cm decelerated the capillary blood flow up to its complete arrest. After 1-min stretch, the blood flow velocity increased by 0.30 +/- 0.06 mm/s in 148 capillaries; decreased by 0.22 +/- 0.07 mm/s in 35 capillaries and remained the same in 5 capillaries. Apart from this, 4 capillaries initially invisible, became apparent. Average data for capillaries corresponded to those of macro-experiments. Responses of individual capillaries seem to be unrelated to initial velocity of their location within the net, if only absolute values of velocities are to be analysed.

[Characteristic features of erythrocyte aggregation in different animals and in man]. / Osobennosti aggregatsii éritrotsitov u raznykh zhivotnykh i cheloveka.

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. The species features of the erythrocytes aggregation were altered by means of adding high--molecular polyoxyethylene to blood plasma. The data obtained gave evidence on species differences in the erythrocytes aggregation, specifics of cell membrane, differences in the latter's electrostatic charge.

[Effect of stretching of the cat gastrocnemius muscle on its tetany, postcontraction hyperemia and energy metabolism indices]. / Vliianie rastiazheniia ikronozhnoi myshtsy koshki na ee tetanusy, postkontraktsionnuiu giperemiiu i pokazateli énergeticheskogo metabolizma.

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. Additional posttetanic blood supply in the muscle, posttetanic alteration of the O2 consumption in it and the lactate/pyruvate ratio in longitudinal stretch do not differ from the analogous parameters in the initial--length muscle. The data obtained are in accordance with the metabolic theory of the hyperemia mechanisms but can hardly be explained from the standpoint of the histomechanical theory.

[Blood supply and oxygen consumption in the cat m. gastrocnemius during isometric tetanus in partial occlusion of the artery]. / Krovosnabzhenie i potreblenie kisloroda ikronozhnoi myshtsei koshki pri izometricheskom tetanuse v usloviiakh chastichnoi okkliuzii arterii.

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. A dependence of postcontraction hyperemia on the degree of blood flow restriction was found. No hyperemia occurs in a severe restriction. In a less severe restriction the hyperemia occurs and a stronger one than in the control. The post-load increase of O2 consumption in partial artery occlusion occurs both in absence and in presence of the postcontraction hyperemia, but in the latter case the increase of O2 consumption is related to the degree of postcontraction increase of the blood flow.

[Changes in blood flow after longitudinal stretching of the cat m. gastrocnemius]. / Ob izmeneniiakh krovotoka pri prodol'nykh rastiazheniiakh ikronozhnoi myshtsy koshki.

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. This reaction seems to be similar to hyperemia due to the artery occlusion in the muscle and is considerably weaker than the postcontraction increase in the blood flow. The character of intramuscular mechanical effects on the vessels during both the active contractions and the passive stretch, is discussed.

[Blood supply and oxygen consumption in cat musculus gastrocnemius during isometric tetanus and intra-arterial infusion of norepinephrine]. / Krovosnabzhenie i potreblenie kisloroda ikronozhnoi myshtsei koshki pri izometricheskom tetanuse v usloviiakh vnutriarterial'noi infuzii noradrenalina.

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. a. administration of noradrenaline, but the working hyperemia with concomitant changes of the metabolism indices becomes weaker than in control. A correlation of muscle blood supply changes with oxygen consumption changes was revealed whereas there was no correlation between changes of these indices and changes of oxygen extraction from the blood. A possibility of effects of the primary increase in blood flow occurring in hyperemia following the mechanical factor action, on the oxygen consumption is discussed as well as effect of willed decrease in blood flow within non-hypoxic range upon the oxidated metabolism.

[Effect of polyethylene oxides on erythrocyte aggregation]. / Vliianie poliétilenoksidov na agregatsiiu eritrotsitov.

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. The aggregation of erythrocytes is a reversible process. The decrease in polyethylene oxide concentration leads to decreasing aggregation effect. The mechanism of the effect of polymers on cell aggregation is discussed.