Condition of the microcirculatory bed of the bulbar conjunctiva in physiological and pathological pregnancies

By means of biomicroscopic method the bulbar conjunctiva in 150 women (18-35 years of age) have been examined. Of them: 30 healthy women make the control group; the second group includes 60 healthy women at their first and second half of pregnancy; the third group includes 60 women with pregnancy developing against the background of noncomplicated insulin-dependent diabetus mellitus during their first and second half of pregnancy. In the healthy women there are not any significant changes in most of the parameters of the microcirculatory bed during the first half of their pregnancy, and in the second half of their pregnancy a great density of the blood vascular bed is determined. Diameters of all vessels in the hemomicrocirculatory bed are significantly increased, as compared to those in the control group. In the women suffering from diabetus mellitus, during the first half of pregnancy certain changes in the picture of the vascular network is observed, as well as an increased convolution. uneveness in distribution of blood vessels; in the second half of their pregnancy a pronounced deformity of the vacular network is observed, decreasing diameter of afferent vessels and an essential dilatation of postcapillaries and venules are registered. Certain signs of aggregation of blood formed elements is noted.     

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.     

Regulatory characteristics of the different components of the mesenteric microcirculatory bed in rats

Heterogeneous tonic reactions of the different parts of the mesentery microcirculatory bed to intravenous infusions of noradrenaline and their cessation were revealed. It is assumed that venules play a more important role in the organization of blood circulation in the capillaries and arteriolo-venular anastomoses than arterioles.     

Effect of lead and tetraethyl lead poisoning on the microcirculatory bed of the conjunctiva of the eye

The ultrastructure of the bulbar conjunctiva bioptates have been studied in 12 persons suffering from lead intoxication (saturnism), 2-from tetraethyl-lead (TEL) intoxication and 3-are practically healthy persons; they make the control group. In all the patients manifested disturbances in the microcirculatory bed of the bulbar conjunctiva are revealed, the general character being identical at saturnism and TEL-intoxication. The main changes are observed in the wall of the blood microvessels: destruction of the endothelial lining up to revealing the basal membrane with adhesion of the blood formed elements and their diapedesis. This results in disorders of vascular permeability, in edema of the perivascular space and in appearance of cells and cellular detritus in it. An essential role in morphogenesis of the vascular disturbances produced by intoxication play certain rheological imparements: sludge-syndrome and microthrombosis. They produce certain distrophic changes.     

Functional NOS 1 in the rat mesenteric arterial bed

Previously we have demonstrated functional nitric oxide synthase (NOS) 1 in large arteries. Because resistance arteries largely determine blood pressure, this study examined whether functional NOS 1 also exists in resistance arteries. Phenylephrine (PE) contraction was measured in the absence and presence of the NOS 1 inhibitor N(5)-(1-imino-3-butenyl)-L-ornithine (VNIO) in isolated mesenteric resistance arteries (endothelium intact and denuded) from Sprague-Dawley rats. For NOS 1 activity and expression, the mesenteric arterial bed was separated into cytosolic and particulate fractions. NOS activity was assayed by measuring the conversion of [(3)H]arginine to [(3)H]citrulline inhibited by a nonselective NOS inhibitor or VNIO. VNIO increased PE sensitivity in endothelium-intact and -denuded arteries. In cytosolic and particulate fractions of the arterial bed, approximately 40% of NOS activity was inhibited by VNIO. Immunoprecipitation and Western blot analysis revealed two NOS 1 immunoreactive bands. One band corresponded to the rat brain isoform, whereas the second was of a slightly lower molecular mass. The cytosolic fraction contained both isoforms; however, the particulate fraction had only the lower molecular mass form. These studies demonstrate the existence of functional NOS 1 in resistance arteries.     

Systemic and organic changes in the microcirculatory bed in experimental dehydration of the body

Among systemic mechanisms of microvascular reactivity of the musculus spinotrapezius, pancreas and small intestine mesentery at dehydration, a special role play the changes directed to maintenance of harmony between the capacity of the blood bed and volume of the circulatory blood, morpho-functional factors on regulation of hemodynamics, as well as mechanism of liquor resource++ elimination from the blood bed. The organic peculiarities of the microvascular reactivity at dehydration are determined by topic and quantitative character of their changes.     

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.     

Anatomical basis for cerebrospinal fluid resorption by the structures of the microcirculatory bed in the human spinal dura mater

By means of noninjective methods of investigation a specific capillary network of a sinusoidal type, peculiar arteriolovenular anastomoses, additional reservoirs in the area of postcapillaries and venules described in the microcirculatory bed of the spinal dura mater. The peculiarity of this vascular bed is thought by the authors to be connected with liquor resorption from the subdural space of the spinal cord.     

Endothelium-dependent relaxations to histamine in the rat common carotid, renal and cranial mesenteric artery

The effect of histamine on the isolated rat common carotid, renal and cranial mesenteric arteries was examined. Histamine (10(-8)-10(-4) M) caused concentration-dependent relaxations of the arteries during contractions induced with phenylephrine (10(-8)-10(-7) M). Removal of the vascular endothelium inhibited the histamine-induced relaxations. Pyrilamine (6 X 10(-6) M), but not metiamide (10(-6) M), abolished the relaxant effect of histamine. Moreover, pyrilamine (6 X 10(-6) M) did not affect endothelium-dependent relaxations of the arteries produced with acetylcholine. These results indicate that histamine causes endothelium-dependent relaxations of the rat peripheral large conduit arteries, which appeared to be mediated via H1-histaminergic receptors.     

Functional and morphological changes in the kidneys in acute embologenic arterial occlusion of the extremities

The results of biochemical, radioisotope and morphological investigations of dog kidneys in experimental acute occlusion of hind limb arteries during ischemia and in postischemic periods are reviewed. Morphological and functional changes in the kidneys occur in ischemia. Blood flow recovery in the extremities aggravates these changes leading in 12-hour ischemia to acute renal failure.     

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.     

Functional and morphological changes in the gastrointestinal tract in experimental burn shock

The gastrointestinal tract was examined in 56 dogs during burn shock (over 72 hours after injury). It was shown that burn shock entails acute catarrhal or erosive gastroenterocolitis at the basis of which there lie microcirculatory disorders and the decreased content of the "protective mucus" (glycosaminoglycans) in the integumentary epithelium. Combined therapy that normalizes primarily the circulatory channel and output of glycosaminoglycans leads to the reduction of the intensity of the above-mentioned processes in the gastrointestinal wall and prevents, to an appreciable degree, the development of erosive and ulcerous lesions.