In-vivo Studies on Selective Reduction of New-born Blood Vessels based on Ultrafast Laser Microsurgery

Amylin and adrenomedullin are two peptides structurally related to calcitonin gene-related peptide (CGRP). We studied the occurrence of amylin in trigeminal ganglia and cerebral blood vessels of the cat with immunocytochemistry and evaluated the role of amylin and adrenomedullin in the cerebral circulation by in vitro and in vivo pharmacology. Immunocytochemistry revealed that numerous nerve cell bodies in the trigeminal ganglion contained CGRP immunoreactivity (-ir); some of these also expressed amylin-ir but none adrenomedullin-ir. There were numerous nerve fibres surrounding cerebral blood vessels that contained CGRP-ir. Occasional fibres contained amylin-ir while we observed no adrenomedullin-ir in the vessel walls. With RT-PCR and Real-Time�PCR we revealed the presence of mRNA for calcitonin receptor-like receptor (CLRL) and receptor-activity-modifying proteins (RAMPs) in cat cerebral arteries. In vitro studies revealed that amylin, adrenomedullin, and CGRP relaxed ring segments of the cat middle cerebral artery. CGRP and amylin caused concentration-dependent relaxations at low concentrations of PGF2a-precontracted segment (with or without endothelium) whereas only at high concentration did adrenomedullin cause relaxation. CGRP8-37 blocked the CGRP and amylin induced relaxations in a parallel fashion. In vivo studies of amylin, adrenomedullin, and CGRP showed a brisk reproducible increase in local cerebral blood flow as examined using laser Doppler flowmetry applied to the cerebral cortex of the a-chloralose�anesthetized cat. The responses to amylin and CGRP were blocked by CGRP8-37. The studies suggest that there is a functional sub-set of amylin-containing trigeminal neurons which probably act via CGRP receptors.

Download Full-text

Mg2+–Ca2+ interaction in contractility of vascular smooth muscle: Mg2+ versus organic calcium channel blockers on myogenic tone and agonist-induced responsiveness of blood vessels

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y87-120 ◽

1987 ◽

Vol 65 (4) ◽

pp. 729-745 ◽

Cited By ~ 174

Author(s):

B. M. Altura ◽

B. T. Altura ◽

A. Carella ◽

A. Gebrewold ◽

T. Murakawa ◽

...

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Blood Vessels ◽

Divalent Cations ◽

Smooth Muscles ◽

In Vivo Studies ◽

Channel Blockers ◽

Arterial Blood

Contractility of all types of invertebrate and vertebrate muscle is dependent upon the actions and interactions of two divalent cations, viz., calcium (Ca2+) and magnesium (Mg2+) ions. The data presented and reviewed herein contrast the actions of several organic Ca2+ channel blockers with the natural, physiologic (inorganic) Ca2+ antagonist, Mg2+, on microvascular and macrovascular smooth muscles. Both direct in vivo studies on microscopic arteriolar and venular smooth muscles and in vitro studies on different types of blood vessels are presented. It is clear from the studies done so far that of all Ca2+ antagonists examined, only Mg2+ has the capability to inhibit myogenic, basal, and hormonal-induced vascular tone in all types of vascular smooth muscle. Data obtained with verapamil, nimopidine, nitrendipine, and nisoldipine on the microvasculature are suggestive of the probability that a heterogeneity of Ca2+ channels, and of Ca2+ binding sites, exists in different microvascular smooth muscles; although some appear to be voltage operated and others, receptor operated, they are probably heterogeneous in composition from one vascular region to another. Mg2+ appears to act on voltage-, receptor-, and leak-operated membrane channels in vascular smooth muscle. The organic Ca2+ channel blockers do not have this uniform capability; they demonstrate a selectivity when compared with Mg2+. Mg2+ appears to be a special kind of Ca2+ channel antagonist in vascular smooth muscle. At vascular membranes it can (i) block Ca2+ entry and exit, (ii) lower peripheral and cerebral vascular resistance, (iii) relieve cerebral, coronary, and peripheral vasospasm, and (iv) lower arterial blood pressure. At micromolar concentrations (i.e., 10–100 μM), Mg2+ can cause significant vasodilatation of intact arterioles and venules in all regional vasculatures so far examined. Although Mg2+ is three to five orders of magnitude less potent than the organic Ca2+ channel blockers, it possesses unique and potentially useful Ca2+ antagonistic properties.

Download Full-text

Circulation Index as a Quantitative Indicator of Angiogenesis in Chorioallantoic Membrane of Chicken Broilers

Contemporary Agriculture ◽

10.2478/contagri-2018-0023 ◽

2018 ◽

Vol 67 (2) ◽

pp. 164-170

Author(s):

Zoran Ružić ◽

Zdenko Kanački ◽

Dragan Žikić ◽

Gordana Ušćebrka ◽

Jovan Mirčeta

Keyword(s):

Embryonic Development ◽

Blood Vessels ◽

Chorioallantoic Membrane ◽

New Method ◽

In Vivo Studies ◽

Circulation Index ◽

Fast Method ◽

Angiogenic Response ◽

Embryonic Life

Summary Chorioallantoic membrane (CAM) is an extraembryonic membrane very frequently used for in vivo studies in various researches. Since researches require a fast method for quantifying the CAM angiogenic response, there is a need to develop a new precise and unbiased method of quantification of angiogenesis in CAM, which would be easy to perform and suitable for analysis of a large number of samples. The objective of this paper is to apply a new method of quantification of angiogenesis in investigation of the development of blood vessels in the CAM, in particular days of embryonic life considered essential for CAM development. The present research included 75 fertilized eggs of heavy hybrid Ross 308. CAM sampling for stereological analyses was in key phases of embryonic development, namely on the 12th, 15th and 19th day. The results of the present investigation show that the increase in embryonic age results in increase in circulation index, which is also an indicator of angiogenic processes developing in CAM. The lowest value of circulation index (0.1952) was recorded on the first sampling day (E12), while the highest value (0.2666) was recorded on the last sampling day (E19). This method may be applied in researching different factors which affect angiogenesis in CAM.

Download Full-text

Advanced in Molecular Mechanisms of Atherosclerosis: From Lipids to Inflammation

The Indonesian Biomedical Journal ◽

10.18585/inabj.v10i2.479 ◽

2018 ◽

Vol 10 (2) ◽

pp. 104-22 ◽

Cited By ~ 1

Author(s):

Anna Meiliana ◽

Nurrani Mustika Dewi ◽

Andi Wijaya

Keyword(s):

Vascular Disease ◽

Blood Vessels ◽

Molecular Mechanisms ◽

Vascular Dysfunction ◽

In Vivo Studies ◽

Disease States ◽

Fibrous Cap ◽

Plaque Disruption

BACKGROUND: Atherosclerosis is a leading cause of vascular disease worldwide. During the past several decades, landmark discoveries in the field of vascular biology have evolved our understanding of the biology of blood vessels and the pathobiology of local and systemic vascular disease states and have led to novel disease-modifying therapies for patients. This review is made to understand the molecular mechanism of atherosclerosis for these future therapies.CONTENT: Advances in molecular biology and -omics technologies have facilitated in vitro and in vivo studies which revealed that blood vessels regulate their own redox milieu, metabolism, mechanical environment, and phenotype, in part, through complex interactions between cellular components of the blood vessel wall and circulating factors. Dysregulation of these carefully orchestrated homeostatic interactions has also been implicated as the mechanism by which risk factors for cardiopulmonary vascular disease lead to vascular dysfunction, structural remodeling and, ultimately, adverse clinical events.SUMMARY: Atherosclerosis is a heterogeneous disease, despite a common initiating event of apoB-lipoproteins. Despite of acute thrombotic complications, an adequate resolution response is mounted, where efferocytosis prevents plaque necrosis and a reparative scarring response (the fibrous cap) prevents plaque disruption. However, a small percentage of developing atherosclerotic lesions cannot maintain an adequate resolution response, which leading to the formation of clinically dangerous plaques that can trigger acute lumenal thrombosis and tissue ischemiaand infarction.KEYWORDS: atherosclerosis, oxidative stress, inflammation, efferocytosis, foam cells, thrombosis

Download Full-text

Fibronectin and cell shape in vivo: studies on the endometrium during pregnancy.

The Journal of Cell Biology ◽

10.1083/jcb.94.3.597 ◽

1982 ◽

Vol 94 (3) ◽

pp. 597-606 ◽

Cited By ~ 47

Author(s):

F Grinnell ◽

J R Head ◽

J Hoffpauir

Keyword(s):

Basement Membrane ◽

Blood Vessels ◽

Cell Shape ◽

In Vivo Studies ◽

Trophoblast Invasion ◽

Phagocytic Cells ◽

Stromal Fibroblasts ◽

Decidual Tissue

The rat endometrium during pregnancy was used as a model system to study fibronectin in vivo. Fibronectin distribution on stromal fibroblasts, as determined by indirect immunofluorescence staining, was studied in relationship to cell shape during decidual transformation. Fibroblasts of the estrus endometrial stroma were elongated cells with a fibrillar pattern of fibronectin on their surfaces. During days 1-6 of pregnancy, as these elongated cells acquired a round morphology, fibronectin changed first to a patched distribution on the cells'a surfaces and then disappeared. The change in fibronectin was specific for the fibroblasts since over the same time period there was no decrease in fibronectin found associated with blood vessels or in the epithelial-stromal basement membrane. These results support the proposed relationship between cell surface fibronectin and cell shape that has been inferred from in vitro experiments. After implantation, fibronectin distribution was studied in relationship to the position of the conceptus. In the stroma proximal to the implanting conceptus, fibronectin was absent except around blood vessels, which may help explain how decidual tissue could act as a barrier to trophoblast invasion. Finally, fibronectin distribution was studied in the uterus after parturition. Debris in the uterine lumen was coated with fibronectin, which may be important in the rapid removal of this material by phagocytic cells. Also, fibronectin associated with the epithelial-stromal basement membrane was reorganized after reepithelialization had occurred.

Download Full-text

Selective ablation of angiogenic blood vessels based on ultrafast laser microsurgery

2007 Conference on Lasers and Electro-Optics - Pacific Rim ◽

10.1109/cleopr.2007.4391355 ◽

2007 ◽

Cited By ~ 1

Author(s):

Suk Yi Woo ◽

Ku Youn Baik ◽

Sae Chae Jeoung

Keyword(s):

Blood Vessels ◽

Ultrafast Laser ◽

Laser Microsurgery ◽

Selective Ablation

Download Full-text

in vivo 3D Morphology of Astrocyte—Vasculature Interactions in the Somatosensory Cortex: Implications for Neurovascular Coupling

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2010.204 ◽

2010 ◽

Vol 31 (3) ◽

pp. 795-806 ◽

Cited By ~ 90

Author(s):

Addason F H McCaslin ◽

Brenda R Chen ◽

Andrew J Radosevich ◽

Bruno Cauli ◽

Elizabeth M C Hillman

Keyword(s):

Blood Vessels ◽

Somatosensory Cortex ◽

Three Dimensional ◽

Neurovascular Coupling ◽

In Vivo Studies ◽

Two Photon Microscopy ◽

Two Photon ◽

Pial Arterioles ◽

Capillary Bed

Astrocytes are increasingly believed to play an important role in neurovascular coupling. Recent in vivo studies have shown that intracellular calcium levels in astrocytes correlate with reactivity in adjacent diving arterioles. However, the hemodynamic response to stimulation involves a complex orchestration of vessel dilations and constrictions that spread rapidly over wide distances. In this work, we study the three-dimensional cytoarchitecture of astrocytes and their interrelations with blood vessels down through layer IV of the mouse somatosensory cortex using in vivo two-photon microscopy. Vessels and astrocytes were visualized through intravenous dextran-conjugated fluorescein and cortically applied sulforhodamine 101 (SR101), respectively. In addition to exploring astrocyte density, vascular proximity, and microvascular density, we found that sheathing of subpial vessels by astrocyte processes was continuous along all capillaries, arterioles, and veins, comprising a highly interconnected pathway through which signals could feasibly be relayed over long distances via gap junctions. An inner SR101-positive sheath noted along pial and diving arterioles was determined to be nonastrocytic, and appears to represent selective SR101 staining of arterial endothelial cells. Our findings underscore the intimate relationship between astrocytes and all cortical blood vessels, and suggest that astrocytes could influence neurovascular regulation at a range of sites, including the capillary bed and pial arterioles.

Download Full-text