Cytoarchitecture of the smooth muscles and pericytes of rat cerebral blood vessels

1990 ◽  
Vol 73 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Issei Ushiwata ◽  
Tatsuo Ushiki
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Outer Diameter ◽  
Cerebral Blood Vessels ◽  
Fusiform Cell ◽  
Branching Points ◽  
Cytoplasmic Processes

✓ The three-dimensional cytoarchitecture of the smooth muscles and pericytes of rat cerebral blood vessels was studied by scanning electron microscopy after removing extracellular connective tissue matrices with the KOH-collagenase digestion method. The tunica media of major intracranial arteries such as the internal carotid, vertebral, basilar, and other cerebral arteries measuring more than 100 µm in outer diameter consisted of spindle-shaped smooth-muscle cells arranged circularly to the long axis of the vessel. Muscle cells at the branching points, however, showed a variety of shapes, sizes, and arrangements. As the vessel size decreased, smooth-muscle cells showed bi- or trifurcations at the cell poles. In the precapillary arterioles, smooth-muscle cells which had helically surrounded the endothelial tubes had bulging cell bodies with various cytoplasmic processes extending from the cell poles. Distinct specializations presumed to be sphincters were not found on the arteries or arterioles. Pericytes of the capillary had become extended along the vessel axis, having fusiform cell bodies with longitudinally oriented long cytoplasmic processes. Cells located periendothelially in the venules and veins were stellate in shape with many cytoplasmic processes which were interwoven to form complicated cellular networks around the endothelial tube.

The Neurovascular Unit: Focus on the Regulation of Arterial Smooth Muscle Cells

2020 ◽  
Vol 16 (5) ◽  
pp. 502-515 ◽  
Author(s):  
Patrícia Quelhas ◽  
Graça Baltazar ◽  
Elisa Cairrao
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Neurovascular Unit ◽  
Muscle Cells ◽  
Cerebral Blood Vessels ◽  
Mural Cells ◽  
Brain Pericytes ◽  
The Brain

The neurovascular unit is a physiological unit present in the brain, which is constituted by elements of the nervous system (neurons and astrocytes) and the vascular system (endothelial and mural cells). This unit is responsible for the homeostasis and regulation of cerebral blood flow. There are two major types of mural cells in the brain, pericytes and smooth muscle cells. At the arterial level, smooth muscle cells are the main components that wrap around the outside of cerebral blood vessels and the major contributors to basal tone maintenance, blood pressure and blood flow distribution. They present several mechanisms by which they regulate both vasodilation and vasoconstriction of cerebral blood vessels and their regulation becomes even more important in situations of injury or pathology. In this review, we discuss the main regulatory mechanisms of brain smooth muscle cells and their contributions to the correct brain homeostasis.

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.

scholarly journals Extrarenal angiomyolipoma in uterine cervix: rare presentation in unusual site

2019 ◽  
Vol 8 (1) ◽  
pp. 367
Author(s):  
Rashmi Monteiro ◽  
Shikha Sharma ◽  
Sonal Gupta ◽  
Indu Choudhary
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Uterine Cervix ◽  
Abdominal Mass ◽  
Muscle Cells ◽  
Renal Angiomyolipoma ◽  
Rare Presentation ◽  
Unusual Site ◽  
Hmb 45

Angiomyolipoma is a benign neoplasm composed of variable admixture of blood vessels, smooth muscle cells and adipose tissue. Cervical angiomyolipoma are extremely rare and to the best of our knowledge only five cases of angiomyolipoma in cervix have been reported in the literature till date. Authors are presenting a case of angiomyolipoma arising from the uterine cervix. 43 years old female presented with mass descending per vagina for 6 months. This case had no association with tuberous sclerosis. Microscopic examination showed an ill-defined polypoidal, non-encapsulated lesion covered by keratinized stratified epithelium. The lesion is made up of three components, predominantly by fascicles of spindle shaped cells, varying sized blood vessels and multiple foci of mature adipocytes with no evidence of atypia or increased mitotic activity. Smooth muscle component showed strong immunoreactivity to SMA and absence of elastic fibres in the blood vessels were confirmed by histochemistry. Non-vascular smooth muscle cells were negative for HMB-45 in contrast to renal and other extra-renal angiomyolipoma in which HMB-45 immunoreactivity in seen in these cells. To conclude, the differential diagnosis of lower abdominal mass and dysfunctional uterine bleeding should include the angiomyolipoma, even though the uterine cervix is an extremely rare location where they occur.

Characterization of [3H]nifedipine binding to intact vascular smooth muscle cells

1988 ◽  
Vol 254 (1) ◽  
pp. C45-C52 ◽  
Author(s):  
K. Sumimoto ◽  
M. Hirata ◽  
H. Kuriyama
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Binding Capacity ◽  
Specific Binding ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Scatchard Analysis ◽  
Intact Cells ◽  
Porcine Coronary Artery ◽  
Control Value

Specific binding of the dihydropyridine Ca2+ antagonist [3H]nifedipine to dispersed smooth muscle cells of the porcine coronary artery was investigated and the findings were compared with the binding to microsomes of smooth muscles. Specific binding to intact cells was saturable and reversible. The dissociation constant was 1.93 +/- 0.42 nM and the maximal binding capacity was 59.6 +/- 12.4 fmol/10(6) cells, as assessed by Scatchard analysis of the equilibrium binding at 25 degrees C. The Kd value with intact cells was slightly higher than that observed with microsomes. Specific binding of [3H]nifedipine to intact cells was completely displaced by unlabeled dihydropyridine derivatives. Among other Ca2+ antagonists, verapamil and d-cis-diltiazem partially and flunarizine completely inhibited the binding. In the case of microsomes, d-cis-diltiazem stimulated the binding of [3H]nifedipine. These results suggest that there may be multiple binding sites for different subclasses of Ca2+ antagonists. Polyvalent cations had no effect on the binding to intact cells. In the case of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA)-treated microsomes, the addition of CaCl2 and BaCl2 increased the Bmax, but the Kd value remained unchanged. MnCl2 and CdCl2 had stimulatory or inhibitory effects, depending on the concentrations, whereas LaCl3 had no effect. The effect of membrane depolarization on the binding was also examined. When the intact cells were incubated in high [K+]o solution for 60 min, the Kd was lowered to 1.4 nM from the control value of 2.0 nM, thereby indicating that [3H]nifedipine binds to Ca2+ channels, with a higher affinity, at depolarized states.

Molecular diversity of KVα- and β-subunit expression in canine gastrointestinal smooth muscles

1999 ◽  
Vol 277 (1) ◽  
pp. G127-G136 ◽  
Author(s):  
Anne Epperson ◽  
Helena P. Bonner ◽  
Sean M. Ward ◽  
William J. Hatton ◽  
Karri K. Bradley ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Pcr Analysis ◽  
Transcriptional Level ◽  
Gi Tract ◽  
Excitable Cells ◽  
Subunit Expression ◽  
Molecular Components

Voltage-activated K+(KV) channels play an important role in regulating the membrane potential in excitable cells. In gastrointestinal (GI) smooth muscles, these channels are particularly important in modulating spontaneous electrical activities. The purpose of this study was to identify the molecular components that may be responsible for the KV currents found in the canine GI tract. In this report, we have examined the qualitative expression of eighteen different KV channel genes in canine GI smooth muscle cells at the transcriptional level using RT-PCR analysis. Our results demonstrate the expression of KV1.4, KV1.5, KV1.6, KV2.2, and KV4.3 transcripts in all regions of the GI tract examined. Transcripts encoding KV1.2, KVβ1.1, and KVβ1.2 subunits were differentially expressed. KV1.1, KV1.3, KV2.1, KV3.1, KV3.2, KV3.4, KV4.1, KV4.2, and KVβ2.1 transcripts were not detected in any GI smooth muscle cells. We have also determined the protein expression for a subset of these KV channel subunits using specific antibodies by immunoblotting and immunohistochemistry. Immunoblotting and immunohistochemistry demonstrated that KV1.2, KV1.4, KV1.5, and KV2.2 are expressed at the protein level in GI tissues and smooth muscle cells. KV2.1 was not detected in any regions of the GI tract examined. These results suggest that the wide array of electrical activity found in different regions of the canine GI tract may be due in part to the differential expression of KV channel subunits.

Effects of prostaglandin F2α on membrane currents in rabbit middle cerebral arterial smooth muscle cells

2003 ◽  
Vol 284 (3) ◽  
pp. H1018-H1027 ◽  
Author(s):  
Nari Kim ◽  
Jin Han ◽  
Euiyong Kim
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Membrane Potentials ◽  
Delayed Rectifier ◽  
Direct Effects ◽  
Patch Clamp Technique ◽  
Arterial Smooth Muscle ◽  
Arterial Smooth Muscle Cells

Although PGF2αaffects contractility of vascular smooth muscles, no studies to date have addressed the electrophysiological mechanism of this effect. The purpose of our investigation was to examine the direct effects of PGF2α on membrane potentials, Ca2+-activated K+ (KCa) channels, delayed rectifier K+ (KV) channels, and L-type Ca2+channels with the patch-clamp technique in single rabbit middle cerebral arterial smooth muscle cells (SMCs). PGF2αsignificantly hyperpolarized membrane potentials and increased the amplitudes of total K+ currents. PGF2αincreased open-state probability but had little effect on the open and closed kinetics of KCa channels. PGF2αincreased the amplitudes of KV currents with a leftward shift of the activation and inactivation curves and a decrease in the activation time constant. PGF2α decreased the amplitudes of L-type Ca2+ currents without any significant change in threshold or apparent reversal potentials. This study provides the first finding that the direct effects of PGF2α on middle cerebral arterial SMCs, at least in part, could attenuate vasoconstriction.

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.

scholarly journals Differentiation of Smooth Muscle Cells in Human Blood Vessels as Defined by Smoothelin, a Novel Marker for the Contractile Phenotype

1997 ◽  
Vol 17 (4) ◽  
pp. 665-671 ◽  
Author(s):  
Frank T. L. van der Loop ◽  
Giulio Gabbiani ◽  
Gaby Kohnen ◽  
Frans C. S. Ramaekers ◽  
Guillaume J. J. M. van Eys
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Human Blood ◽  
Muscle Cells ◽  
Contractile Phenotype

scholarly journals Interstitial Cells: Regulators of Smooth Muscle Function

2014 ◽  
Vol 94 (3) ◽  
pp. 859-907 ◽  
Author(s):  
Kenton M. Sanders ◽  
Sean M. Ward ◽  
Sang Don Koh
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Motor Neurons ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Interstitial Cells ◽  
Pacemaker Activity ◽  
Molecular Features ◽  
Molecular Phenotypes ◽  
Cells Of Cajal

Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα+cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα+cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues.

scholarly journals Cyclic AMP-Rap1A signaling mediates cell surface translocation of microvascular smooth muscle α2C-adrenoceptors through the actin-binding protein filamin-2

2013 ◽  
Vol 305 (8) ◽  
pp. C829-C845 ◽  
Author(s):  
Hanaa K. B. Motawea ◽  
Selvi C. Jeyaraj ◽  
Ali H. Eid ◽  
Srabani Mitra ◽  
Nicholas T. Unger ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Plasma Membrane ◽  
Cyclic Amp ◽  
Cell Surface ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Muscle Cells ◽  
Small Gtpase ◽  
Actin Binding ◽  
Surface Translocation

The second messenger cyclic AMP (cAMP) plays a vital role in vascular physiology, including vasodilation of large blood vessels. We recently demonstrated cAMP activation of Epac-Rap1A and RhoA-Rho-associated kinase (ROCK)-F-actin signaling in arteriolar-derived smooth muscle cells increases expression and cell surface translocation of functional α2C-adrenoceptors (α2C-ARs) that mediate vasoconstriction in small blood vessels (arterioles). The Ras-related small GTPAse Rap1A increased expression of α2C-ARs and also increased translocation of perinuclear α2C-ARs to intracellular F-actin and to the plasma membrane. This study examined the mechanism of translocation to better understand the role of these newly discovered mediators of blood flow control, potentially activated in peripheral vascular disorders. We utilized a yeast two-hybrid screen with human microvascular smooth muscle cells (microVSM) cDNA library and the α2C-AR COOH terminus to identify a novel interaction with the actin cross-linker filamin-2. Yeast α-galactosidase assays, site-directed mutagenesis, and coimmunoprecipitation experiments in heterologous human embryonic kidney (HEK) 293 cells and in human microVSM demonstrated that α2C-ARs, but not α2A-AR subtype, interacted with filamin. In Rap1-stimulated human microVSM, α2C-ARs colocalized with filamin on intracellular filaments and at the plasma membrane. Small interfering RNA-mediated knockdown of filamin-2 inhibited Rap1-induced redistribution of α2C-ARs to the cell surface and inhibited receptor function. The studies suggest that cAMP-Rap1-Rho-ROCK signaling facilitates receptor translocation and function via phosphorylation of filamin-2 Ser2113. Together, these studies extend our previous findings to show that functional rescue of α2C-ARs is mediated through Rap1-filamin signaling. Perturbation of this signaling pathway may lead to alterations in α2C-AR trafficking and physiological function.

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