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Biomedical subjects

K A Shoshenko

Publications and source records attributed to K A Shoshenko.

16 recordsLinked to original sources
PubMed1992

[The reactions of the arterial and venous microvessels in hypertension and alloxan diabetes in rats].

In hereditary hypertension and chronic diabetes, the number of arterial capillary ends decreased at the arterial side and increased at the venous one in rats. The density of endotheliocyte nuclei decreased in the arteries and increased in the capillaries and veins in the mesentery of the HAHIS rats. The thickening of the venous vessels' walls was more obvious in the SHR rats. The findings suggest different velocities of the proliferative processes in the two types of vessels.

Animals↗
PubMed1991

[The oxygen diffusion coefficient in isolated skeletal muscle fibers].

The oxygen diffusion coefficients in isolated skeletal muscle fibres of Baikal seal and grayling, white rat, chicken were calculated on the basis of experimentally determined curve of dependence of the O2 consumption on pO2 and the radius of the fibres. In all the cases, the diffusion coefficient was smaller in the fibres than in water. The oxygen diffusion coefficient was increased during embryogenesis and postnatal period in chicken. The influence of different parameters of the oxygen transport and of properties of different fibres on the values of the oxygen diffusion coefficients, are discussed.

Animals↗
PubMed1991

[Oxygen tension in rat mixed skeletal muscle at a low diffusion coefficient].

Numerical simulation of the oxygen low diffusion coefficient (1.3.10-6 cm/sec) in a skeletal muscle with three types of fibres with different oxygen demands, has revealed: 1) an enlarged vascularisation of a fibre with high oxygen demand prevents the development of hypoxia because of shortening of the ways of oxygen diffusion from capillaries; 2) in a muscle with external layers consisting mainly of white fibres with low oxygen demand and deep layers of red fibres, the pO2 in the tissue and in the blood flowing from the layers, decrease with the depth.

Animals↗
PubMed1990

[Mitotic activity of the endothelium of different-diameter blood microvessels in the mesentery of Wistar rats].

The technique of intravascular autoradiography of 3H-thymidine labeled nuclei of microvessels endothelia was developed. The density difference of labeled cells in microvascular bed of mesentery was estimated. The maximal density of labelled nuclei was found in pre- and postcapillary vessels, and minimal--in capillaries and large arteries and veins of mesenteric bed. The number of labeled nuclei per vessel was found to be relatively constant. The density of labeled cells in 4-months old rats is less than that in 3 weeks-old ones.

Age Factors↗
PubMed1987

[Structural and functional organization of the microcirculatory bed of the frog and rat mesentery].

The arteriolar and venular network and the blood flow distribution were studied in mesenteric microvascular beds of frogs and rats. Some principles of spatial organization were established: an increase of branching coefficient, a decrease of branching asymmetry with the internal diameter of parent vessel progressively diminishing, the more frequent branching of venous tree including the fragment of a relatively greater volume. The values of geometrical and hemodynamical parameters were different in frogs and rats. Experimental dependence between pressure gradients and vessel radii was found to be exponential, thus being in agreement with prediction of a mathematical model based on physiologically significant criteria.

Animals↗
PubMed1986

[Oxygen consumption of the Baikal seal during unrestrained swimming in a pool and diving of different duration].

In 7 male Baikal seals (14-49 kg) spending 60-90% of the time under water, swimming unrestrained in the swimming pool, the average VO2 ranged from 8.6 +/- 7.01 ml (kg min)-1 for a 14-kg seal up to 4.8 +/- 2.22 ml (min kg)-1 (+ sigma) for adult 49-kg seal. A short forced diving (3-5 min) induced no change of the VO2 level because of stored oxygen. More prolonged diving (10-30 min) induced a 2-3-fold reduction of general VO2 and accumulation of a considerable O2-dept. During 3-5 min, 50-80% of this debt is covered in the 1st phase of recovery. The rest of the debt is covered during 10-40 min, depending on diving duration, body mass and, probably, oxidizing of metabolites of anaerobic exchange.

Animals↗
PubMed1983

[Architectonics of the arterial bed of the cerebral hemispheres in the normal rat and following a stay at an "altitude" of 5600 m].

Post mortem morphometric study of the arterial bed of the brain hemispheres in rats after 90-day stay at "the altitude" 5600 m revealed a noticeably larger diameter of arteries (D), a greater coefficient of their branching, lesser distances between branches (L), larger angles of branch deviation and a longer capillary bed. Calculations based on these data show that amount of arterial vessels and capillaries must increase in hypoxia, their length and linear blood flow velocity (V) must diminish, and the value of V/D2 and epsilon (LV/D2) characterizing the gradient of impetuous pressure and total losses of the impetuosity in the vascular bed must decrease.

Altitude↗
PubMed1978

[Blood supply in the arterial and venous bed of submaxillary muscle of frogs].

The velocity and morphometric parameters of blood flow in arterial and venous bifurcations of the trunks with diameter less than 85 microns in the frog m. submaxillaris were somewhat different as the angles of the braches II, the length of the vessels, and the bifurcation coefficient were greater in arterial part than in the venous bed. Due to this, the velocity in the arterioles was higher than in veins. According to the Pouiseulus equation, the pressure difference between arterioles and veins was 8.5 torr. About 44% of this difference was due to arterial vessels, about 36%--to the capillaries, pre- and post-capillaries, and about 20%--to the veins.

Animals↗
PubMed1977

[Architectonics of the arterial bed and blood flow in the lungs of frogs].

In morphometric studies of arteriolar branching of the frog lung with determination of the blood flow rate and its distribution, the diameter of the trunk was shown to lay between 16 and 350 mcm. The law of variation (in connection with the diameter range) and the specific features of interrelationship between some structural characteristics of the vascular branching were revealed. Analysis of the data obtained in vivo showed that the morphofunctional characteristics of the arteriolar branches in the frog lung corresponded to the theoretical "minimum work" model.

Animals↗
PubMed1976

[Blood flow distribution in the branches of frog mesentery arterial microvessels].

The blood flow distribution in 49 arterial branchings of the mesentery (R. temporaria) was investigated (D of the trunk = 25.7 + 0.0 mum). Linear rate was measured by the impulse digital chronometry of the intervals of the erythrocyte transit time. The geometric characteristics of the branching was determined in vivo, on photographs. An asymmetric structure of the investigated branching was shown; branch 1 had the inner initial cross-section which was 2.2 times greater than that of branch 2 and lesser turning angles (29 and 59 degrees). The blood flow in branch 1 was three times greater than the blood flow in branch 2; this was due to its greater inner initial cross-section and a higher linear rate. According to calculations, the blood flow resistance of the branch-turn was insignificant in the general blood flow resistance of branches; therefore the turning angle of the branches could not serve as an important regulator of the volume of the blood flowing in them. An experimentally revealed association between the blood flow in the branches, their radius and their turning angles is well described by equations of the "optimal" model of the vessel branching.

Animals↗
PubMedDate not supplied

[Cardiac minute volume and its pattern in Rana ridibunda frogs].

In frogs with an average body mass 56 g, the minute volume of the heart is equal to 4.5 ml/min X 100 g, which is approximately an order lower than in mammals with the same body mass. Pulmonary fraction constitutes 52% of the minute volume of the heart. The main bulk of systemic fraction of the minute volume of the heart (78%) passes to locomotor system and skin, whereas 19% of this volume are adressed to vegetative organs. This pattern of distribution significantly differs from that in mammals with a similar body mass, in which the vegetative and locomotor fractions are approximately equal. Differentiation in muscular blood supply was noted--there is a threefold difference in the volume of blood flow between gastrocnemius and submandibular muscles.

Animals↗