The KCa3.1 Channel in Endothelial Cells as New Target for an EDHF-Based Control of Vascular Tone: From Structure to Regulation and Pharmacological Properties

2008 ◽  
pp. 357-374
Author(s):  
Umberto Banderali ◽  
Line Garneau ◽  
Manuel Simoes ◽  
Hélène Klein ◽  
Rémy Sauvé
Keyword(s):  
Endothelial Cells ◽  
Vascular Tone ◽  
Pharmacological Properties

Adenosine enhances nitric oxide production by vascular endothelial cells

1995 ◽  
Vol 269 (2) ◽  
pp. C519-C523 ◽  
Author(s):  
J. M. Li ◽  
R. A. Fenton ◽  
B. S. Cutler ◽  
J. G. Dobson
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Vascular Tone ◽  
Vascular Endothelial Cells ◽  
Competitive Inhibitor ◽  
No Production ◽  
Dependent Manner ◽  
Bathing Medium ◽  
Adenosine Receptor Antagonist ◽  
Potent Vasodilator

Adenosine per se is a potent vasodilator of vascular smooth muscle. Endothelial cells modulate vascular tone via the release of nitric oxide (NO), which also elicits vasodilation. This study was undertaken to determine whether adenosine could directly stimulate endothelial cells to enhance NO production, which could subsequently reduce vascular tone. NO production was evaluated in porcine carotid artery endothelial cells (PCAEC) and human saphenous vein endothelial cells (HSVEC) seeded on multiwell plates, grown to confluence, and treated with adenosine for 1 h. The bathing medium was collected, and the NO production was determined as reflected by the formation of NO2- and NO3-. NO production by PCAEC was significantly increased by adenosine in a dose-dependent manner, whereas there was only an insignificant tendency for an increase by HSVEC. The addition of the NO synthase competitive inhibitor, NG-monomethyl-L-arginine (NMMA), or the adenosine receptor antagonist, theophylline, prevented the increase in NO production by adenosine. The results suggest that adenosine stimulates, by a receptor-mediated mechanism, the production of NO by arterial, but not by venous, endothelial cells.

scholarly journals Effects of hypercapnia and hypocapnia on [Ca2+]i mobilization in human pulmonary artery endothelial cells

2001 ◽  
Vol 90 (6) ◽  
pp. 2094-2100 ◽  
Author(s):  
Kazumi Nishio ◽  
Yukio Suzuki ◽  
Kei Takeshita ◽  
Takuya Aoki ◽  
Hiroyasu Kudo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Artery ◽  
Vascular Tone ◽  
Extracellular Ph ◽  
Hypercapnic Acidosis ◽  
Extracellular Medium ◽  
Vasoactive Substances ◽  
Intracellular Ca ◽  
Human Pulmonary Artery ◽  
Hypocapnic Alkalosis

The hydrogen ion is an important factor in the alteration of vascular tone in pulmonary circulation. Endothelial cells modulate vascular tone by producing vasoactive substances such as prostacyclin (PGI2) through a process depending on intracellular Ca2+ concentration ([Ca2+]i). We studied the influence of CO2-related pH changes on [Ca2+]iand PGI2 production in human pulmonary artery endothelial cells (HPAECs). Hypercapnic acidosis appreciably increased [Ca2+]i from 112 ± 24 to 157 ± 38 nmol/l. Intracellular acidification at a normal extracellular pH increased [Ca2+]i comparable to that observed during hypercapnic acidosis. The hypercapnia-induced increase in [Ca2+]i was unchanged by the removal of Ca2+ from the extracellular medium or by the depletion of thapsigargin-sensitive intracellular Ca2+ stores. Hypercapnic acidosis may thus release Ca2+ from pH-sensitive but thapsigargin-insensitive intracellular Ca2+ stores. Hypocapnic alkalosis caused a fivefold increase in [Ca2+]i compared with hypercapnic acidosis. Intracellular alkalinization at a normal extracellular pH did not affect [Ca2+]i. The hypocapnia-evoked increase in [Ca2+]i was decreased from 242 ± 56 to 50 ± 32 nmol/l by the removal of extracellular Ca2+. The main mechanism affecting the hypocapnia-dependent [Ca2+]i increase was thought to be the augmented influx of extracellular Ca2+ mediated by extracellular alkalosis. Hypercapnic acidosis caused little change in PGI2 production, but hypocapnic alkalosis increased it markedly. In conclusion, both hypercapnic acidosis and hypocapnic alkalosis increase [Ca2+]i in HPAECs, but the mechanisms and pathophysiological significance of these increases may differ qualitatively.

A mathematical model of plasma membrane electrophysiology and calcium dynamics in vascular endothelial cells

2007 ◽  
Vol 293 (1) ◽  
pp. C277-C293 ◽  
Author(s):  
Haroldo S. Silva ◽  
Adam Kapela ◽  
Nikolaos M. Tsoukias
Keyword(s):  
Mathematical Model ◽  
Endothelial Cells ◽  
Plasma Membrane ◽  
Vascular Tone ◽  
Vascular Endothelial Cells ◽  
Anion Channel ◽  
Ionic Species ◽  
Vascular Endothelial ◽  
Health And Disease ◽  
Vascular Autoregulation

Vascular endothelial cells (ECs) modulate smooth muscle cell (SMC) contractility, assisting in vascular tone regulation. Cytosolic Ca2+ concentration ([Ca2+]i) and membrane potential ( Vm) play important roles in this process by controlling EC-dependent vasoactive signals and intercellular communication. The present mathematical model integrates plasmalemma electrophysiology and Ca2+ dynamics to investigate EC responses to different stimuli and the controversial relationship between [Ca2+]i and Vm. The model contains descriptions for the intracellular balance of major ionic species and the release of Ca2+ from intracellular stores. It also expands previous formulations by including more detailed transmembrane current descriptions. The model reproduces Vm responses to volume-regulated anion channel (VRAC) blockers and extracellular K+ concentration ([K+]o) challenges, predicting 1) that Vm changes upon VRAC blockade are [K+]o dependent and 2) a biphasic response of Vm to increasing [K+]o. Simulations of agonist-induced Ca2+ mobilization replicate experiments under control and Vm hyperpolarization blockade conditions. They show that peak [Ca2+]i is governed by store Ca2+ release while Ca2+ influx (and consequently Vm) impacts more the resting and plateau [Ca2+]i. The Vm sensitivity of rest and plateau [Ca2+]i is dictated by a [Ca2+]i “buffering” system capable of masking the Vm-dependent transmembrane Ca2+ influx. The model predicts plasma membrane Ca2+-ATPase and Ca2+ permeability as main players in this process. The heterogeneous Vm impact on [Ca2+]i may elucidate conflicting reports on how Vm influences EC Ca2+. The present study forms the basis for the development of multicellular EC-SMC models that can assist in understanding vascular autoregulation in health and disease.

scholarly journals Endothelial cells and the IGF system

2014 ◽  
Vol 54 (1) ◽  
pp. R1-R13 ◽  
Author(s):  
Leon A Bach
Keyword(s):  
Endothelial Cells ◽  
Vascular Tone ◽  
Inflammatory Responses ◽  
Therapeutic Potential ◽  
Tube Formation ◽  
Igf Binding Proteins ◽  
Igf System ◽  
Igf Binding ◽  
And Function ◽  
Cell Phenotypes

Endothelial cells line blood vessels and modulate vascular tone, thrombosis, inflammatory responses and new vessel formation. They are implicated in many disease processes including atherosclerosis and cancer. IGFs play a significant role in the physiology of endothelial cells by promoting migration, tube formation and production of the vasodilator nitric oxide. These actions are mediated by the IGF1 and IGF2/mannose 6-phosphate receptors and are modulated by a family of high-affinity IGF binding proteins. IGFs also increase the number and function of endothelial progenitor cells, which may contribute to protection from atherosclerosis. IGFs promote angiogenesis, and dysregulation of the IGF system may contribute to this process in cancer and eye diseases including retinopathy of prematurity and diabetic retinopathy. In some situations, IGF deficiency appears to contribute to endothelial dysfunction, whereas IGF may be deleterious in others. These differences may be due to tissue-specific endothelial cell phenotypes or IGFs having distinct roles in different phases of vascular disease. Further studies are therefore required to delineate the therapeutic potential of IGF system modulation in pathogenic processes.

scholarly journals Angiogenesis and angiocrines regulating heart growth

2020 ◽  
Vol 2 (1) ◽  
pp. R93-R104 ◽  
Author(s):  
Karthik Amudhala Hemanthakumar ◽  
Riikka Kivelä
Keyword(s):  
Endothelial Cells ◽  
Vascular Tone ◽  
Metabolic Diseases ◽  
Cardiac Development ◽  
Lymphatic Vessels ◽  
The Body ◽  
Transport Function ◽  
Secreted Factors ◽  
Target Organs ◽  
Treat Heart Failure

Endothelial cells (ECs) line the inner surface of all blood and lymphatic vessels throughout the body, making endothelium one of the largest tissues. In addition to its transport function, endothelium is now appreciated as a dynamic organ actively participating in angiogenesis, permeability and vascular tone regulation, as well as in the development and regeneration of tissues. The identification of endothelial-derived secreted factors, angiocrines, has revealed non-angiogenic mechanisms of endothelial cells in both physiological and pathological tissue remodeling. In the heart, ECs play a variety of important roles during cardiac development as well as in growth, homeostasis and regeneration of the adult heart. To date, several angiocrines affecting cardiomyocyte growth in response to physiological or pathological stimuli have been identified. In this review, we discuss the effects of angiogenesis and EC-mediated signaling in the regulation of cardiac hypertrophy. Identification of the molecular and metabolic signals from ECs during physiological and pathological cardiac growth could provide novel therapeutic targets to treat heart failure, as endothelium is emerging as one of the potential target organs in cardiovascular and metabolic diseases.

scholarly journals Role of P2 receptors in vascular tone regulation

2016 ◽  
Vol 97 (3) ◽  
pp. 414-421
Author(s):  
B A Ziganshin ◽  
A A Spasov ◽  
A P Ziganshina ◽  
R K Dzhordzhikiya ◽  
A U Ziganshin
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Sympathetic Nerve ◽  
Vascular Tone ◽  
Muscle Cells ◽  
P2y Receptors ◽  
P2 Receptors ◽  
P2x Receptor ◽  
Nerve Terminals

P2 receptors, the main endogenous agonist of which is adenosine triphosphate (ATP), are widely distributed in mammalian tissues and organs, including the cardiovascular system. In human blood vessels, various types of the P2Y (metabotropic, G-protein coupled receptors) and P2X (ligand-gated ion channels) family of receptors are present. Several subtypes of P2X and P2Y receptors have been found on the surface of endothelial cells as well as smooth muscle cells of the vessels. Activation of various subtypes of P2 receptors located in different cells of the blood vessel can have multidirectional action on the tone of the vessel’s wall, thereby causing both vasoconstriction and vasodilatation. To date, two main physiologic mechanisms have been identified, via which Р2 receptors participate in controlling the vascular tone: (1) neuronal - ATP is released as a co-transmitter from perivascular sympathetic nerve terminals and activates P2 receptors located on vascular smooth muscle cells; (2) endothelial - ATP is released into the vessel’s lumen by endothelial cells and blood cells and activates P2 receptors located on the endothelial cells. In the first mechanism, simultaneous release of ATP and norepinephrine from sympathetic nerve terminals results in vasoconstriction caused by rapid depolarization, which is completely inhibited by P2X receptor antagonists, and slow depolarization, which is inhibited by alpha-adrenergic blockers. In the second mechanism, during shear stress and hypoxic conditions, ATP activates P2 receptors of endothelial cells causing vasodilatation. These differing effects, mediated via P2 receptors, make it very tempting to develop novel drugs that would regulate vascular tone via these receptors.

scholarly journals Impaired Regulation of Vascular Tone by Endothelial Cells in Atherosclerosis

1997 ◽  
Vol 24 (9) ◽  
pp. 443-448
Author(s):  
Ken-ichi HIRATA ◽  
Seinosuke KAWASHIMA ◽  
Mitsuhiro YOKOYAMA
Keyword(s):  
Endothelial Cells ◽  
Vascular Tone ◽  
Regulation Of Vascular Tone

ADENINE NUCLEOTIDES AND THEREGULATION OF VASCULAR TONE

1987 ◽  
Author(s):  
J L Gordon
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Vascular Tone ◽  
Adenine Nucleotides ◽  
Muscle Cells ◽  
Vascular Endothelial ◽  
Atp Analogs ◽  
Vascular Beds

ATP, although known mainly as an intracellular energy source, is also capable of acting extracellularly as a vasoactive agent of great potency, at concentrations around lμM or less. ADP is approximately equipotent with ATP in its actions on extracellular receptors in the vasculature.ATP and ADP can arise extracellularly through release from the cytoplasm of cellsexposed to damaging stimuli or by degranulation of platelets. The concentration of the nucleotides in the cytoplasm of most cells (including vascular endothelial and smooth muscle cells) is more than ImM, and the concentration in the dense storage granules of platelets approaches 1M. Thus, there is potential for very high localised concentrations of ATP and ADP in the plasma following platelet degranulation or damageto cells of the vessel well. Release from vascular endothelial and smooth muscle cells can occur with no loss of cell viability or leakage of cytoplasmic proteins.The vasoactivity of ATP and ADP is mediated via P2 purinoceptors. Vasodilation can be induced through the release of EDRF from endothelial cells or through stimulation of PGI2 production (PGI2 is a vasodilator in many, althoughnot all, arterial beds). Purinoceptor-mediated prostacyclin production can be stimulated from perfused vascular beds (e.g. theheart andthe lung), from isolated blood vessels or from cultured endothelial cells.In some blood vessels, purinoceptor-mediated vasoconstriction can be induced by direct actionon the vascular smooth muscle cells. The receptors responsible are sub-classified as P2X (which induce vasoconstriction) and P2Y (whichinduce vasodilation). The P2Y purinoceptor that mediates EDRF production is very similar to that which is responsible for PGI2 production, although there are some intriguing differences inthe potency of ATP analogs at stimulating these two responses, even on the same cells. The intracellular mechanisms responsible have not yet been fully elucidated, but it appears that elevation of intracellular calcium is likely to play a causal role.Adenosine, which is the product of ATP and ADP metabolism by nucleotidases, can also induce vasodilation in many blood vessels, acting via P1] purinoceptors on the smooth muscle cells, but its potency is often less than that of ATP and ADP.The fate of adenine nucleotides released into the plasma is determined by ectonucleotidases on the luminal surface of the endothelial cells, not by enzymes in the blood itself (the half-life of ATP in samples of blood or plasma is many minutes, while in the microcirculation the half-life isless than one second). Endothelial ectonucleotidases have been detected in several vascular beds, and many of their characteristics are now known. These enzymes are distinct entities from the P2 purinoceptors on endothelium, as shown by the marked differences in potency of several ATP analogs as P2 receptor stimulants and as substrates for the nucleotidases.In summary, vascular endothelial and smooth muscle cells respond to extracellularATP and ADP, and can also metabolise thesenucleotides extracellularly by ectonucleotidases. In addition, ATP and ADP can be selectively released from the cells of the vessel wall and from activated platelets. Thus, the endothelial pericellular environment can be the site of complex interactions by which vascular tone is regulated through the release, actions and metabolism ofextracellular nucleotides.

scholarly journals L-Arginine/Nitric Oxide Pathway and KCa Channels in Endothelial Cells: A Mini-Review

2020 ◽  
Author(s):  
Marcelo González ◽  
José Carlos Rivas
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Function ◽  
Vascular Tone ◽  
Molecular Mechanisms ◽  
Cardiovascular Health ◽  
Kca Channels ◽  
Subsequent Activation ◽  
Regulation Of Vascular Tone

The endothelium is an organ with a key role in the maintenance of cardiovascular health through the regulation of vascular tone, vascular resistance, blood flow, and arterial pressure. These functions are related with the synthesis and release of vasoactive molecules, mainly vasodilators like nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). Both factors are released and diffused from endothelial cells to the smooth muscle cells, where there is a subsequent activation of signaling pathways that finally decrease the intracellular calcium to induce the vascular relaxation. The study of the molecular mechanisms that underlie the endothelial function still is in development, but from the evidence obtained from the endothelial cells in vitro studies are possible to partially describe the pathways to regulate the physiological endothelial function and the disturbances in pathological conditions. In this mini-review, we describe the main mechanisms for NO synthesis and the role of potassium channels related with EDHF. We include schemes and graphical summaries for better understanding of the molecular regulation of vascular tone in the human cardiovascular system.

Extracellular ATP signaling and P2X nucleotide receptors in monolayers of primary human vascular endothelial cells

2002 ◽  
Vol 282 (2) ◽  
pp. C289-C301 ◽  
Author(s):  
Lisa M. Schwiebert ◽  
William C. Rice ◽  
Brian A. Kudlow ◽  
Amanda L. Taylor ◽  
Erik M. Schwiebert
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Blood Vessels ◽  
Vascular Tone ◽  
Vascular Endothelial Cells ◽  
Purinergic Signaling ◽  
Primary Cultures ◽  
Atp Release ◽  
Vascular Endothelial ◽  
Multiple Blood

ATP and its metabolites regulate vascular tone; however, the sources of the ATP released in vascular beds are ill defined. As such, we tested the hypothesis that all limbs of an extracellular purinergic signaling system are present in vascular endothelial cells: ATP release, ATP receptors, and ATP receptor-triggered signal transduction. Primary cultures of human endothelial cells derived from multiple blood vessels were grown as monolayers and studied using a bioluminescence detection assay for ATP released into the medium. ATP is released constitutively and exclusively across the apical membrane under basal conditions. Hypotonic challenge or the calcium agonists ionomycin and thapsigargin stimulate ATP release in a reversible and regulated manner. To assess expression of P2X purinergic receptor channel subtypes (P2XRs), we performed degenerate RT-PCR, sequencing of the degenerate P2XR product, and immunoblotting with P2XR subtype-specific antibodies. Results revealed that P2X4and P2X5are expressed abundantly by endothelial cell primary cultures derived from multiple blood vessels. Together, these results suggest that components of an autocrine purinergic signaling loop exist in the endothelial cell microvasculature that may allow for “self-regulation” of endothelial cell function and modulation of vascular tone.

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