scholarly journals Absence of Endothelium in Invertebrate Blood Vessels: Significance of Endothelium and Sympathetic Nerve/Medial Smooth Muscle in the Vertebrate Vascular System

2001 ◽  
Vol 87 (4) ◽  
pp. 253-260 ◽  
Author(s):  
Tatsuro Shigei ◽  
Hiromichi Tsuru ◽  
Naohisa Ishikawa ◽  
Koichi Yoshioka
Keyword(s):  
Smooth Muscle ◽  
Blood Vessels ◽  
Sympathetic Nerve ◽  
Vascular System

Endothelial and Smooth Muscle Cells as Antagonists in Vascular Fibrinoysis

1975 ◽  
Author(s):  
V. Noordhoek Hegt
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Vascular System ◽  
Muscle Cells ◽  
Vascular Wall ◽  
Vasa Vasorum ◽  
Slide Technique

Endothelial plasminogen activator activity in different types of human blood vessels obtained from fifty necropsies and thirty-five biopsies was detected and localized by means of plasminogen-rich fibrin slides. Great differences in endothelial activator activity were found along and across (vasa vasorum) the wall of the human vascular system.The same blood vessels were simultaneously investigated by a modified fibrin slide technique using plasminogen-free fibrin slides covered by plasmin to detect and localize inhibition of fibrinolysis in the vascular wall. The great variation in plasmin inhibition in different vessels revealed by this “fibrin slide sandwich technique” appeared to be closely associated with the localization and number of smooth muscle cells present in the walls of the vascular system. Strong plasmin inhibition was generally found at sites which showed no activator activity with the regular fibrin slide technique, while areas with a high endothelial fibrinolytic activity mostly revealed no inhibitory capacity.These results indicate that much of the variation in endothelial fibrinolytic activity on fibrin slides is due to inhibitory effects from the surrounding smooth muscle cells rather than to variability in the plasminogen activator content of the endothelium itself.

Connexins: Key Players in the Control of Vascular Plasticity and Function

2020 ◽  
Vol 100 (2) ◽  
pp. 525-572 ◽  
Author(s):  
Ulrich Pohl
Keyword(s):  
Smooth Muscle ◽  
Blood Vessels ◽  
Vascular System ◽  
Cell Reactivity ◽  
Cell Functions ◽  
Factor Type ◽  
Channel Dependent ◽  
Function Range ◽  
Independent Effects ◽  
And Function

Of the 21 members of the connexin family, 4 (Cx37, Cx40, Cx43, and Cx45) are expressed in the endothelium and/or smooth muscle of intact blood vessels to a variable and dynamically regulated degree. Full-length connexins oligomerize and form channel structures connecting the cytosol of adjacent cells (gap junctions) or the cytosol with the extracellular space (hemichannels). The different connexins vary mainly with regard to length and sequence of their cytosolic COOH-terminal tails. These COOH-terminal parts, which in the case of Cx43 are also translated as independent short isoforms, are involved in various cellular signaling cascades and regulate cell functions. This review focuses on channel-dependent and -independent effects of connexins in vascular cells. Channels play an essential role in coordinating and synchronizing endothelial and smooth muscle activity and in their interplay, in the control of vasomotor actions of blood vessels including endothelial cell reactivity to agonist stimulation, nitric oxide-dependent dilation, and endothelial-derived hyperpolarizing factor-type responses. Further channel-dependent and -independent roles of connexins in blood vessel function range from basic processes of vascular remodeling and angiogenesis to vascular permeability and interactions with leukocytes with the vessel wall. Together, these connexin functions constitute an often underestimated basis for the enormous plasticity of vascular morphology and function enabling the required dynamic adaptation of the vascular system to varying tissue demands.

Evidence for Presynaptic Parasympathetic Receptors on Nasal Blood Vessels

1982 ◽  
Vol 91 (2) ◽  
pp. 216-219 ◽  
Author(s):  
Richard T. Jackson
Keyword(s):  
Smooth Muscle ◽  
Blood Vessels ◽  
Muscarinic Receptor ◽  
Sympathetic Nerve ◽  
Neurotransmitter Release ◽  
Present Experiment ◽  
Presynaptic Receptors ◽  
Nerve Terminals ◽  
Norepinephrine Release ◽  
Nasal Blood Vessels

Noradrenergic synapses in the heart and several blood vessels have been shown to possess prejunctional receptors that modulate the release of norepinephrine from the synapse. The present experiment attempted to find evidence for presynaptic receptors for acetylcholine that modulated norepinephrine release. From the evidence obtained, it appears that the acetylcholine released from nasal parasympathetic fibers does not directly affect the smooth muscle of nasal blood vessels. Acetylcholine does, however, appear to inhibit the release of norepinephrine from nasal sympathetic nerve terminals. It appears that any nasal vasodilation produced by nasal parasympathetic fibers is caused by acetylcholine acting on an inhibitory, presynaptic, muscarinic receptor on the sympathetic nerve terminals. Acetylcholine would exert its control over nasal vessels by regulating the degree of sympathetic neurotransmitter release.

Microfluidics of blood in blood vessels stenosis

2016 ◽  
Vol 11 (2) ◽  
pp. 210-217 ◽  
Author(s):  
A.T. Akhmetov ◽  
A.A. Valiev ◽  
A.A. Rakhimov ◽  
S.P. Sametov ◽  
R.R. Habibullina
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Hydraulic Resistance ◽  
Microfluidic Device ◽  
Human Body ◽  
Vascular System ◽  
Hydrodynamic Conditions ◽  
Microstructure Change ◽  
Healthy Part

It is mentioned in the paper that hydrodynamic conditions of a flow in blood vessels with the stenosis are abnormal in relation to the total hemodynamic conditions of blood flow in a vascular system of a human body. A microfluidic device developed with a stepped narrowing for studying of the blood flow at abnormal conditions allowed to reveal blood structure in microchannels simulating the stenosis. Microstructure change is observed during the flow of both native and diluted blood through the narrowing. The study of hemorheological properties allowed us to determine an increasing contribution of the hydraulic resistance of the healthy part of the vessel during the stenosis formation.

Effect of all-trans retinoic acid and pentagalloyl glucose on smooth muscle cell elastogenesis

2021 ◽  
pp. 1-13
Author(s):  
Kaveh Sanaei ◽  
Sydney Plotner ◽  
Anson Oommen Jacob ◽  
Jaime Ramirez-Vick ◽  
Narendra Vyavahare ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Retinoic Acid ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Muscle Cells ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Tissue Engineered Blood Vessels ◽  
Pentagalloyl Glucose ◽  
Vitamin A Derivative

BACKGROUND: The main objective of tissue engineering is to fabricate a tissue construct that mimics native tissue both biologically and mechanically. A recurring problem for tissue-engineered blood vessels (TEBV) is deficient elastogenesis from seeded smooth muscle cells. Elastin is an integral mechanical component in blood vessels, allowing elastic deformation and retraction in response to the shear and pulsatile forces of the cardiac system. OBJECTIVE: The goal of this research is to assess the effect of the vitamin A derivative all-trans retinoic acid (RA) and polyphenol pentagalloyl glucose (PGG) on the expression of elastin in human aortic smooth muscle cells (hASMC). METHODS: A polycaprolactone (PCL) and the gelatin polymer composite was electrospun and doped with RA and PGG. The scaffolds were subsequently seeded with hASMCs and incubated for five weeks. The resulting tissue-engineered constructs were evaluated using qPCR and Fastin assay for their elastin expression and deposition. RESULTS: All treatments showed an increased elastin expression compared to the control, with PGG treatments showing a significant increase in gene expression and elastin deposition.

Differential Expression of Melanocytic Markers in Myoid, Lipomatous, and Vascular Components of Renal Angiomyolipomas

2007 ◽  
Vol 131 (1) ◽  
pp. 122-125 ◽  
Author(s):  
Andres A. Roma ◽  
Cristina Magi-Galluzzi ◽  
Ming Zhou
Keyword(s):  
Smooth Muscle ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Differential Expression ◽  
Tumor Cells ◽  
Tissue Microarray ◽  
Expression Patterns ◽  
Renal Angiomyolipoma ◽  
Melanocytic Lesions ◽  
Hmb 45

Abstract Context.—Renal angiomyolipoma is a tumor composed of varying amounts of fat, smooth muscle, and blood vessels. Characteristically, tumor cells express melanocytic markers such as HMB-45 and Melan-A. Recently, several other markers have been described as having excellent diagnostic sensitivity in cutaneous melanocytic lesions. Objectives.—To compare the sensitivities of 5 melanocytic markers in renal angiomyolipoma and to study the expression patterns of these markers in the 3 different components of angiomyolipoma. Design.—A tissue microarray of 20 renal angiomyolipomas was constructed. For each case, 3 cores containing fat, blood vessels, and smooth muscle were taken. The tissue microarray was then stained for HMB-45, Melan-A, tyrosinase, NK1-C3, and CD117. Results.—HMB-45 was positive in 95%, Melan-A in 85%, NK1-C3 in 70%, tyrosinase in 50%, and CD117 in 40% of the cases. All (20/20) were positive for HMB-45 and Melan-A combined. These 5 markers had different sensitivities in the 3 components. HMB-45 was positive in 90%, 85%, and 80% of fat, smooth muscle, and blood vessel components, respectively; Melan-A in 70%, 60%, and 40%; NK1-C3 in 55%, 55%, and 45%; tyrosinase in 30%, 40%, and 10%; and CD117 in 20%, 40%, and 10%, respectively, of these 3 components. Conclusions.—HMB-45 and Melan-A combined were positive in 100% of the renal angiomyolipomas. We recommend the use of these 2 markers in the workup of this entity, including those with predominantly 1 component. Other melanocytic markers are of limited use. A tissue block comprising predominantly fat or smooth muscle components should be used when performing melanocytic marker immunostain.

Memoirs: Notes on the Structure and the Development of the Elephant's Placenta

1905 ◽  
Vol s2-49 (193) ◽  
pp. 1-38
Author(s):  
RICHARD ASSHETON ◽  
THOMAS G. STEVENS
Keyword(s):  
Blood Vessels ◽  
Vascular System ◽  
Single Layer ◽  
Blood Stream ◽  
Maternal Blood ◽  
Full Term ◽  
Maternal Tissue ◽  
Term Placenta ◽  
Uterine Mucosa ◽  
Foetal Blood

1. The full-term after-birth of the elephant consists of a chorion from which spring many much-branched villi, which spread out in all directions into plate-like branches. These end in (a) proximal foliaceous terminations, in which the fœtal blood vessels ramify, which interlace with a complicated system of much larger blood channels filled with maternal blood, having well-defined but non-nucleated walls; (b) more distal lobate terminations, which are covered by a wellmarked columnar or cubical epithelium -- presumably the trophoblast -- which are partly embedded in a kind of coagulum or detritus, and partly appear to hang loosely in irregular blood spaces without walls ; (c) the stems of still more prolonged villi, which have been torn off and probably left embedded in the walls of the uterus; (d) a few torn ends of blood-vessels. 2. The main trunks of the villi and their foliaceous terminations are everywhere separated from the maternal bloodchannels by a syncytial layer, which is continuous with the epithelium covering the lobate terminations, and is presumably trophoblastic. 3. The half-term placenta originally examined by Owen in 1850 shows, in its more central region, characters which are essentially similar to those of the full-term specimen, and goes far to prove the existence of longer villi which penetrate deeply into the uterine mucosa. The lateral areas of the zonary belt exhibit many most interesting previous conditions. We are able to see in these the simple terminations of the foetal villi covered with a single layer of trophoblast separated from the uterine tissues by a layer of matei'ial partly maternal and partly of foetal origin. There is no process of growth round existing maternal capillaries to form an angio-plasmode, nor apparently any phagocytic action on the part of the trophoblast. The vascularisation of the after-birth is effected by the invasion of the trophoblast by extravasated maternal blood, which flows at first in intercellular and intervillous passages which form the larger channels of the after-birth maternal vascular system, and then makes its way along intra-cellular or intrasyncytial canals through a plasmodium produced by the breaking down of the trophoblast of two adjoining villi. We think the evidence is in favour of considering the corpuscles floating in this invading stream, which contains no red non-nucleated corpuscles in its more advanced portions, to be of maternal rather than trophoblastic origin. 4. The tissues of the full-term placenta contain pigment granules, which are deposited chiefly in the syncytial layer. This we regard as an excretory product; it is almost quite absent from the tissues of the half-term specimen. Leucocytes, either of maternal or foetal origin, seem to be concerned in the transference of this pigment into the maternal blood stream. 5. The subcircular bodies of Owen we find as described by him and Turner, though we note the presence of minute villi on their outer surface. 6. We confirm the opinion of previous writers that the zonary band in part is a "deciduous" form of placenta, although there is not much maternal tissue except the blood. It is not correct to speak of the after-birth being composed of a "much hypertrophied mncosa layer of the uterus." 7. The placenta of the elephant shows by its long villi, which tend to remain embedded in the uterus wall, a resemblance to the condition found in the Sirenia; by the villous patches at the poles and other villi which come out from the uterus, either with or without their trophoblastic covering, but with no maternal cells attached, a resemblance to the ungulata vera of the Perissodactyl type ; by the invasion of the trophoblast--if such it is--by the maternal blood stream, a resemblance to the Discoplacental type, although the actual manner by which this invasion occnrs would seem to be--so far as our very limited material affords us opportunity of observation--unlike anything hitherto described.1 8. The resemblance, at first sight obvious enough to the zonary placenta of the carnivora, is superficial. The elephant's placenta differs from that of the carnivora in (a) consisting of three areas of attachment instead of one, two of which, are wholly in the non-deciduous type, the other partly deciduous, partly non-deciduous. (b) There is nothing formed comparable to an angio-plasmode. (c) The maternal capillaries do not directly become the maternal vessels of the after-birth.

EVALUATION OF THE VESSEL AGE BY APPLYING THE ACCELERATION PLETHYSMOGRAM ANALYSIS

2021 ◽  
pp. 61-67
Author(s):  
Елизавета Александровна Молчанова ◽  
Петр Вячеславович Лужнов
Keyword(s):  
Blood Vessels ◽  
Pulse Wave ◽  
Vascular System ◽  
Vascular Wall ◽  
Second Derivative ◽  
Contour Analysis ◽  
Physiological Factors ◽  
Vascular Age ◽  
Relationship Of ◽  
The Relationship

В работе приведены понятия жесткости, эластичности и тонуса сосудов, а также же их взаимосвязь с общим состоянием сосудистой стенки. Описан индекс, объединяющий влияние вышеперечисленных факторов на состояние сосудистой системы и дающий представление о возрасте сосудов пациента, а также показана связь этого индекса с возрастом человека. Представлен обзор способов определения возраста сосудов с помощью контурного анализа пульсовой волны. Среди предложенных способов был выделен подход на основе контурного анализа сигнала пульсовой волны, а также ее второй производной. В данном исследовании проводилась разработка алгоритма расчета показателя возраста сосудов (VA), базирующаяся на анализе сигнала и его второй производной. При этом особое внимание уделялось физической интерпретации параметров, входящих в состав расчетной формулы. С помощью представленного алгоритма в группе из трех испытуемых был определен сосудистый возраст. Из анализа полученных результатов было выявлено влияние физиологических факторов на значение возраста сосудов. Предложены методики, позволяющие исключить влияние этих факторов на значения показателя VA и тем самым получить более точные результаты. Также представлены стратегии дальнейшего развития исследований в этом направлении In The paper presents the concepts of rigidity, elasticity and tone of blood vessels, as well as their relationship with the general state of the vascular wall. An index is described that combines the influence of the above factors on the state of the vascular system and gives an idea of the age of the patient's vessels, and also shows the relationship of this index with the age of a person. An overview of the methods for determining the age of blood vessels using the contour analysis of the pulse wave is presented. Among the proposed methods, an approach based on the contour analysis of the pulse wave signal, as well as its second derivative, was singled out. In this study, an algorithm was developed for calculating the indicator of vascular age (VA), based on the analysis of the signal and its second derivative. In this case, special attention was paid to the physical interpretation of the parameters included in the calculation formula. Using the presented algorithm, vascular age was determined in a group of three subjects. From the analysis of the results obtained, the influence of physiological factors on the value of the age of the vessels was revealed. Methods are proposed that allow to exclude the influence of these factors on the values of the VA indicator and thereby obtain more accurate results. Also presented are strategies for the further development of research in this direction

Digital motion analysis as a tool for analysing the shape and performance of the circulatory system in transparent animals

2000 ◽  
Vol 203 (11) ◽  
pp. 1659-1669 ◽  
Author(s):  
T. Schwerte ◽  
B. Pelster
Keyword(s):  
Blood Vessels ◽  
Fluorescent Probe ◽  
Motion Analysis ◽  
Vascular System ◽  
Circulatory System ◽  
Cardiac Activity ◽  
Video Frame ◽  
Peripheral Blood Flow ◽  
Gray Scale ◽  
And Performance

The analysis of perfusion parameters using the frame-to-frame technique and the observation of small blood vessels in transparent animals using video microscopy can be tedious and very difficult because of the poor contrast of the images. Injection of a fluorescent probe (fluorescein isothiocynate, FITC) bound to a high-molecular-mass dextran improved the visibility of blood vessels, but the gray-scale histogram showed blurring at the edges of the vessels. Furthermore, injection of the fluorescent probe into the ventricle of small zebrafish (Danio rerio) embryos (body mass approximately 1 mg) often resulted in reduced cardiac activity. Digital motion analysis, however, proved to be a very effective tool for analysing the shape and performance of the circulatory system in transparent animals and tissues. By subtracting the two fields of a video frame (the odd and the even frame), any movement that occurred within the 20 ms necessary for the acquisition of one field could be visualised. The length of the shifting vector generated by this subtraction, represented a direct measure of the velocity of a moving particle, i.e. an erythrocyte in the vascular system. By accumulating shifting vectors generated from several consecutive video frames, a complete trace of the routes over which erythrocytes moved could be obtained. Thus, a cast of the vascular system, except for those tiny vessels that are not entered by erythrocytes, could be obtained. Because the gray-scale value of any given pixel or any given group of pixels increased with the number of erythrocytes passing it, digital motion analysis could also be used to visualise the distribution of blood cells in transparent tissues. This method was used to describe the development of the peripheral vascular system in zebrafish larvae up to 8 days post-fertilisation. At this stage, food intake resulted in a clear redistribution of blood between muscle tissue and the gut, and alpha-adrenergic control of peripheral blood flow was established.

Growth regulation of the vascular system: evidence for a metabolic hypothesis

1990 ◽  
Vol 259 (3) ◽  
pp. R393-R404 ◽  
Author(s):  
T. H. Adair ◽  
W. J. Gay ◽  
J. P. Montani
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Growth Regulation ◽  
Vascular System ◽  
Major Influence ◽  
Control Element ◽  
Hypoxic Conditions ◽  
Control Growth ◽  
Vessel Growth ◽  
Tissue Cells

Prolonged imbalances between the perfusion capabilities of the blood vessels and the metabolic requirements of the tissue cells often lead to modification of the vasculature to satisfy the tissue needs. This homeostatic response appears to be bidirectional, since the vascularity of a tissue can increase or decrease in parallel with primary changes in metabolic rate. The factors that mediate the responses are not well understood, but oxygen has been implicated as a major control element, since vessel growth increases during hypoxic conditions and decreases during hyperoxic conditions. The following feedback control hypothesis may apply to many different physiological situations. Decreased oxygenation causes the tissues to become hypoxic, and this initiates a variety of signals that lead to the growth of blood vessels. The increase in vascularity promotes oxygen delivery to the tissue cells by decreasing diffusion distances, increasing capillary surface area, and increasing the maximum rate of blood flow. When the tissues receive adequate amounts of oxygen even during periods of peak activity, the intermediate effectors return to normal levels, and this negative signal, in turn, stops the further development of the vasculature. Although the effector mechanisms of the hypoxic stimulus are still being investigated, adenosine, which is produced in hypoxic tissues, appears to mediate hypoxia-induced increases in vascularity in some instances. Roles for fibroblast growth factor as well as mechanical factors associated with vasodilation and increased blood flow are postulated. Although blood vessel growth is a multifactorial process, a major influence in its regulation appears to be metabolic need. If this view is correct, it may be found that many of the quantitatively significant factors that control growth in a given vasculature are themselves modulated or controlled by metabolic signals reflecting the nutritional status of the tissues which that vasculature supplies.

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