Organ and tissue-specific properties of the microcirculatory bed of the heart

The auricular and ventricular microcirculatory bed has been studied in persons of mature age, not suffering from any cardio-vascular diseases during their life. As a whole, 48 objects have been studied. The microcirculatory bed has been revealed in sections of the cardiac wall 70-100 mcm thick using silver nitrate impregnation after V. V. Kuprianov. Organ- and tissue-specific properties of the vascular microcirculatory bed are revealed in interrelations of the vessels and the structural elements of the cardiac wall (myocardium, and connective tissue structures), in position of nuclei of the endothelial cells of the capillary wall and in places of the capillary branchings. Principle differences in structure of the auricular and ventricular microcirculatory bed are demonstrated. The notion the organ- and tissue-specific properties of the microcirculatory bed vessels is discussed.     

Morphologic changes in the microcirculatory bed at stages of prolonged experimental fasting in animals

In 40 white male rats with body mass 180-200 g, by means of silver nitrate impregnation, morphological changes have been studied in the blood microcirculatory bed of the small intestine mesentery, spinal trapezoid muscle and eye ball conjunctiva at various stages of a prolonged fasting. With an increasing time of the experiment, a gradual undirected character of the changes in the microvessels is noted. After 3 days of fasting the changes in diameters of the microvessels, comparing to the control ones, have not any significant values in all the organs studied. After 6 days of fasting significant changes in diameters in all the links of the microcirculatory bed of the eye ball conjunctiva and in that of the spinal trapezoid muscle are observed. The microvascular changes are mostly pronounced on the 9th day of fasting. The maximal decrease of the microvessel diameters is noted in the eye ball conjunctiva, and the minimal--in the small intestine mesentery. The changes in the spinal trapezoid muscle are of intermediate character. The highest points of the structural lability gradient fall on the capillary and postcapillary-venular links of the blood microcirculatory bed.     

Structure and development of the microcirculatory bed of the pleural villi in man and animals

The structure of the microcirculatory bed in the pleural villi was studied by the method of impregnation with silver nitrate, after V.V. Kuprianov. In human and animal mediastinal pleura, the microcirculatory ways are regulated within polymerously repeated complexes--moduli. A characteristic feature of the pleural villi blood supply is the presence of capillary glomeruli with a vascular peduncle consisting of an arteriole and a venule. Four types of structure are revealed in the vascular peduncle consisting of an arteriole and a venule. Four types of structure are revealed in the vascular peduncle of the pleural villi. They were studied morphometrically. Correlation in the development of the villi microcirculatory bed and that of the vascular peduncle was stated. Participation of villous vessels in the regulation of fluid balance in the pleural cavity was discussed.     

Microcirculatory bed of the bulbar conjunctiva in 3- to 9-month-old fetuses

In 32 corpses of 3-9-month-old fetuses the diameter, length amount of the microcirculatory bed vessels and their wall thickness have been studied in different areas of the eye bulb conjunctiva by means of impregnation after Kuprianov. General morphofunctional vascular peculiarities have been revealed. They are connected with age and structure of the developing tissues in the eye bulb conjunctiva. Two stages of development have been defined: 3-6 and 7-9 months.     

The blood microcirculatory bed of the tunica muscularis of the human esophagus in postnatal ontogeny]

The analysis of morphological and morphometrical data of the muscular membrane and its blood microcirculatory bed has demonstrated that their development during the postnatal ontogenesis advances unevenly. An intensified growth and development of the muscular membrane morphological structures, including its blood microcirculatory bed occurs from 3 up to 30 years of life. Their maximal growth is noted from 12 up to 30 years of age. The stages of intensified development of the muscular membrane and its blood microcirculatory bed change into stages of retarded growth, where processes of involutive character preponderate. This is especially noticeable from 60 and more years of age. The stages noticed in the muscular membrane development and its blood microcirculatory bed are characterized both by general and topographical morphofunctional peculiarities specific for every stage of organogenesis.     

The microcirculatory bed of the human heart

Using a complex approach in studying microcirculatory bed of the human heart, possibilities of scanning electron microscopy of corrosive preparations, those of silver nitrate impregnation after V. V. Kuprianov are demonstrated. The silver nitrate impregnation makes it possible to study the wall structure of the microcirculatory pathways, to analyse arrangement of nuclei in the endothelial and muscle cells of the microcirculatory links, to reveal together with the vessels the surrounding tissues. Scanograms of the corrosive preparations of the arterioles demonstrate "circulatory strips", that are absent in the venular part. The relief of the luminal casts of the microcirculatory bed vessels in the human heart is presented as impresses of nuclei of the endothelial and smooth muscle cells. Peculiarities in form and distribution of these nuclei in various links of the microbed are demonstrated.     

Morphologic mechanisms of blood flow regulation in the hemomicrocirculatory system of the human heart during ontogenesis

Hearts of 220 human corpses, who had not any cardiovascular system disease during their life, have been distributed into age groups, beginning from fetuses up to old age. By means of injection, silver nitrate impregnation and scanning electron microscopy methods, applied to corrosive preparations, morphological mechanisms of the blood stream regulation in the hemomicrocirculatory bed of the human heart have been revealed in ontogenesis. The first group of the regulation mechanisms includes proper mechanisms inherent in the links of the microbed: spatial orientation of microvessels, precapillary sphincters, anastomoses between these vessels, sequence in arrangement of the endothelial cell nuclei, length, diameter and number of links in the microcirculatory bed. The second group embraces those mechanisms, that depend on structure of the myocardial wall, influencing the microcirculatory bed.     

Microarchitectonics and microtopography of blood vessels of the human rectum

By means of injecting the vessels with 0.2% solution of silver nitrate after Ranvier, solutions of Indian ink and gas soot, impregnation after V.V. Kuprianov, the blood vessels of the rectal wall have been studied. The material has been obtained from 50 corpses of persons of various age, not suffering from any diseases of the gastrointestinal tract. The structural organization of the microcirculatory tract has been studied layer-by-layer, at all levels by means of atraumatic lamination of the tunics. Terminal links of the microcirculatory bed form zonal functional complexes of microvessels specific for each part of the rectum. They regularly repeat in a certain tunic and owing to this the whole organization of the microcirculatory bed acquires features of a definite polymeric structure which consists of homonomic complexes of microvessels. Their regularity, as regards their topography and quantity, definitely differs in each tunic and layer of the rectal wall. Precapillary sphincters and arteriolovenular anastomoses are revealed; they perform an active regulation of blood circulation in the organ. Diameters of the microvessels and density of the microcirculatory network have some slight fluctuations (differences) in functionally poorly active tunics of the rectal wall--the serous and submucous, especially in its rectosigmoid part. Differences of these parameters are especially expressed within the limits of the rectal ampule and its mucous and muscular tunics.     

Morphogenesis of the eye of Siberian sturgeon

The most relevant changes in Acipenser baeri eye organization were detected between hatching and 5 days post hatch. At this age, the eye had an anterior chamber, lens, iris, choroid gland, scleral cartilage, cornea and a vitreous chamber lined by the retina (with two photoreceptors: rods and single cones).     

Topography of the borderline structures of the anterior portion of the inferior mediastinum and their vascularization

By means of silver nitrate impregnation after V. V. Kupriianov of blood vessels it has been revealed that the blood microcirculatory bed of the borderline structures in the anterior part of the inferior mediastinum, united by their topographical proximity and common sources of blood supply, are characterized by a high concentration of microvessels, arterioles, precapillaries, capillaries, postcapillaries and venules. In each structure investigated peculiar features of the blood microcirculatory bed organization are defined. Richness in vessels and their borderline position ensure potency of transudation and resorption of liquids from the inferior mediastinum in the cases, when the mediastinal part studied becomes the reservoir for pathological exudates (at traumas, at mediastinitis).     

Analysis of the structural parameters of the blood flow pathways in the microcirculatory system]

The reconstruction of the mesenterium microcirculatory bed was performed intravitally in albino rats and cats after biomicrophotograms. The number, length and caliber of arterioles, pericapillary arteriolec, capillaries, postcapillary venules and venules of the mesenterium were measured. According to these data summary indices of the cross section, surface and volume of the vessels of various functional subdivisions of the microcirculatory bed were calculated. The blood volume entering the microcirculatory system of the albino rat's mesenterium is distributed in the vessels as follows: 8,4% -- arterioles, 10,2% -- pericapillary arterioles, 41,9% -- capillaries, 22,1% -- postcapillary venules and 17,4% -- venules. Similar correlations were found in the cat. The working surface of capillaries is 60--70% of the working surface of all the vessels of the mesenterial microcirculatory system. The evidence of the functional variability of the microcirculatory bed geometry depending on the tissue needs in blood supply is presented.     

Effect of helium-neon laser on the microcirculation in blood vessels of the rat pia mater

The sensitivity of rat's microvessels of microcirculatory bed of brain's pia matter was studied by helium-neon laser radiation. Changes in the reactivity by the microscopy findings were studied on the 7, 30, 45, 60, 90th days of animals postnatal development. Laser radiation was used during 30 min. Local changes in all components of the microcirculatory bed were fixed. It is mentioned that in adult rat the expressiveness of arteriole's local widening reaction in the radiated place reduces, but the degree of the reduction is below or over the radiated place, on the contrary, increases. The arteriole diameter in 30-day old rats increases to 59% in comparison to the initial level, and 90th day old animals--to 16%. The degree of reaction's expressiveness depends upon the microvessel diameter and the animal's age.     

Development of the microcirculatory bed of the human tongue in the prenatal period

Morphofunctional regularities of formation and development of the blood microcirculatory bed in the human tongue have been studied in the prenatal period of morphogenesis. 119 human embryos and fetuses at the age of 5 weeks--9 months have been investigated. A complex of methods have been used: common histological (hematoxylin--eosin, after van Gieson and Mallory), injection of the lingual vessels with 20% suspension of Indian ink--gelatin, transmissive electron microscopy. General regularities of organogenesis, stages of the blood microcirculatory bed development and peculiarities of the process on formation of the primary protocapillary lingual blood bed are revealed. Regularities in structure of the terminal vascular constructions are studied for each structural element of the organ--mucosal membrane, muscles, glands, lingual tonsil. For these elements at the ultrastructural level certain features of the organic specificity in the structure of the blood microcirculatory bed links are determined.     

Development of the uterine microcirculatory bed in postnatal ontogeny

Age peculiarities of common structure of the microcirculatory pathways, specific volumes and amount of microvessels, zonal parameters of pericapillary microcirculation of metabolites, glycosamine glycans and glycoproteins contents, phosphatase and ATPase activity, collagen and elastic fibers of the microcirculatory bed vessels have been studied in 190 unchanged uteri, beginning from 36-week-old fetuses up to 35 years of age. The microcirculatory bed of myometrium during the period of postnatal ontogenesis investigated possesses a polymer-homonomous structural organization; its base make myoangiomas, including the terminal arteriole with precapillaries and collecting venule, that run from it. Similar structure of the myometrium microcirculatory pathways is already observed in fetuses of late antenatal period. In endometrium formed glanduloangionomas are revealed in the prepubertal age. Increase in glycosamine glycans contents is stated in the microvessel walls and in the uterine stroma during the process of its development. Compensatory-adaptive changes in the uterine microcirculatory bed are described during the newborn period up to the puberty. Functionally mature structures of the microcirculatory pathways in the submucosal and vascular layers of myometrium, endometrium and in the cervix uteri are found to be formed earlier than in other areas of the organ.     

Morphofunctional adjustments in the microvasculature of the conjunctiva of the human eye at different stages of the postnatal period of ontogenesis

By means of the biomicroscopy method under vital conditions, conjunctival microvessels in the eyeball have been investigated in 240 healthy boys 7-17 years of age at the state of rest and at the antiorthostatic action. The rearrangement of the conjunctival microcirculatory bed of the eyeball completes on the whole by 13-14 years of age and is characterized by transition from diffuse to a more refulate structure (the number of the main magistrals lessens, they become larger, the number of capillaries functioning simultaneously decreases, the role of the shunting blood stream becomes more important). With this process in ontogenesis, certain changes in reactivity of microvessels are connected. The quickest and the most adequate responses of the microvessels appear in the development by the time when the definitive composition of the conjunctival microcirculatory bed in the eyeball is formed. Since that time the microcirculatory system reaches its optimal level of functioning and all the processes are performed in the most economic regimen.     

Ultrastructural characteristics of the microcirculatory bed of the human adrenal cortex in prenatal ontogenesis

By means of transmissive electron microscopy the adrenals have been studied in 25 human embryos and fetuses at the age of 6-36 weeks. Certain stages have been revealed in formation of the adrenal cortex microcirculatory bed. In 6-7-week-old embryos (period of diffuse protocapillary bed) endothelial structure and mesenchymal cells, surrounding the adrenal anlage, resemble one another. A distinguished feature of the endothelium is regularly revealed desmosomes and large vacuoles, often found in cytoplasm of endotheliocytes. In 8-12-week-old fetuses (period when the organospecific microcirculatory bed is forming) sinusoid capillaries differentiate in the internal zone of the adrenal cortex; in endothelium fenestrae, "hatches", "locks" are revealed, the capillary basal membrane is formed. During subsequent time of the intrauterine development perfection of the microcirculatory pathways in the adrenals takes place, the arteriolar link of the subcapsular layer including. By the time of birth morphofunctional maturity of the microcirculatory bed in the adrenal cortex is noted.     

Morphofunctional characteristics of microcirculation in the skin of girls 5-17 years of age

In 261 girls year-to-year morphofunctional transformations of spatial composition of the skin microcirculatory bed have been studied at rest and after a dynamic local load. By means of biomicroscopy main regularities in development of the skin capillary network have been revealed in the nail torus in the postnatal ontogenesis. Formation of the microvessels reactivity during various age periods and maturation of mechanisms of the compensatory-adaptive reactions are connected with formation of the definitive composition of the microcirculatory bed, that in girls corresponds to 11-12 years. Qualitative transformations in the skin capillary network bring certain quantitative changes in the structural microcirculatory parameters--increasing diameter of microvessels and increasing density of functioning capillaries.     

Structural changes and hemodynamic relations in the microcirculatory bed of the mesentery of the white rat during the period of sexual maturation

Structural changes and hemodynamic relations have been studied in the microcirculatory bed of the white rat small intestine mesentery during sex maturation (from the 3d up to the 10th week of the postnatal development). All calculations are performed regarding the mesenteric segment limited with two intestinal arteries, which is considered as an elementary microvascular module. Complication of the microcirculatory bed construction takes place at the expense of increasing number (nearly five-fold) of microvessels in the segment and increase of the capillary network density. The hemodynamic factor plays a certain role for stimulating the process of the capillary growth. The definitive structure of the mesenteric microcirculatory bed is completed by the 7th week. The main rearrangement of the microcirculatory system during the developmental process from a simple arterio-venular loop up to a complex microcirculatory bed with a branching capillary network is performed within the limits of the mesenteric segment.     

Effect of chronic alcoholism on the state of the microcirculatory bed of the myocardium

Ultrastructure of myocardial capillaries of rats was studied in cases of chronic alcohol intoxication, experimental alcoholic cardiomyopathy (ACM) and its correction with antioxidants (vitamin E, dibunol). Alterations in the microcirculatory bed were similar in all groups of animals irrespective of disturbances in cardiomyocytes. Cardiomyocyte ultrastructure was improved after treatment with antioxidants, but capillary bed was the same as in untreated animals. High dibunol doses caused the onset of perivascular sclerosis. Disturbances in the microcirculatory bed are, probably, the first step in the determination of ACM pathogenesis and therapy of ACM must be directed at the correction of both alterations of cardiomyocytes and capillary bed.     

Microcirculatory bed of the pericardium under hypokinetic conditions]

The pericardium microcirculatory bed of rabbits was studied under conditions of hypokinesia of different duration. The state of hypokinesia was obtained by keeping the animals in small cages. The used methods were silver nitrate impregnation after Kuprijanov and injection of the vessels with the Parisian blue. Hypokinesia caused certain anatomical changes in all links of the microcirculatory bed. Disorders in the capillary-venular link were the first to appear. The alterations found should be considered as adaptational to effects of the extreme factor--hypokinesia.