1
|
Ottolini M, Sonkusare SK. The Calcium Signaling Mechanisms in Arterial Smooth Muscle and Endothelial Cells. Compr Physiol 2021; 11:1831-1869. [PMID: 33792900 PMCID: PMC10388069 DOI: 10.1002/cphy.c200030] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The contractile state of resistance arteries and arterioles is a crucial determinant of blood pressure and blood flow. Physiological regulation of arterial contractility requires constant communication between endothelial and smooth muscle cells. Various Ca2+ signals and Ca2+ -sensitive targets ensure dynamic control of intercellular communications in the vascular wall. The functional effect of a Ca2+ signal on arterial contractility depends on the type of Ca2+ -sensitive target engaged by that signal. Recent studies using advanced imaging methods have identified the spatiotemporal signatures of individual Ca2+ signals that control arterial and arteriolar contractility. Broadly speaking, intracellular Ca2+ is increased by ion channels and transporters on the plasma membrane and endoplasmic reticular membrane. Physiological roles for many vascular Ca2+ signals have already been confirmed, while further investigation is needed for other Ca2+ signals. This article focuses on endothelial and smooth muscle Ca2+ signaling mechanisms in resistance arteries and arterioles. We discuss the Ca2+ entry pathways at the plasma membrane, Ca2+ release signals from the intracellular stores, the functional and physiological relevance of Ca2+ signals, and their regulatory mechanisms. Finally, we describe the contribution of abnormal endothelial and smooth muscle Ca2+ signals to the pathogenesis of vascular disorders. © 2021 American Physiological Society. Compr Physiol 11:1831-1869, 2021.
Collapse
Affiliation(s)
- Matteo Ottolini
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Swapnil K Sonkusare
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.,Department of Molecular Physiology & Biological Physics, University of Virginia, Charlottesville, Virginia, USA.,Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
| |
Collapse
|
2
|
Lillo MA, Gaete PS, Puebla M, Ardiles NM, Poblete I, Becerra A, Simon F, Figueroa XF. Critical contribution of Na +-Ca 2+ exchanger to the Ca 2+-mediated vasodilation activated in endothelial cells of resistance arteries. FASEB J 2018; 32:2137-2147. [PMID: 29217667 DOI: 10.1096/fj.201700365rr] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Na+-Ca2+ exchanger (NCX) contributes to control the intracellular free Ca2+ concentration ([Ca2+]i), but the functional activation of NCX reverse mode (NCXrm) in endothelial cells is controversial. We evaluated the participation of NCXrm-mediated Ca2+ uptake in the endothelium-dependent vasodilation of rat isolated mesenteric arterial beds. In phenylephrine-contracted mesenteries, the acetylcholine (ACh)-induced vasodilation was abolished by treatment with the NCXrm blockers SEA0400, KB-R7943, or SN-6. Consistent with that, the ACh-induced hyperpolarization observed in primary cultures of mesenteric endothelial cells and in smooth muscle of isolated mesenteric resistance arteries was attenuated by KB-R7943 and SEA0400, respectively. In addition, both blockers abolished the NO production activated by ACh in intact mesenteric arteries. In contrast, the inhibition of NCXrm did not affect the vasodilator responses induced by the Ca2+ ionophore, ionomycin, and the NO donor, S-nitroso- N-acetylpenicillamine. Furthermore, SEA0400, KB-R7943, and a small interference RNA directed against NCX1 blunted the increase in [Ca2+]i induced by ACh or ATP in cultured endothelial cells. The analysis by proximity ligation assay showed that the NO-synthesizing enzyme, eNOS, and NCX1 were associated in endothelial cell caveolae of intact mesenteric resistance arteries. These results indicate that the activation of NCXrm has a central role in Ca2+-mediated vasodilation initiated by ACh in endothelial cells of resistance arteries.-Lillo, M. A., Gaete, P. S., Puebla, M., Ardiles, N. M., Poblete, I., Becerra, A., Simon, F., Figueroa, X. F. Critical contribution of Na+-Ca2+ exchanger to the Ca2+-mediated vasodilation activated in endothelial cells of resistance arteries.
Collapse
Affiliation(s)
- Mauricio A Lillo
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo S Gaete
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mariela Puebla
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nicolás M Ardiles
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Inés Poblete
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alvaro Becerra
- Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas and Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy, Santiago, Chile.,Departamento de Ciencias Químicas y Biológicas, Facultad de Salud, Deporte y Recreación, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Felipe Simon
- Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas and Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
3
|
Scianna M, Bell C, Preziosi L. A review of mathematical models for the formation of vascular networks. J Theor Biol 2013; 333:174-209. [DOI: 10.1016/j.jtbi.2013.04.037] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 02/15/2013] [Accepted: 04/30/2013] [Indexed: 02/08/2023]
|
4
|
Ai S, Fan X, Fan L, Sun Q, Liu Y, Tao X, Dai K. Extraction and chemical characterization of Angelica sinensis polysaccharides and its antioxidant activity. Carbohydr Polym 2013; 94:731-6. [DOI: 10.1016/j.carbpol.2013.02.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 02/05/2013] [Accepted: 02/09/2013] [Indexed: 11/28/2022]
|
5
|
Moccia F, Berra-Romani R, Tanzi F. Update on vascular endothelial Ca 2+ signalling: A tale of ion channels, pumps and transporters. World J Biol Chem 2012; 3:127-58. [PMID: 22905291 PMCID: PMC3421132 DOI: 10.4331/wjbc.v3.i7.127] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/04/2012] [Accepted: 07/11/2012] [Indexed: 02/05/2023] Open
Abstract
A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiescence is, therefore, regarded among the early events leading to the onset and progression of potentially lethal diseases, such as hypertension, myocardial infarction, brain stroke, and tumor. Intracellular Ca2+ signals have long been know to play a central role in the complex network of signaling pathways regulating the endothelial functions. Notably, recent work has outlined how any change in the pattern of expression of endothelial channels, transporters and pumps involved in the modulation of intracellular Ca2+ levels may dramatically affect whole body homeostasis. Vascular ECs may react to both mechanical and chemical stimuli by generating a variety of intracellular Ca2+ signals, ranging from brief, localized Ca2+ pulses to prolonged Ca2+ oscillations engulfing the whole cytoplasm. The well-defined spatiotemporal profile of the subcellular Ca2+ signals elicited in ECs by specific extracellular inputs depends on the interaction between Ca2+ releasing channels, which are located both on the plasma membrane and in a number of intracellular organelles, and Ca2+ removing systems. The present article aims to summarize both the past and recent literature in the field to provide a clear-cut picture of our current knowledge on the molecular nature and the role played by the components of the Ca2+ machinery in vascular ECs under both physiological and pathological conditions.
Collapse
Affiliation(s)
- Francesco Moccia
- Francesco Moccia, Franco Tanzi, Department of Biology and Biotechnologies "Lazzaro Spallanzani", Laboratory of Physiology, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | | | | |
Collapse
|
6
|
Willer EA, Malli R, Bondarenko AI, Zahler S, Vollmar AM, Graier WF, Fürst R. The vascular barrier-protecting hawthorn extract WS® 1442 raises endothelial calcium levels by inhibition of SERCA and activation of the IP3 pathway. J Mol Cell Cardiol 2012; 53:567-77. [PMID: 22814436 DOI: 10.1016/j.yjmcc.2012.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 07/06/2012] [Indexed: 10/28/2022]
Abstract
WS® 1442 has been proven as an effective and safe therapeutical to treat mild forms of congestive heart failure. Beyond this action, we have recently shown that WS® 1442 protects against thrombin-induced vascular barrier dysfunction and the subsequent edema formation by affecting endothelial calcium signaling. The aim of the study was to analyze the influence of WS® 1442 on intracellular calcium concentrations [Ca(2+)](i) in the human endothelium and to investigate the underlying mechanisms. Using ratiometric calcium measurements and a FRET sensor, we found that WS® 1442 concentration-dependently increased basal [Ca(2+)](i) by depletion of the endoplasmic reticulum (ER) and inhibited a subsequent histamine-triggered rise of [Ca(2+)](i). Interestingly, the augmented [Ca(2+)](i) did neither trigger an activation of the contractile machinery nor led to a barrier breakdown (macromolecular permeability). It also did not impair endothelial cell viability. As assessed by patch clamp recordings, WS® 1442 did only slightly affect endothelial Na(+)/K(+)-ATPase, but increased [Ca(2+)](i) by inhibiting the sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase (SERCA) and by activating the inositol 1,4,5-trisphosphate (IP(3)) pathway. Most importantly, WS® 1442 did not induce store-operated calcium entry (SOCE), but even irreversibly prevented histamine-induced SOCE. Taken together, WS® 1442 prevented the deleterious hyperpermeability-associated rise of [Ca(2+)](i) by a preceding, non-toxic release of Ca(2+) from the ER. WS® 1442 interfered with SERCA and the IP(3) pathway without inducing SOCE. The elucidation of this intriguing mechanism helps to understand the complex pharmacology of the cardiovascular drug WS® 1442.
Collapse
Affiliation(s)
- Elisabeth A Willer
- Department of Pharmacy, Centre for Drug Research, Pharmaceutical Biology, University of Munich, Butenandtstr. 5-13, 81377 Munich, Germany
| | | | | | | | | | | | | |
Collapse
|
7
|
Scianna M. A Multiscale Hybrid Model for Pro-angiogenic Calcium Signals in a Vascular Endothelial Cell. Bull Math Biol 2011; 74:1253-91. [DOI: 10.1007/s11538-011-9695-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 09/06/2011] [Indexed: 01/07/2023]
|
8
|
A multiscale hybrid approach for vasculogenesis and related potential blocking therapies. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2011; 106:450-62. [PMID: 21300081 DOI: 10.1016/j.pbiomolbio.2011.01.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 01/25/2011] [Accepted: 01/27/2011] [Indexed: 12/16/2022]
Abstract
Solid tumors must recruit and form new blood vessels for maintenance, growth and detachments of metastases. Discovering drugs that block malignant angiogenesis is thus an important approach in cancer treatment and has given rise to multiple in vitro and in silico models. The present hybrid individual cell-based model incorporates some underlying biochemical events relating more closely the classical Cellular Potts Model (CPM) parameters to subcellular mechanisms and to the activation of specific signaling pathways. The model spans the three fundamental biological levels: at the extracellular level a continuous model describes secretion, diffusion, uptake and decay of the autocrine VEGF; at the cellular level, an extended lattice CPM, based on a system energy reduction, reproduces cell dynamics such as migration, adhesion and chemotaxis; at the subcellular level, a set of reaction-diffusion equations describes a simplified VEGF-induced calcium-dependent intracellular pathway. The results agree with the known interplay between calcium signals and VEGF dynamics and with their role in malignant vasculogenesis. Moreover, the analysis of the link between the microscopic subcellular dynamics and the macroscopic cell behaviors confirms the efficiency of some pharmacological interventions that are currently in use and, more interestingly, proposes some new therapeutic approaches, that are counter-intuitive but potentially effective.
Collapse
|
9
|
Scianna M, Munaron L. Multiscale model of tumor-derived capillary-like network formation. ACTA ACUST UNITED AC 2011. [DOI: 10.3934/nhm.2011.6.597] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
10
|
Palmerini CA, Mazzoni M, Saccardi C, Arienti G. The cytosolic calcium concentration is affected by S-nitrosocysteine in human lymphomonocytes. J Biochem Mol Toxicol 2008; 22:35-40. [PMID: 18273907 DOI: 10.1002/jbt.20211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The homeostasis of cytosolic calcium [Ca2+](c) in mammalian cells is a complex phenomenon, requiring the contribution of many cellular and extracellular systems. Nitric oxide (NO) acts on [Ca2+](c), although the mechanism of this action is unknown. We study the release and the uptake of Ca2+ in the endoplasmic reticulum and its capacitative entry in human lymphomonocytes in the presence of the NO donor S-nitrosocysteine (CysNO) at low (16 microM) and at high (160 microM) concentrations by measuring the [Ca2+](c) by the Fura 2-AM method. Thapsigargin (TG), which inhibits sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), and nifedipine (NIF), which blocks the Ca2+ release from intracellular stores, are used to clarify the effects of NO on calcium movements. In the absence of extracellular Ca2+, CysNO decreases basal [Ca2+](c), whereas TG increases it as the result of SERCA inhibition. This effect of TG diminishes in the presence of the NO donor. In the presence of extracellular Ca2+(capacitative entry conditions), CysNO does not influence Ca2+ entry but reduces the toxic effects of TG connected to the increase of [Ca2+](c) in these conditions. The effect of NIF is, up to a certain extent, similar to that of CysNO, although the mechanisms of action of the two agents do not seem related. We conclude that CysNO participates in [Ca2+](c) homeostasis by stimulating the movement of the ion from the cytosol to other compartments.
Collapse
Affiliation(s)
- Carlo A Palmerini
- Department of Internal Medicine, The Medical School, University of Perugia, Via del Giochetto, 06122 Perugia, Italy.
| | | | | | | |
Collapse
|
11
|
Age‐associated alterations of lipofuscin, membrane‐bound ATPases and intracellular calcium in cortex, striatum and hippocampus of rat brain: protective role of glutathione monoester. Int J Dev Neurosci 2007; 26:211-5. [DOI: 10.1016/j.ijdevneu.2007.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Accepted: 12/14/2007] [Indexed: 11/22/2022] Open
|
12
|
Selvam R, Ganesan K, Narayana Raju KVS, Gangadharan AC, Manohar BM, Puvanakrishnan R. Low frequency and low intensity pulsed electromagnetic field exerts its antiinflammatory effect through restoration of plasma membrane calcium ATPase activity. Life Sci 2007; 80:2403-10. [PMID: 17537462 DOI: 10.1016/j.lfs.2007.03.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 02/20/2007] [Accepted: 03/26/2007] [Indexed: 12/26/2022]
Abstract
Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting 1% of the population worldwide. Pulsed electromagnetic field (PEMF) has a number of well-documented physiological effects on cells and tissues including antiinflammatory effect. This study aims to explore the antiinflammatory effect of PEMF and its possible mechanism of action in amelioration of adjuvant induced arthritis (AIA). Arthritis was induced by a single intradermal injection of heat killed Mycobacterium tuberculosis at a concentration of 500 microg in 0.1 ml of paraffin oil into the right hind paw of rats. The arthritic animals showed a biphasic response regarding changes in the paw edema volume. During the chronic phase of the disease, arthritic animals showed an elevated level of lipid peroxides and depletion of antioxidant enzymes with significant radiological and histological changes. Besides, plasma membrane Ca(2+) ATPase (PMCA) activity was inhibited while intracellular Ca(2+) level as well as prostaglandin E(2) levels was noticed to be elevated in blood lymphocytes of arthritic rats. Exposure of arthritic rats to PEMF at 5 Hzx4 microT x 90 min, produced significant antiexudative effect resulting in the restoration of the altered parameters. The antiinflammatory effect could be partially mediated through the stabilizing action of PEMF on membranes as reflected by the restoration of PMCA and intracellular Ca(2+) levels in blood lymphocytes subsequently inhibiting PGE(2) biosynthesis. The results of this study indicated that PEMF could be developed as a potential therapy for RA in human beings.
Collapse
Affiliation(s)
- Ramasamy Selvam
- Department of Pharmacology and Toxicology, Madras Veterinary College, Vepery, Chennai, India
| | | | | | | | | | | |
Collapse
|
13
|
Jesudason EP, Masilamoni JG, Jesudoss KS, Jayakumar R. The protective role of DL-?-lipoic acid in the oxidative vulnerability triggered by A?-amyloid vaccination in mice. Mol Cell Biochem 2005; 270:29-37. [PMID: 15792351 DOI: 10.1007/s11010-005-3301-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recent reports indicate that beta-amyloid peptide (Abeta) vaccine based therapy for Alzheimer's disease (AD) may be on the horizon. There are however, concerns about the safety of this approach. Immunization with Abeta has several disadvantages, because it crosses the blood brain barrier and cause inflammation and neurotoxicity. The present work is aimed to study the protective effective of alpha-lipoic acid (LA) in the oxidative vulnerability of beta-amyloid in plasma, liver, spleen and brain, when Abeta fibrils are given intraperitoneally in inflammation induced mice. Result shows that reactive oxygen species (ROS) in the astrocytes of inflammation induced mice along with Abeta (IA) has shown 2.5-fold increase when compared with LA treated mice. The increased level of lipid peroxidase (LPO) (p < 0.05) and decreased antioxidant status (p < 0.05) were observed in the plasma, liver, spleen and brain of LA induced mice when compared with LA treated mice. Data shows that there were no significant changes observed between the control and LA treated mice. Our biochemical and histological results highlight that significant oxidative vulnerability was observed in IA treated mice, which was prevented by LA therapy. Our findings suggest that the antioxidant effect of LA when induced with Abeta may serve as a potent therapeutic tool for inflammatory AD models.
Collapse
Affiliation(s)
- E Philip Jesudason
- Bio-Organic and Neurochemistry Laboratory, Central Leather Research Institute, Adyar, Chennai, India
| | | | | | | |
Collapse
|
14
|
Dong XH, Komiyama Y, Nishimura N, Masuda M, Takahashi H. Nanomolar level of ouabain increases intracellular calcium to produce nitric oxide in rat aortic endothelial cells. Clin Exp Pharmacol Physiol 2005; 31:276-83. [PMID: 15191398 DOI: 10.1111/j.1440-1681.2004.03995.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Changes in [Ca(2+)](i) across the cell membrane and/or the sarcoplasmic reticulum regulate endothelial nitric oxide (NO) synthase activity. In the present study, we investigated the effect of ouabain, a specific inhibitor of Na(+)/K(+)-ATPase, on NO release and [Ca(2+)](i) movements in cultured rat aortic endothelial cells (RAEC) by monitoring NO production continuously using an NO-specific real-time sensor and by measuring the change in [Ca(2+)](i) using a fluorescence microscopic imaging technique with high-speed wavelength switching. The t((1/2)) (half-time of the decline of [Ca(2+)](i) to basal levels after stimulation with 10 micro mol/L bradykinin) was used as an index of [Ca(2+)](i) extrusion. A very low concentration of ouabain (10 nmol/L) did not increase the peak of NO production, but decreased the decay of NO release and, accordingly, increased integral NO production by the maximal dose-response concentration induced by bradykinin. The same dose of ouabain affected [Ca(2+)](i) movements across the cell membrane and/or sarcoplasmic reticulum induced by bradykinin with a time-course similar to that of NO release. Moreover, the t((1/2)) was significantly increased. Pretreatment of RAEC with Na(+)-free solution, an inhibitor of the Na(+)/Ca(2+) exchanger, and nickel chloride hexahydrate prevented the effects induced by bradykinin and ouabain. These observations using real-time recording indicate that a small amount of ouabain contributes to the bradykinin-stimulated increase of NO production through inhibition of plasma membrane Na(+)/K(+)-ATPase activity and an increase in intracellular Na(+) concentrations. The membrane was then depolarized, leading to a decline in the bradykinin-stimulated increase in [Ca(2+)](i) by forward mode Na(+)/Ca(2+) exchange to prolong the Ca(2+) signal time. From these results, we suggest that nanomolar levels of ouabain modulate [Ca(2+)](i) movements and NO production in RAEC.
Collapse
Affiliation(s)
- Xian Hui Dong
- Department of Clinical Sciences and Laboratory Medicine, Kansai Medical University, Moriguchi, Osaka, Japan
| | | | | | | | | |
Collapse
|
15
|
Bondarenko A. Sodium-calcium exchanger contributes to membrane hyperpolarization of intact endothelial cells from rat aorta during acetylcholine stimulation. Br J Pharmacol 2004; 143:9-18. [PMID: 15289290 PMCID: PMC1575260 DOI: 10.1038/sj.bjp.0705866] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The role of sodium-calcium exchanger in acetylcholine (Ach)-induced hyperpolarization of intact endothelial cells was studied in excised rat aorta. The membrane potential was recorded using perforated patch-clamp technique. 2. The mean resting potential of endothelial cells was -44.1+/-1.4 mV. A selective inhibitor of sodium-calcium exchanger benzamil (100 microm) had no significant effect on resting membrane potential, but reversibly decreased the amplitude of sustained Ach-induced endothelial hyperpolarization from 20.9+/-1.4 to 5.7+/-1.1 mV when applied during the plateau phase. 3. The blocker of reversed mode of the exchanger KB-R7943 (2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea methanesulfonate, 20 microm) reversibly decreased the amplitude of sustained Ach-induced hyperpolarization from 20.5+/-2.9 to 7.5+/-1.8 mV. 4. Introduction of tetraethylammonium (10 mm) in the continuous presence of Ach decreased the sustained phase of hyperpolarization from 17.9+/-1.5 by 12.9+/-0.9 mV. Subsequent addition of 20 microm KB-R7943 further depolarized endothelial cells by 4.8+/-1.1 mV. 5. Substituting external sodium with N-methyl d-glucamine during the plateau phase of Ach-evoked hyperpolarization reversibly decreased the hyperpolarization from -61.8+/-2.7 to -54.2+/-1.9 mV. In the majority of preparations, the initial response to removal of external sodium was a transient further rise in the membrane potential of several mV. Sodium ionophore monensin hyperpolarized endothelium by 10.3+/-0.7 mV. 6. The inhibitory effect of benzamil on Ach-induced endothelial sustained hyperpolarization was observed in endothelium mechanically isolated from smooth muscle. 7. These results suggest that the sodium-calcium exchanger of intact endothelial cells is able to operate in reverse following stimulation by Ach, contributing to sustained hyperpolarization. Myoendothelial electrical communications do not mediate the effect of blockers of sodium-calcium exchanger.
Collapse
MESH Headings
- Acetylcholine/pharmacology
- Adrenergic alpha-Agonists/pharmacology
- Amiloride/analogs & derivatives
- Amiloride/pharmacology
- Animals
- Aorta, Thoracic/cytology
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiology
- Calcium/metabolism
- Cell Membrane/metabolism
- Cell Membrane/physiology
- Diuretics/pharmacology
- Endothelial Cells/drug effects
- Endothelial Cells/metabolism
- Endothelial Cells/physiology
- Female
- Gap Junctions/drug effects
- In Vitro Techniques
- Ionophores/pharmacology
- Male
- Membrane Potentials/drug effects
- Monensin/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Phenylephrine/pharmacology
- Rats
- Sodium/physiology
- Sodium-Calcium Exchanger/physiology
- Stimulation, Chemical
- Thiourea/analogs & derivatives
- Thiourea/pharmacology
Collapse
Affiliation(s)
- Alexander Bondarenko
- Department of Blood Circulation, AA Bogomoletz Institute of Physiology, NAS of Ukraine, 4, Bogomoletz Str., Kiev 01024, Ukraine.
| |
Collapse
|
16
|
Schuster A, Lamboley M, Grange C, Oishi H, Bény JL, Stergiopulos N, Meister JJ. Calcium Dynamics and Vasomotion in Rat Mesenteric Arteries. J Cardiovasc Pharmacol 2004; 43:539-48. [PMID: 15085065 DOI: 10.1097/00005344-200404000-00009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Smooth muscle cell calcium dynamics and diameter were measured in intact pressurized rat mesenteric artery segments during vasoconstriction and vasomotion. Arteries showed a certain norepinephrine (NE) threshold (0.3-0.4 microM) for the onset of vasomotion, during a cumulative NE concentration-response curve. This was due to a necessary [Ca2+]i threshold (increase over basal level of 22.2 +/- 2.6%) to elicit oscillations. The calcium oscillations obtained were synchronous over the entire vessel length and phase-shifted (in advance by 1.7 +/- 0.3 seconds) with respect to the diameter oscillations. A similar result was obtained using a KCl depolarization to contract the arteries, even though the [Ca2+]i threshold was much smaller in this case (increase over basal level of 9.9 +/- 4.3%), as compared with the NE-elicited vasomotion. Blockade of the Na+/K+-ATPase with 1 microM ouabain, or of the Na+/Ca2+ exchanger (NCX) with 1 microM KB-R 7943, did not abolish the calcium oscillations, thus showing that these two pumps are only modulatory elements, while on the other hand, voltage-gated calcium channels have been found to be important in the vasomotion mechanism.
Collapse
Affiliation(s)
- Alexander Schuster
- Cellular Biophysics and Biomechanics Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
17
|
Wang X, Reznick S, Li P, Liang W, van Breemen C. Ca(2+) removal mechanisms in freshly isolated rabbit aortic endothelial cells. Cell Calcium 2002; 31:265-77. [PMID: 12098216 DOI: 10.1016/s0143-4160(02)00075-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Calcium removal from the cytoplasm was investigated in freshly isolated aortic endothelial cells by monitoring changes in intracellular calcium ([Ca(2+)](i)) using ratiometric fura-2 fluorimetry. Blockade of the Na(+)/Ca(2+) exchanger (NCX) by replacement of external sodium with equi-molar N-methyl-D-glutamine (0Na PSS) decreased the removal rate by 52%. Blockade of the sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) by cyclopiazonic acid (CPA) decreased the removal rate by 50%. Simultaneous application of CPA and 0Na PSS did not reduce the removal rate any further (53%). The lack of additivity of these two procedures, suggests that SERCA and the NCX function in series to lower [Ca(2+)](i). In addition, in the absence of extracellular Ca(2+), removal of external Na(+) markedly reduced the rate of loss of Ca(2+) from the ER further supporting the hypothesis that NCX is functionally linked to ER calcium release channels, and thus, plays an important role in ER calcium unloading. To investigate the mechanism for the coupling of NCX and SERCA, the same protocols as described above were repeated after treating the cells with cytochalasin D, which disrupts the cytoskeleton. This treatment uncoupled the NCX from SERCA, as evidenced by the resulting additive inhibitory effects of application of CPA and removal of extracellular Na(+) on the rate of Ca(2+) removal from the cytoplasm. These data suggest that in endothelial cells NCX and SERCA function in series to remove about half of the free Ca(2+) from the cytosol, while PMCA contributes to the other half of the Ca(2+) removal process.
Collapse
Affiliation(s)
- X Wang
- Department of Pharmacology and Therapeutics, Vancouver Vascular Biology Research Center, University of British Columbia, Vancouver, Canada V6T 1Z3.
| | | | | | | | | |
Collapse
|
18
|
Chauhan VPS, Tsiouris JA, Chauhan A, Sheikh AM, Brown WT, Vaughan M. Increased oxidative stress and decreased activities of Ca(2+)/Mg(2+)-ATPase and Na(+)/K(+)-ATPase in the red blood cells of the hibernating black bear. Life Sci 2002; 71:153-61. [PMID: 12031685 DOI: 10.1016/s0024-3205(02)01619-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
During hibernation, animals undergo metabolic changes that result in reduced utilization of glucose and oxygen. Fat is known to be the preferential source of energy for hibernating animals. Malonyldialdehyde (MDA) is an end product of fatty acid oxidation, and is generally used as an index of lipid peroxidation. We report here that peroxidation of lipids is increased in the plasma and in the membranes of red blood cells in black bears during hibernation. The plasma MDA content was about four fold higher during hibernation as compared to that during the active, non-hibernating state (P < 0.0001). Similarly, MDA content of erythrocyte membranes was significantly increased during hibernation (P < 0.025). The activity of Ca(2+)/Mg(2+)-ATPase in the erythrocyte membrane was significantly decreased in the hibernating state as compared to the active state. Na(+)/K(+)-ATPase activity was also decreased, though not significant, during hibernation. These results suggest that during hibernation, the bears are under increased oxidative stress, and have reduced activities of membrane-bound enzymes such as Ca(2+)/Mg(2+)-ATPase and Na(+)/K(+)-ATPase. These changes can be considered part of the adaptive for survival process of metabolic depression.
Collapse
Affiliation(s)
- Ved P S Chauhan
- NYS Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA.
| | | | | | | | | | | |
Collapse
|
19
|
Moccia F, Berra-Romani R, Baruffi S, Spaggiari S, Signorelli S, Castelli L, Magistretti J, Taglietti V, Tanzi F. Ca2+ uptake by the endoplasmic reticulum Ca2+-ATPase in rat microvascular endothelial cells. Biochem J 2002; 364:235-44. [PMID: 11988097 PMCID: PMC1222566 DOI: 10.1042/bj3640235] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In non-excitable cells, many agonists increase the intracellular Ca(2+) concentration ([Ca(2+)](i)) by inducing an inositol 1,4,5-trisphosphate (IP(3))-mediated Ca(2+) release from the intracellular stores. Ca(2+) influx from the extracellular medium may then sustain the Ca(2+) signal. [Ca(2+)](i) recovers its resting level as a consequence of Ca(2+)-removing mechanisms, i.e. plasma-membrane Ca(2+)-ATPase (PMCA) pump, Na(+)/Ca(2+) exchanger (NCX) and sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA) pump. In a study performed in pancreatic acinar cells, evidence has been provided suggesting that, during the decay phase of the agonist-evoked Ca(2+) transients, the Ca(2+) concentration within the intracellular stores remains essentially constant [Mogami, Tepikin and Petersen (1998) EMBO J. 17, 435-442]. It was therefore hypothesized that, in such a situation, intracellular Ca(2+) is not only picked up by the SERCA pump, but is also newly released through IP(3)-sensitive Ca(2+) channels, with the balance between these two processes being approximately null. The main aim of the present work was to test this hypothesis by a different experimental approach. Using cardiac microvascular endothelial cells, we found that inhibition of the SERCA pump has no effect on the time course of agonist-evoked Ca(2+) transients. This result was not due to a low capacity of the SERCA pump since, after agonist removal, this pump proved to be very powerful in clearing the excess of intracellular Ca(2+). We showed further that: (i) in order to avoid a rapid removal of Ca(2+) by the SERCA pump, continuous IP(3) production appears to be required throughout all of the decay phase of the Ca(2+) transient; and (ii) Ca(2+) picked up by the SERCA pump can be fully and immediately released by agonist application. All these results support the model of Mogami, Tepikin and Petersen [(1998) EMBO J. 17, 435-442]. Since the SERCA pump did not appear to be involved in shaping the decay phase of the agonist-evoked Ca(2+) transient, we inhibited the PMCA pump with carboxyeosin, and NCX with benzamil and by removing extracellular Na(+). The results indicate that, during the decay phase of the agonist-evoked Ca(2+) transient, the intracellular Ca(2+) is removed by both the PMCA pump and NCX. Finally, we provide evidence indicating that mitochondria have no role in clearing intracellular Ca(2+) during agonist-evoked Ca(2+) transients.
Collapse
Affiliation(s)
- Francesco Moccia
- Department of Physiological and Pharmacological Sciences, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Dedkova EN, Blatter LA. Nitric oxide inhibits capacitative Ca2+ entry and enhances endoplasmic reticulum Ca2+ uptake in bovine vascular endothelial cells. J Physiol 2002; 539:77-91. [PMID: 11850503 PMCID: PMC2290138 DOI: 10.1113/jphysiol.2001.013258] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2001] [Accepted: 11/08/2001] [Indexed: 11/08/2022] Open
Abstract
In vascular endothelial cells, elevation of cytosolic free calcium concentration ([Ca2+]i) causes activation of nitric oxide synthase (NOS) and release of nitric oxide (NO). The goal of the study was to characterize the interplay between [Ca2+]i and NO production in this cell type. Simultaneous measurements of [Ca2+]i and intracellular NO concentration ([NO]i) in cultured bovine vascular endothelial cells (CPAE cell line) with the fluorescent indicators fura-2 and DAF-2, respectively, revealed that Ca2+ influx following agonist-induced intracellular Ca2+ store depletion (capacitative Ca2+ entry, CCE) represents the preferential Ca2+ source for the activation of the Ca2+-calmodulin-dependent endothelial NOS (eNOS). Exposure to the NO donor sodium nitroprusside (SNP) showed that high NO levels suppressed CCE and had an inhibitory effect on Ca2+ extrusion by the plasmalemmal Ca2+-ATPase. This inhibitory effect on CCE was mimicked by the membrane-permeant cGMP analogue 8-bromo-cGMP, but was reversed by the NO scavenger haemoglobin and prevented by the inhibitor of the NO-sensitive guanylate cyclase ODQ. Brief exposure to SNP reduced the peak of ATP-induced Ca2+ release from the endoplasmic reticulum (ER) and accelerated Ca2+ reuptake into the ER. Prolonged incubation with SNP resulted in enhanced Ca2+ loading of the ER, as revealed by direct measurements of store content with the ER-entrapped low-affinity Ca2+ indicator mag-fura-2. The results suggest that in vascular endothelial cells, NO synthesis is under autoregulatory control that involves NO-dependent [Ca2+]i regulation. Via cGMP-dependent inhibition of CCE and acceleration of Ca2+ sequestration into the ER, NO can lower [Ca2+]i and therefore exert an autoregulatory negative feedback on its own Ca2+-dependent synthesis.
Collapse
Affiliation(s)
- Elena N Dedkova
- Department of Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL 60153, USA
| | | |
Collapse
|
21
|
Jain SK, Lim G. Lipoic acid decreases lipid peroxidation and protein glycosylation and increases (Na(+) + K(+))- and Ca(++)-ATPase activities in high glucose-treated human erythrocytes. Free Radic Biol Med 2000; 29:1122-8. [PMID: 11121719 DOI: 10.1016/s0891-5849(00)00410-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lipoic acid supplementation has been found to be beneficial in preventing neurovascular abnormalities in diabetic neuropathy. Insufficient (Na(+) + K(+))-ATPase activity has been suggested as a contributing factor in the development of diabetic neuropathy. This study was undertaken to test the hypothesis that lipoic acid reduces lipid peroxidation and glycosylation and can increase the (Na(+) + K(+))- and Ca(++)-ATPase activities in high glucose-exposed red blood cells (RBC). Washed normal human RBC were treated with normal (6 mM) and high glucose concentrations (45 mM) with 0-0.2 mM lipoic acid (mixture of S and R sterioisomers) in a shaking water bath at 37 degrees C for 24 h. There was a significant stimulation of glucose consumption by RBC in the presence of lipoic acid both in normal and high glucose-treated RBC. Lipoic acid significantly lowered the level of glycated hemoglobin (GHb) and lipid peroxidation in RBC exposed to high glucose concentrations. High glucose treatment significantly lowered the activities of (Na(+) + K(+))- and Ca(++)-ATPases of RBC membranes. Lipoic acid addition significantly blocked the reduction in activities of (Na(+) + K(+))- and Ca(++)-ATPases in high glucose- treated RBC. There were no differences in lipid peroxidation, GHb and (Na(+) + K(+))- and Ca(++)-ATPase activity levels in normal glucose-treated RBC with and without lipoic acid. Thus, lipoic acid can lower lipid peroxidation and protein glycosylation, and increase (Na(+) + K(+))- and Ca(++)-ATPase activities in high-glucose exposed RBC, which provides a potential mechanism by which lipoic acid may delay or inhibit the development of neuropathy in diabetes.
Collapse
Affiliation(s)
- S K Jain
- Department of Pediatrics, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
| | | |
Collapse
|
22
|
Chen J, Wang Y, Nakajima T, Iwasawa K, Hikiji H, Sunamoto M, Choi DK, Yoshida Y, Sakaki Y, Toyo-Oka T. Autocrine action and its underlying mechanism of nitric oxide on intracellular Ca2+ homeostasis in vascular endothelial cells. J Biol Chem 2000; 275:28739-49. [PMID: 10852903 DOI: 10.1074/jbc.m000910200] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The rise in cytosolic Ca(2+) concentration (Ca(2+)(i)) in vascular endothelial cells (ECs) activates the production and release of nitric oxide (NO). NO modifies Ca(2+)(i) homeostasis in many types of nonendothelial cells. However, its effect on endothelial Ca(2+)(i) homeostasis at basal and excited states remains unclear. In the present study, to elucidate the effect of NO on basal Ca(2+)(i), inositol 1,4,5-trisphosphate-induced Ca(2+)(i) release (IICR) was blocked by expressing an antisense against type-1 inositol 1,4,5-trisphosphate receptors or by microinjecting heparin to individual ECs, and the effects of NO that was released by and diffused from adjacent IICR-intact ECs were recorded. After ATP or bradykinin stimulation, IICR-inhibited ECs showed a marked reduction of basal Ca(2+)(i), which was abolished by N(G)-monomethyl-l-arginine monoacetate pretreatment. The reduction disappeared in sparsely seeded ECs. Exogenous NO gas mimicked the effect of ATP or bradykinin to reduce basal Ca(2+)(i). Blocking plasma membrane Ca(2+)-ATPase (PMCA), but not Na(+)-Ca(2+) exchange or sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase, suppressed the reduction, indicating that the reduction resulted from a NO-dependent potentiation of PMCA. To elucidate the effect of NO on elevated Ca(2+)(i), ATP-, bradykinin-, or thapsigargin-evoked Ca(2+)(i) response in the presence and absence of NO production was compared in adjacent IICR-intact ECs. NO was found to potentiate PMCA, which, in turn, greatly attenuated agonist-evoked Ca(2+)(i) elevation. NO also potentiated Ca(2+) influx, which markedly increased the sustained phase of Ca(2+)(i) elevation and possibly NO production. NO did not affect other Ca(2+)(i)-elevating and Ca(2+)(i)-sequestrating components. Thus, NO-dependent potentiation of PMCA is crucial for Ca(2+)(i) homeostasis over a wide Ca(2+)(i) range.
Collapse
Affiliation(s)
- J Chen
- Second Department of Internal Medicine, the Department of Oral and Maxillofacial Surgery, and the Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo 113-0033, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
McConnell EJ, White GW, Brokaw JJ, Raess BU. Pharmacological and immunohistochemical characterization of calmodulin-stimulated (Ca(2+)+Mg(2+))-ATPase in cultured porcine aortic endothelial cells. Circ Res 2000; 86:191-7. [PMID: 10666415 DOI: 10.1161/01.res.86.2.191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Plasma membrane (Ca(2+)+Mg(2+))-ATPase and Ca(2+) transport activities, best characterized in human erythrocytes, are stimulated by calmodulin and thought to play a crucial role in the termination of cellular Ca(2+) signaling in all cells. In plasma membranes isolated from cultured porcine aortic endothelial cells, the (Ca(2+)+Mg(2+))-ATPase was not readily measured. This is in part because of an overabundance of nonspecific Ca(2+)- and/or Mg(2+)-activated ecto-5'-nucleotide phosphohydrolases. Moreover, addition of exogenous calmodulin (10(-9) to 10(-6) mol/L) produced no measurable stimulation of ATPase activities, suggesting a permanently activated state or, alternatively, a complete lack thereof. To establish and verify the presence of a calmodulin-regulated (Ca(2+)+Mg(2+))-ATPase activity in these endothelial cells, immunohistochemical localization using a monoclonal mouse anti-(Ca(2+)+Mg(2+))-ATPase antibody (clone 5F10) was applied to intact pig aorta endothelium, cultured endothelial monolayers, and isolated endothelial plasma membrane fractions. This approach clearly demonstrated Ca(2+) pump immunoreactivity in each of these preparations. To confirm functional calmodulin stimulation of the (Ca(2+)+Mg(2+))-ATPase, 10(-5) mol/L calmidazolium (R24571) was added to the isolated plasma membrane preparation, which lowered the (Ca(2+)+Mg(2+))-ATPase activity from 143.0 to 78.15 nmol P(i)/mg protein x min(-1). This calmidazolium-reduced activity could then be stimulated 113.1+/-0.8% in a concentration-dependent manner by the addition of exogenous calmodulin (10(-7) to 2 x 10(-6) mol/L) with an EC(50) of 3.45+/-0.04 x 10(-7) mol/L (n=4). This represents a competitive lowering of the apparent calmodulin affinity by approximately 100 compared with other unopposed calmodulin-stimulated processes. Together, these findings support evidence for the presence of a calmodulin-stimulated plasma membrane (Ca(2+)+Mg(2+))-ATPase activity in cultured porcine aortic endothelial cells.
Collapse
Affiliation(s)
- E J McConnell
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Evansville, IN 47712, USA
| | | | | | | |
Collapse
|
24
|
Nakao M, Furukawa K, Satoh E, Ono K, Iijima T. Inhibition by antisense oligonucleotides of plasma membrane Ca(2+) ATPase in vascular endothelial cells. Eur J Pharmacol 2000; 387:273-7. [PMID: 10650172 DOI: 10.1016/s0014-2999(99)00823-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Antisense oligodeoxynucleotides were used to knock down plasma membrane Ca(2+) ATPase, and the role of plasma membrane Ca(2+) ATPase was investigated in human aortic endothelial (HAE) cells. The peak of thapsigargin-evoked intracellular Ca(2+) concentration ([Ca(2+)](i)) was higher in antisense-treated than in untreated cells, but the declining time course was unaffected by the antisense treatment. The declining time was prolonged in both antisense-treated and untreated cells by reducing external Na(+), but the prolongation was more marked in the antisense-treated cells. These results provide the evidence of a functional role of plasma membrane Ca(2+) ATPase, although other mechanisms including Na(+)/Ca(2+) exchange may play the primary role in regulating [Ca(2+)](i).
Collapse
Affiliation(s)
- M Nakao
- Department of Pharmacology, Akita University School of Medicine, 1-1-1 Hondoh, Akita, Japan
| | | | | | | | | |
Collapse
|