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Pasupathy S, Tavella R, Zeitz C, Edwards S, Worthley M, Arstall M, Beltrame JF. Anti-Anginal Efficacy of Zibotentan in the Coronary Slow-Flow Phenomenon. J Clin Med 2024; 13:1337. [PMID: 38592159 PMCID: PMC10931575 DOI: 10.3390/jcm13051337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/07/2024] [Accepted: 02/20/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND Patients with coronary microvascular disorders often experience recurrent angina for which there are limited evidence-based therapies. These patients have been found to exhibit increased plasma levels of endothelin; thus, selective endothelin-A (Et-A) receptor blockers such as zibotentan may be an effective anti-anginal therapy in these patients. The study evaluated the impact of a 10 mg daily dose of zibotentan on spontaneous angina episodes in patients with the coronary slow-flow phenomenon who had refractory angina (i.e., experiencing angina at least three times/week despite current anti-anginal therapy). METHODS Using a randomized, double-blind, placebo-controlled, crossover trial design with 4-week treatment periods, 18 patients (63.2 ± 9.9 years, 33% females) were recruited. The primary endpoint was angina frequency as measured by an angina diary, with secondary endpoints including nitrate consumption, angina duration/severity and the Seattle Angina Questionnaire (SAQ) domains. RESULTS During the 4 weeks of therapy, angina frequency significantly improved with zibotentan therapy (placebo 41.4 (58.5) vs. zibotentan 29.2 (31.6), p < 0.05), and sublingual nitrate consumption significantly reduced (placebo 11.8 (15.2) vs. zibotentan 8.8 (12.9), p < 0.05. CONCLUSIONS Zibotentan improved the frequency of spontaneous angina episodes and reduced sublingual nitrate consumption in patients unresponsive to standard anti-anginal therapy.
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Affiliation(s)
- Sivabaskari Pasupathy
- School of Medicine, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5000, Australia; (S.P.); (R.T.); (C.Z.); (S.E.); (M.W.); (M.A.)
- Central Adelaide Local Health Network, Adelaide, SA 5000, Australia
- Basil Hetzel Institute for Translational Health Research, Adelaide, SA 5011, Australia
| | - Rosanna Tavella
- School of Medicine, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5000, Australia; (S.P.); (R.T.); (C.Z.); (S.E.); (M.W.); (M.A.)
- Central Adelaide Local Health Network, Adelaide, SA 5000, Australia
- Basil Hetzel Institute for Translational Health Research, Adelaide, SA 5011, Australia
| | - Christopher Zeitz
- School of Medicine, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5000, Australia; (S.P.); (R.T.); (C.Z.); (S.E.); (M.W.); (M.A.)
- Central Adelaide Local Health Network, Adelaide, SA 5000, Australia
| | - Suzanne Edwards
- School of Medicine, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5000, Australia; (S.P.); (R.T.); (C.Z.); (S.E.); (M.W.); (M.A.)
- Basil Hetzel Institute for Translational Health Research, Adelaide, SA 5011, Australia
| | - Matthew Worthley
- School of Medicine, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5000, Australia; (S.P.); (R.T.); (C.Z.); (S.E.); (M.W.); (M.A.)
- Central Adelaide Local Health Network, Adelaide, SA 5000, Australia
| | - Margaret Arstall
- School of Medicine, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5000, Australia; (S.P.); (R.T.); (C.Z.); (S.E.); (M.W.); (M.A.)
- Northern Adelaide Local Health Network, Adelaide, SA 5112, Australia
| | - John F. Beltrame
- School of Medicine, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5000, Australia; (S.P.); (R.T.); (C.Z.); (S.E.); (M.W.); (M.A.)
- Central Adelaide Local Health Network, Adelaide, SA 5000, Australia
- Basil Hetzel Institute for Translational Health Research, Adelaide, SA 5011, Australia
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Kim Y, Clemens EG, Farner JM, Londono-Barbaran A, Grab DJ, Dumler JS. Spotted fever rickettsia-induced microvascular endothelial barrier dysfunction is delayed by the calcium channel blocker benidipine. Biochem Biophys Res Commun 2023; 663:96-103. [PMID: 37121130 PMCID: PMC10362780 DOI: 10.1016/j.bbrc.2023.04.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 04/17/2023] [Indexed: 05/02/2023]
Abstract
The tick-borne bacterium Rickettsia parkeri is an obligate intracellular pathogen that belongs to spotted fever group rickettsia (SFGR). The SFG pathogens are characterized by their ability to infect and rapidly proliferate inside host vascular endothelial cells that eventually result in impairment of vascular endothelium barrier functions. Benidipine, a wide range dihydropyridine calcium channel blocker, is used to prevent and treat cardiovascular diseases. In this study, we tested whether benidipine has protective effects against rickettsia-induced microvascular endothelial cell barrier dysfunction in vitro. We utilized an in vitro vascular model consisting of transformed human brain microvascular endothelial cells (tHBMECs) and continuously monitored transendothelial electric resistance (TEER) across the cell monolayer. We found that during the late stages of infection when we observed TEER decrease and when there was a gradual increase of the cytoplasmic [Ca2+], benidipine prevented these rickettsia-induced effects. In contrast, nifedipine, another cardiovascular dihydropyridine channel blocker specific for L-type Ca2+ channels, did not prevent R. parkeri-induced drop of TEER. Additionally, neither drug was bactericidal. These data suggest that growth of R. parkeri inside endothelial cells is associated with impairment of endothelial cell monolayer integrity due to Ca2+ flooding through specific, benidipine-sensitive T- or N/Q-type Ca2+ channels but not through nifedipine-sensitive L-type Ca2+ channels. Further study will be required to discern the exact nature of the Ca2+ channels and Ca2+ transporting system(s) involved, any contributions of the pathogen toward this process, as well as the suitability of benidipine and new dihydropyridine derivatives as complimentary therapeutic drugs against Rickettsia-induced vascular failure.
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Affiliation(s)
- Yuri Kim
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA; Uniformed Services of the Health Sciences, Department of Pathology, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - Emily G Clemens
- Uniformed Services of the Health Sciences, Department of Pathology, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - Jennifer M Farner
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA; Uniformed Services of the Health Sciences, Department of Pathology, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - Andres Londono-Barbaran
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA; Uniformed Services of the Health Sciences, Department of Pathology, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - Dennis J Grab
- Uniformed Services of the Health Sciences, Department of Pathology, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - J Stephen Dumler
- Uniformed Services of the Health Sciences, Department of Pathology, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
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Fabin N, Bergami M, Cenko E, Bugiardini R, Manfrini O. The Role of Vasospasm and Microcirculatory Dysfunction in Fluoropyrimidine-Induced Ischemic Heart Disease. J Clin Med 2022; 11:jcm11051244. [PMID: 35268333 PMCID: PMC8910913 DOI: 10.3390/jcm11051244] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/13/2022] [Accepted: 02/23/2022] [Indexed: 12/10/2022] Open
Abstract
Cardiovascular diseases and cancer are the leading cause of morbidity and mortality globally. Cardiotoxicity from chemotherapeutic agents results in substantial morbidity and mortality in cancer survivors and patients with active cancer. Cardiotoxicity induced by 5-fluorouracil (5-FU) has been well established, yet its incidence, mechanisms, and manifestation remain poorly defined. Ischemia secondary to coronary artery vasospasm is thought to be the most frequent cardiotoxic effect of 5-FU. The available evidence of 5-FU-induced epicardial coronary artery spasm and coronary microvascular dysfunction suggests that endothelial dysfunction or primary vascular smooth muscle dysfunction (an endothelial-independent mechanism) are the possible contributing factors to this form of cardiotoxicity. In patients with 5-FU-related coronary artery vasospasm, termination of chemotherapy and administration of nitrates or calcium channel blockers may improve ischemic symptoms. However, there are variable results after administration of nitrates or calcium channel blockers in patients treated with 5-FU presumed to have myocardial ischemia, suggesting mechanisms other than impaired vasodilatory response. Clinicians should investigate whether chest pain and ECG changes can reasonably be attributed to 5-FU-induced cardiotoxicity. More prospective data and clinical randomized trials are required to understand and mitigate potentially adverse outcomes from 5-FU-induced cardiotoxicity.
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Abdo AI, Tran HB, Hodge S, Beltrame JF, Zalewski PD. Zinc Homeostasis Alters Zinc Transporter Protein Expression in Vascular Endothelial and Smooth Muscle Cells. Biol Trace Elem Res 2021; 199:2158-2171. [PMID: 32776265 DOI: 10.1007/s12011-020-02328-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/03/2020] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Zinc is an important essential micronutrient with anti-oxidative and anti-inflammatory properties in humans. The role of zinc in signalling has been characterized in the nervous, endocrine, gastrointestinal, renal and reproductive systems. Relatively little is known regarding its role in the vascular system, but the role of zinc homeostasis in augmenting vascular health and vasorelaxation is emerging. Zinc transport proteins are integral to the protective function of zinc, but knowledge of their expression in vascular endothelial and smooth muscle cells is lacking. METHODOLOGY Human coronary artery endothelial cells and pulmonary artery smooth muscle cells were assessed for gene expression (RT-PCR) of SLC39A (ZIP), SLC30A (ZnT) and metallothionein (MT) families of Zn transporters and storage proteins. Protein expression (fluorescence confocal microscopy) was then analysed for the proteins of interest that changed mRNA expression: ZIP2, ZIP12, ZnT1, ZnT2 and MT1/2. RESULTS Endothelial and smooth muscle cell mRNA expression of ZnT1, ZnT2 and MT1 was significantly downregulated by low and high Zn conditions, while ZIP2 and ZIP12 expression was induced by Zn depletion with the Zn chelator, TPEN. Changes in gene expression were consistent with protein expression levels for ZIP2, ZIP12 and MT1, where ZIP2 was localized to intracellular bodies and ZIP12 to lamellipodia. CONCLUSION Vascular endothelial and smooth muscle cells actively regulate specific Zn transport and metallothionein gene and protein expressions to achieve Zn homeostasis.
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Affiliation(s)
- Adrian I Abdo
- Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, 28 Woodville Rd, Woodville South, SA, 5011, Australia.
- Faculty of Health and Medical Sciences, University of Adelaide, 4 North Terrace, Adelaide, SA, 5000, Australia.
| | - Hai Bac Tran
- Faculty of Health and Medical Sciences, University of Adelaide, 4 North Terrace, Adelaide, SA, 5000, Australia
| | - Sandra Hodge
- Faculty of Health and Medical Sciences, University of Adelaide, 4 North Terrace, Adelaide, SA, 5000, Australia
| | - John F Beltrame
- Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, 28 Woodville Rd, Woodville South, SA, 5011, Australia
- Faculty of Health and Medical Sciences, University of Adelaide, 4 North Terrace, Adelaide, SA, 5000, Australia
| | - Peter D Zalewski
- Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, 28 Woodville Rd, Woodville South, SA, 5011, Australia.
- Faculty of Health and Medical Sciences, University of Adelaide, 4 North Terrace, Adelaide, SA, 5000, Australia.
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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.
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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
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Iqbal H, Verma AK, Yadav P, Alam S, Shafiq M, Mishra D, Khan F, Hanif K, Negi AS, Chanda D. Antihypertensive Effect of a Novel Angiotensin II Receptor Blocker Fluorophenyl Benzimidazole: Contribution of cGMP, Voltage-dependent Calcium Channels, and BK Ca Channels to Vasorelaxant Mechanisms. Front Pharmacol 2021; 12:611109. [PMID: 33859561 PMCID: PMC8042648 DOI: 10.3389/fphar.2021.611109] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/09/2021] [Indexed: 12/03/2022] Open
Abstract
Background: The current study presents the novel angiotensin II receptor blocker fluorophenyl benzimidazole (FPD) as an antihypertensive agent in the SHR model of hypertension. We investigated the role of cGMP, voltage-dependent L-type calcium channels, and BKCa channels in the vasorelaxant mechanisms of FPD in the rat superior mesenteric artery. Methods: The antihypertensive effect of FPD was examined using an invasive technique measuring blood pressure in SHR animals. Using a myograph, tension measurement was completed in the superior mesenteric artery to elucidate the mechanisms of vasorelaxation involving AT1 receptors, the NO/cGMP pathway, L-type calcium channels, and BKCa channels. Ion flux (Ca2+, K+) studies were conducted in aortic smooth muscle cells. Putative targets proteins were determined by in silico docking studies. A safety evaluation of FPD was carried out using Swiss albino mice. Results: FPD significantly decreased blood pressure in SHR. It relaxed superior mesenteric arteries in a concentration-dependent manner and significantly inhibited angiotensin II-induced contraction. The relaxation response was also mediated by an increase in tissue cGMP levels, inhibition of L-type calcium channels, and the opening of BKCa channels. FPD further enhanced efflux of K+ and inhibited Bay K8644-stimulated Ca2+ influx in aortic smooth muscle cells and docked well in an in silico study with the targets. It was well tolerated in the toxicity study. Conclusion: The present study reports the antihypertensive activity of novel AT-1 receptor blocker FPD at 50 and 100 mg kg−1 with cGMP, L-type calcium channels, and BKCa channels as putative targets of vasorelaxation, and was found safe in oral toxicity.
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Affiliation(s)
- Hina Iqbal
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Amit Kumar Verma
- Phytochemistry Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Pankaj Yadav
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Sarfaraz Alam
- Computational Biology Lab, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Mohammad Shafiq
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Divya Mishra
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Feroz Khan
- Computational Biology Lab, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Kashif Hanif
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Arvind Singh Negi
- Phytochemistry Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Debabrata Chanda
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
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Abstract
Vascular smooth muscle cells (VSMCs) of small peripheral arteries contribute to blood pressure control by adapting their contractile state. These adaptations depend on the VSMC cytosolic Ca2+ concentration, regulated by complex local elementary Ca2+ signaling pathways. Ca2+ sparks represent local, transient, rapid calcium release events from a cluster of ryanodine receptors (RyRs) in the sarcoplasmic reticulum. In arterial SMCs, Ca2+ sparks activate nearby calcium-dependent potassium channels, cause membrane hyperpolarization and thus decrease the global intracellular [Ca2+] to oppose vasoconstriction. Arterial SMC Cav1.2 L-type channels regulate intracellular calcium stores content, which in turn modulates calcium efflux through RyRs. Cav3.2 T-type channels contribute to a minor extend to Ca2+ spark generation in certain types of arteries. Their localization within cell membrane caveolae is essential. We summarize present data on local elementary calcium signaling (Ca2+ sparks) in arterial SMCs with focus on RyR isoforms, large-conductance calcium-dependent potassium (BKCa) channels, and cell membrane-bound calcium channels (Cav1.2 and Cav3.2), particularly in caveolar microdomains.
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Affiliation(s)
- Gang Fan
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Yingqiu Cui
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Maik Gollasch
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany
| | - Mario Kassmann
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany
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Deficiency of T-type voltage-gated calcium channels results in attenuated weight gain and improved endothelium-dependent dilatation of resistance vessels induced by a high-fat diet in mice. J Physiol Biochem 2020; 76:135-145. [PMID: 32016773 DOI: 10.1007/s13105-020-00728-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 01/21/2020] [Indexed: 01/13/2023]
Abstract
The deletion of T-type Cav3.1 channels may reduce high-fat diet (HFD)-induced weight gain, which correlates positively with obesity and endothelial dysfunction. Therefore, experiments were designed to study the involvement of T-type Cav3.1 channels in HFD-induced endothelial dysfunction in mice. Wildtype (WT) and Cav3.1-/- mice were fed either a normal diet (ND) or an HFD for 8 weeks. Body composition was assessed, and thoracic aortae and mesenteric arteries were harvested for myography to assess endothelium-dependent responses. Changes in intracellular calcium were measured by fluorescence imaging, and behavior was assessed with the open-field test. Cav3.1-/- mice had attenuated HFD-induced weight gain and lower total fat mass compared with WT mice. Cav3.1-/- mice on an HFD had reduced plasma cholesterol levels compared with WT mice on the same diet. Increased feeding efficiency, independent of food intake, was observed in WT mice on an HFD compared with an ND, but no difference in feeding efficiency between diets was observed for Cav3.1-/- mice. Nitric oxide-dependent dilatation was increased in mesenteric arteries of Cav3.1-/- mice compared with WT mice on an HFD, with no difference observed in aortae. No differences in mouse locomotor activity were observed between the experimental groups. Mice on an HFD lacking T-type channels have reduced weight gain, lower total cholesterol levels, and increased dilatation of resistance vessels compared with WT mice on an HFD, suggesting that Cav3.1 deletion protects against endothelial dysfunction in resistance vessels but not in large conduit vessels.
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Ottolini M, Hong K, Sonkusare SK. Calcium signals that determine vascular resistance. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2019; 11:e1448. [PMID: 30884210 PMCID: PMC6688910 DOI: 10.1002/wsbm.1448] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 02/07/2019] [Accepted: 02/14/2019] [Indexed: 12/19/2022]
Abstract
Small arteries in the body control vascular resistance, and therefore, blood pressure and blood flow. Endothelial and smooth muscle cells in the arterial walls respond to various stimuli by altering the vascular resistance on a moment to moment basis. Smooth muscle cells can directly influence arterial diameter by contracting or relaxing, whereas endothelial cells that line the inner walls of the arteries modulate the contractile state of surrounding smooth muscle cells. Cytosolic calcium is a key driver of endothelial and smooth muscle cell functions. Cytosolic calcium can be increased either by calcium release from intracellular stores through IP3 or ryanodine receptors, or the influx of extracellular calcium through ion channels at the cell membrane. Depending on the cell type, spatial localization, source of a calcium signal, and the calcium-sensitive target activated, a particular calcium signal can dilate or constrict the arteries. Calcium signals in the vasculature can be classified into several types based on their source, kinetics, and spatial and temporal properties. The calcium signaling mechanisms in smooth muscle and endothelial cells have been extensively studied in the native or freshly isolated cells, therefore, this review is limited to the discussions of studies in native or freshly isolated cells. This article is categorized under: Biological Mechanisms > Cell Signaling Laboratory Methods and Technologies > Imaging Models of Systems Properties and Processes > Mechanistic Models.
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Affiliation(s)
- Matteo Ottolini
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
| | - Kwangseok Hong
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Physical Education, Chung-Ang University, Seoul, 06974, South Korea
| | - Swapnil K. Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
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Zhou S, Tao M, Wang Y, Wang L, Xie L, Chen J, Zhao Y, Liu Y, Zhang H, Ou N, Wang G, Shao F, Aa J. Effects of CYP3A4*1G and CYP3A5*3 polymorphisms on pharmacokinetics of tylerdipine hydrochloride in healthy Chinese subjects. Xenobiotica 2018. [PMID: 29521134 DOI: 10.1080/00498254.2018.1447711] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The aim of this analysis was to explore the influence of CYP3A4*1G and CYP3A5*3 polymorphisms on the pharmacokinetics of tylerdipine in healthy Chinese subjects. A total of 64 and 63 healthy Chinese subjects were included and identified as the genotypes of CYP3A4*1G and CYP3A5*3, respectively. Plasma samples were collected for up to 120 h post-dose to characterize the pharmacokinetic profile following single oral dose of the drug (5, 15, 20, 25 and 30 mg). Plasma levels were measured by a high-performance liquid chromatography-mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated using non-compartmental method. The maximum concentration (Cmax) and the area under the curve (AUC0-24 h) were all corrected by the dose given. In the wild-type group, the mean dose-corrected AUC0-24 h was 1.35-fold larger than in CYP3A4*1G carriers (p = .018). Among the three CYP3A5 genotypes, there showed significantly difference (p = .008) in the t1/2, but no significant difference was observed for the AUC0-24 h and Cmax. In subjects with the CYP3A5*3/*3 genotype, the mean t1/2 was 1.35-fold higher than in CYP3A5*1/*1 group (p = .007). And the t1/2 in CYP3A5*3 carriers also was 1.32-fold higher than in the wild-type group (p = .004). CYP3A4*1G and CYP3A5*3 polymorphisms may influence tylerdipine pharmacokinetic in healthy Chinese subjects.
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Affiliation(s)
- Sufeng Zhou
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Mingxue Tao
- b Key Laboratory of Drug Metabolism and Pharmacokinetics , China Pharmaceutical University , Nanjing , China
| | - Yuanyuan Wang
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Lu Wang
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Lijun Xie
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Juan Chen
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Yuqing Zhao
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Yun Liu
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Hongwen Zhang
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Ning Ou
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Guangji Wang
- b Key Laboratory of Drug Metabolism and Pharmacokinetics , China Pharmaceutical University , Nanjing , China
| | - Feng Shao
- a Phase I Clinical Trial Unit , The First Affiliated Hospital of Nanjing Medical University , Nanjing , China
| | - Jiye Aa
- b Key Laboratory of Drug Metabolism and Pharmacokinetics , China Pharmaceutical University , Nanjing , China
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Regional Heterogeneity in the Regulation of Vasoconstriction in Arteries and Its Role in Vascular Mechanics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1097:105-128. [PMID: 30315542 DOI: 10.1007/978-3-319-96445-4_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Vasoconstriction and vasodilation play important roles in the circulatory system and can be regulated through different pathways that depend on myriad biomolecules. These different pathways reflect the various functions of smooth muscle cell (SMC) contractility within the different regions of the arterial tree and how they contribute to both the mechanics and the mechanobiology. Here, we review the primary regulatory pathways involved in SMC contractility and highlight their regional differences in elastic, muscular, and resistance arteries. In this way, one can begin to assess how these properties affect important biomechanical and mechanobiological functions in the circulatory system in health and disease.
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Thuesen AD, Andersen K, Lyngsø KS, Burton M, Brasch-Andersen C, Vanhoutte PM, Hansen PBL. Deletion of T-type calcium channels Cav3.1 or Cav3.2 attenuates endothelial dysfunction in aging mice. Pflugers Arch 2017; 470:355-365. [DOI: 10.1007/s00424-017-2068-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/10/2017] [Accepted: 09/13/2017] [Indexed: 12/26/2022]
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Detremmerie C, Vanhoutte PM, Leung S. Biased activity of soluble guanylyl cyclase: the Janus face of thymoquinone. Acta Pharm Sin B 2017; 7:401-408. [PMID: 28752025 PMCID: PMC5518662 DOI: 10.1016/j.apsb.2017.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 06/13/2017] [Indexed: 11/28/2022] Open
Abstract
The natural compound thymoquinone, extracted from Nigella sativa (black cumin), is widely used in humans for its anti-oxidative properties. Thymoquinone is known for its acute endothelium-independent vasodilator effects in isolated rat aortae and pulmonary arteries, depending in part on activation of adenosine triphosphate-sensitive potassium channels and inhibition of voltage-dependent calcium channels. The compound also improves endothelial dysfunction in mesenteric arteries of ageing rodents and in aortae of rabbits treated with pyrogallol, by inhibiting oxidative stress. Serendipitously, thymoquinone was found to augment contractions in isolated arteries with endothelium of both rats and pigs. The endothelium-dependent augmentation it causes counterintuitively depends on biased activation of soluble guanylyl cyclase (sGC) producing inosine 3',5'-cyclic monophosphate (cyclic IMP) rather than guanosine 3',5'-cyclic monophosphate. This phenomenon shows a striking mechanistic similarity to the hypoxic augmentation previously observed in porcine coronary arteries. The cyclic IMP preferentially produced under thymoquinone exposure causes an increased contractility of arterial smooth muscle by interfering with calcium homeostasis. This brief review summarizes the vascular pharmacology of thymoquinone, focussing in particular on how the compound causes endothelium-dependent contractions by biasing the activity of sGC.
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Thuesen AD, Lyngsø KS, Rasmussen L, Stubbe J, Skøtt O, Poulsen FR, Pedersen CB, Rasmussen LM, Hansen PBL. P/Q-type and T-type voltage-gated calcium channels are involved in the contraction of mammary and brain blood vessels from hypertensive patients. Acta Physiol (Oxf) 2017; 219:640-651. [PMID: 27273014 DOI: 10.1111/apha.12732] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 03/21/2016] [Accepted: 06/01/2016] [Indexed: 12/12/2022]
Abstract
AIM Calcium channel blockers are widely used in cardiovascular diseases. Besides L-type channels, T- and P/Q-type calcium channels are involved in the contraction of human renal blood vessels. It was hypothesized that T- and P/Q-type channels are involved in the contraction of human brain and mammary blood vessels. METHODS Internal mammary arteries from bypass surgery patients and cerebral arterioles from patients with brain tumours with and without hypertension were tested in a myograph and perfusion set-up. PCR and immunohistochemistry were performed on isolated blood vessels. RESULTS The P/Q-type antagonist ω-agatoxin IVA (10-8 mol L-1 ) and the T-type calcium blocker mibefradil (10-7 mol L-1 ) inhibited KCl depolarization-induced contraction in mammary arteries from hypertensive patients with no effect on blood vessels from normotensive patients. ω-Agatoxin IVA decreased contraction in cerebral arterioles from hypertensive patients. L-type blocker nifedipine abolished the contraction in mammary arteries. PCR analysis showed expression of P/Q-type (Cav 2.1), T-type (Cav 3.1 and Cav 3.2) and L-type (Cav 1.2) calcium channels in mammary and cerebral arteries. Immunohistochemical labelling of mammary and cerebral arteries revealed the presence of Cav 2.1 in endothelial and smooth muscle cells. Cav 3.1 was also detected in mammary arteries. CONCLUSION P/Q- and T-type Cav are present in human internal mammary arteries and in cerebral penetrating arterioles. P/Q- and T-type calcium channels are involved in the contraction of mammary arteries from hypertensive patients but not from normotensive patients. Furthermore, in cerebral arterioles P/Q-type channels importance was restricted to hypertensive patients might lead to that T- and P/Q-type channels could be a new target in hypertensive patients.
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Affiliation(s)
- A. D. Thuesen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - K. S. Lyngsø
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - L. Rasmussen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - J. Stubbe
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - O. Skøtt
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - F. R. Poulsen
- Department of Neurosurgery; Odense University Hospital; Odense Denmark
- Clinical Institute; University of Southern Denmark; Odense Denmark
| | - C. B. Pedersen
- Department of Neurosurgery; Odense University Hospital; Odense Denmark
| | - L. M. Rasmussen
- Clinical Institute; University of Southern Denmark; Odense Denmark
- Department of Clinical Biochemistry and Pharmacology; Centre for Individualized Medicine in Arterial Diseases; Odense University Hospital; Odense Denmark
| | - P. B. L. Hansen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
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15
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Tamargo J. [New calcium channel blockers for the treatment of hypertension]. HIPERTENSION Y RIESGO VASCULAR 2017; 34 Suppl 2:5-8. [PMID: 29908667 DOI: 10.1016/s1889-1837(18)30067-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
L-type voltage-gated calcium channels play a key role in the regulation of arterial vascular smooth muscle tone and blood pressure levels and L-type calcium channel blockers (CCBs) are widely used antihypertensive drugs. Additionally, T-type channels regulate vascular tone in small-resistance vessels and renin and aldosterone secretion, and N-type channels, expressed in sympathetic nerve terminals, regulate the release of neurotransmitters. As compared with L-type CCBs, L/N-and L/T-type CCBs decreased intraglomerular pressure, improved renal hemodynamics and provided a greater decrease in proteinuria even in patients already treated with renin-angiotensin-aldosterone inhibitors. Thus, dual L/N-and L/T-type CCBs may exhibit therapeutic advantages over L-type blockers in hypertensive patients with chronic kidney disease. However, further large-scale, long-term comparative trials are needed to confirm that these differences translate into an improvement in clinical outcomes. © 2017 SEHLELHA. Published by Elsevier España, S.L.U. All rights reserved.
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Affiliation(s)
- J Tamargo
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, España.
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Tamargo J, Ruilope LM. Investigational calcium channel blockers for the treatment of hypertension. Expert Opin Investig Drugs 2016; 25:1295-1309. [DOI: 10.1080/13543784.2016.1241764] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- J Tamargo
- Department of Pharmacology, School of Medicine, Instituto de Investigación Sanitaria Gregorio Marañón, Universidad Complutense, Madrid, Spain. CIBER of Cardiovascular Diseases
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Mikkelsen MF, Björling K, Jensen LJ. Age-dependent impact of Ca V 3.2 T-type calcium channel deletion on myogenic tone and flow-mediated vasodilatation in small arteries. J Physiol 2016; 594:5881-5898. [PMID: 26752249 PMCID: PMC5063926 DOI: 10.1113/jp271470] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/18/2015] [Indexed: 01/14/2023] Open
Abstract
KEY POINTS Blood pressure and flow exert mechanical forces on the walls of small arteries, which are detected by the endothelial and smooth muscle cells, and lead to regulation of the diameter (basal tone) of an artery. CaV 3.2 T-type calcium channels are expressed in the wall of small arteries, although their function remains poorly understood because of the low specificity of T-type blockers. We used mice deficient in CaV 3.2 channels to study their role in pressure- and flow-dependent tone regulation and the possible impact of ageing on this role. In young mice, CaV 3.2 channels oppose pressure-induced vasoconstriction and participate in endothelium-dependent, flow-mediated dilatation. These effects were not seen in mature adult mice. The results of the present study demonstrate an age-dependent impact of CaV 3.2 T-type calcium channel deletion in rodents and suggest that the loss of CaV 3.2 channel function leads to more constricted arteries, which is a risk factor for cardiovascular disease. ABSTRACT The myogenic response and flow-mediated vasodilatation are important regulators of local blood perfusion and total peripheral resistance, and are known to entail a calcium influx into vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), respectively. CaV 3.2 T-type calcium channels are expressed in both VSMCs and ECs of small arteries. The T-type channels are important drug targets but, as a result of the lack of specific antagonists, our understanding of the role of CaV 3.2 channels in vasomotor tone at various ages is scarce. We evaluated the myogenic response, flow-mediated vasodilatation, structural remodelling and mRNA + protein expression in small mesenteric arteries from CaV 3.2 knockout (CaV 3.2KO) vs. wild-type mice at a young vs. mature adult age. In young mice only, deletion of CaV 3.2 led to an enhanced myogenic response and a ∼50% reduction of flow-mediated vasodilatation. Ni2+ had both CaV 3.2-dependent and independent effects. No changes in mRNA expression of several important K+ and Ca2+ channel genes were induced by CaV 3.2KO However, the expression of the other T-type channel isoform (CaV 3.1) was reduced at the mRNA and protein level in mature adult compared to young wild-type arteries. The results of the present study demonstrate the important roles of the CaV 3.2 T-type calcium channels in myogenic tone and flow-mediated vasodilatation that disappear with ageing. Because increased arterial tone is a risk factor for cardiovascular disease, we conclude that CaV 3.2 channels, by modulating pressure- and flow-mediated vasomotor responses to prevent excess arterial tone, protect against cardiovascular disease.
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Affiliation(s)
- Miriam F Mikkelsen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Karl Björling
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars Jørn Jensen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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18
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Detremmerie CM, Chen Z, Li Z, Alkharfy KM, Leung SWS, Xu A, Gao Y, Vanhoutte PM. Endothelium-Dependent Contractions of Isolated Arteries to Thymoquinone Require Biased Activity of Soluble Guanylyl Cyclase with Subsequent Cyclic IMP Production. J Pharmacol Exp Ther 2016; 358:558-68. [PMID: 27335436 DOI: 10.1124/jpet.116.234153] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 06/15/2016] [Indexed: 11/22/2022] Open
Abstract
Preliminary experiments on isolated rat arteries demonstrated that thymoquinone, a compound widely used for its antioxidant properties and believed to facilitate endothelium-dependent relaxations, as a matter of fact caused endothelium-dependent contractions. The present experiments were designed to determine the mechanisms underlying this unexpected response. Isometric tension was measured in rings (with and without endothelium) of rat mesenteric arteries and aortae and of porcine coronary arteries. Precontracted preparations were exposed to increasing concentrations of thymoquinone, which caused concentration-dependent, sustained further increases in tension (augmentations) that were prevented by endothelium removal, Nω-nitro-L-arginine methyl ester [L-NAME; nitric oxide (NO) synthase inhibitor], and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; soluble guanylyl cyclase [sGC] inhibitor). In L-NAME-treated rings, the NO-donor diethylenetriamine NONOate restored the thymoquinone-induced augmentations; 5-[1-(phenylmethyl)-1H-indazol-3-yl]-2-furanmethanol (sGC activator) and cyclic IMP (cIMP) caused similar restorations. By contrast, in ODQ-treated preparations, the cell-permeable cGMP analog did not restore the augmentation by thymoquinone. The compound augmented the content (measured with ultra-high performance liquid chromatography-tandem mass spectrometry) of cIMP, but not that of cGMP; these increases in cIMP content were prevented by endothelium removal, L-NAME, and ODQ. The augmentation of contractions caused by thymoquinone was prevented in porcine arteries, but not in rat arteries, by 1-(5-isoquinolinylsulfonyl)homopiperazine dihydrochloride and trans-4-[(1R)-1-aminoethyl]-N-4-pyridinylcyclohexanecarboxamide dihydrochloride (Rho-kinase inhibitors); in the latter, but not in the former, it was reduced by 3,5-dichloro-N-[[(1α,5α,6-exo,6α)-3-(3,3-dimethylbutyl)-3-azabicyclo[3.1.0]hex-6-yl]methyl]-benzamide hydrochloride (T-type calcium channel inhibitor), demonstrating species/vascular bed differences in the impact of cIMP on calcium handling. Thymoquinone is the first pharmacological agent that causes endothelium-dependent augmentation of contractions of isolated arteries, which requires endothelium-derived NO and biased sGC activation, resulting in the augmented production of cIMP favoring the contractile process.
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Affiliation(s)
- Charlotte M Detremmerie
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
| | - Zhengju Chen
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
| | - Zhuoming Li
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
| | - Khalid M Alkharfy
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
| | - Susan W S Leung
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
| | - Aimin Xu
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
| | - Yuansheng Gao
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
| | - Paul M Vanhoutte
- Department of Pharmacology and Pharmacy and State Key Laboratory for Pharmaceutical Biotechnology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China (C.M.D., Z.L., S.W.S.L., A.X., P.M.V.); Department of Clinical Pharmacy, King Saud University, Saudi Arabia (K.M.A.) and Department of Physiology and Pathophysiology, Peking University Health Science Centre, Beijing, China (Z.C., Y.G.)
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19
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Tavella R, Cutri N, Tucker G, Adams R, Spertus J, Beltrame JF. Natural history of patients with insignificant coronary artery disease. EUROPEAN HEART JOURNAL. QUALITY OF CARE & CLINICAL OUTCOMES 2016; 2:117-124. [DOI: 10.1093/ehjqcco/qcv034] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Indexed: 02/02/2023]
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20
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Banciu DD, Banciu A, Radu BM. Electrophysiological Features of Telocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 913:287-302. [PMID: 27796895 DOI: 10.1007/978-981-10-1061-3_19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Telocytes (TCs) are interstitial cells described in multiple structures, including the gastrointestinal tract, respiratory tract, urinary tract, uterus, and heart. Several studies have indicated the possibility that TCs are involved in the pacemaker potential in these organs. It is supposed that TCs are interacting with the neighboring muscular cells and their network contributes to the initiation and propagation of the electrical potentials. In order to understand the contribution of TCs to various excitability mechanisms, it is necessary to analyze the plasma membrane proteins (e.g., ion channels) functionally expressed in these cells. So far, potassium, calcium, and chloride currents, but not sodium currents, have been described in TCs in primary cell culture from different tissues. Moreover, TCs have been described as sensors for mechanical stimuli (e.g., contraction, extension, etc.). In conclusion, TCs might play an essential role in gastrointestinal peristalsis, in respiration, in pregnant uterus contraction, or in miction, but further highlighting studies are necessary to understand the molecular mechanisms and the cell-cell interactions by which TCs contribute to the tissue excitability and pacemaker potentials initiation/propagation.
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Affiliation(s)
- Daniel Dumitru Banciu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Bucharest, 050095, Romania
| | - Adela Banciu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Bucharest, 050095, Romania
| | - Beatrice Mihaela Radu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Bucharest, 050095, Romania. .,Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 8, Verona, 37134, Italy.
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Martinsen A, Dessy C, Morel N. Regulation of calcium channels in smooth muscle: new insights into the role of myosin light chain kinase. Channels (Austin) 2015; 8:402-13. [PMID: 25483583 DOI: 10.4161/19336950.2014.950537] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Smooth muscle myosin light chain kinase (MLCK) plays a crucial role in artery contraction, which regulates blood pressure and blood flow distribution. In addition to this role, MLCK contributes to Ca(2+) flux regulation in vascular smooth muscle (VSM) and in non-muscle cells, where cytoskeleton has been suggested to help Ca(2+) channels trafficking. This conclusion is based on the use of pharmacological inhibitors of MLCK and molecular and cellular techniques developed to down-regulate the enzyme. Dissimilarities have been observed between cells and whole tissues, as well as between large conductance and small resistance arteries. A differential expression in MLCK and ion channels (either voltage-dependent Ca(2+) channels or non-selective cationic channels) could account for these observations, and is in line with the functional properties of the arteries. A potential involvement of MLCK in the pathways modulating Ca(2+) entry in VSM is described in the present review.
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Key Words
- CaM, calmodulin
- ER, endoplasmic reticulum
- MLCK, myosin light chain kinase
- Myosin light chain kinase
- ROC, receptor-operated Ca2+ (channel)
- SMC, smooth muscle cell
- SOC, store-operated Ca2+ (channel)
- SR, sarcoplasmic reticulum
- TRP
- TRP, transient receptor potential (channel)
- VOC, voltage-operated Ca2+ (channel)
- VSM, vascular smooth muscle
- VSMC, vascular smooth muscle cell
- [Ca2+]cyt, cytosolic Ca2+ concentration
- siRNA, small interfering RNA
- vascular smooth muscle
- voltage-dependent calcium channels
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Affiliation(s)
- A Martinsen
- a Cell physiology; IoNS; UCLouvain ; Brussels , Belgium
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Hansen PBL. Functional importance of T-type voltage-gated calcium channels in the cardiovascular and renal system: news from the world of knockout mice. Am J Physiol Regul Integr Comp Physiol 2015; 308:R227-37. [DOI: 10.1152/ajpregu.00276.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Over the years, it has been discussed whether T-type calcium channels Cav3 play a role in the cardiovascular and renal system. T-type channels have been reported to play an important role in renal hemodynamics, contractility of resistance vessels, and pacemaker activity in the heart. However, the lack of highly specific blockers cast doubt on the conclusions. As new T-type channel antagonists are being designed, the roles of T-type channels in cardiovascular and renal pathology need to be elucidated before T-type blockers can be clinically useful. Two types of T-type channels, Cav3.1 and Cav3.2, are expressed in blood vessels, the kidney, and the heart. Studies with gene-deficient mice have provided a way to investigate the Cav3.1 and Cav3.2 channels and their role in the cardiovascular system. This review discusses the results from these knockout mice. Evaluation of the literature leads to the conclusion that Cav3.1 and Cav3.2 channels have important, but different, functions in mice. T-type Cav3.1 channels affect heart rate, whereas Cav3.2 channels are involved in cardiac hypertrophy. In the vascular system, Cav3.2 activation leads to dilation of blood vessels, whereas Cav3.1 channels are mainly suggested to affect constriction. The Cav3.1 channel is also involved in neointima formation following vascular damage. In the kidney, Cav3.1 regulates plasma flow and Cav3.2 plays a role setting glomerular filtration rate. In conclusion, Cav3.1 and Cav3.2 are new therapeutic targets in several cardiovascular pathologies, but the use of T-type blockers should be specifically directed to the disease and to the channel subtype.
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Affiliation(s)
- Pernille B. L. Hansen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
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23
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Harraz OF, Abd El-Rahman RR, Bigdely-Shamloo K, Wilson SM, Brett SE, Romero M, Gonzales AL, Earley S, Vigmond EJ, Nygren A, Menon BK, Mufti RE, Watson T, Starreveld Y, Furstenhaupt T, Muellerleile PR, Kurjiaka DT, Kyle BD, Braun AP, Welsh DG. Ca(V)3.2 channels and the induction of negative feedback in cerebral arteries. Circ Res 2014; 115:650-61. [PMID: 25085940 DOI: 10.1161/circresaha.114.304056] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE T-type (CaV3.1/CaV3.2) Ca(2+) channels are expressed in rat cerebral arterial smooth muscle. Although present, their functional significance remains uncertain with findings pointing to a variety of roles. OBJECTIVE This study tested whether CaV3.2 channels mediate a negative feedback response by triggering Ca(2+) sparks, discrete events that initiate arterial hyperpolarization by activating large-conductance Ca(2+)-activated K(+) channels. METHODS AND RESULTS Micromolar Ni(2+), an agent that selectively blocks CaV3.2 but not CaV1.2/CaV3.1, was first shown to depolarize/constrict pressurized rat cerebral arteries; no effect was observed in CaV3.2(-/-) arteries. Structural analysis using 3-dimensional tomography, immunolabeling, and a proximity ligation assay next revealed the existence of microdomains in cerebral arterial smooth muscle which comprised sarcoplasmic reticulum and caveolae. Within these discrete structures, CaV3.2 and ryanodine receptor resided in close apposition to one another. Computational modeling revealed that Ca(2+) influx through CaV3.2 could repetitively activate ryanodine receptor, inducing discrete Ca(2+)-induced Ca(2+) release events in a voltage-dependent manner. In keeping with theoretical observations, rapid Ca(2+) imaging and perforated patch clamp electrophysiology demonstrated that Ni(2+) suppressed Ca(2+) sparks and consequently spontaneous transient outward K(+) currents, large-conductance Ca(2+)-activated K(+) channel mediated events. Additional functional work on pressurized arteries noted that paxilline, a large-conductance Ca(2+)-activated K(+) channel inhibitor, elicited arterial constriction equivalent, and not additive, to Ni(2+). Key experiments on human cerebral arteries indicate that CaV3.2 is present and drives a comparable response to moderate constriction. CONCLUSIONS These findings indicate for the first time that CaV3.2 channels localize to discrete microdomains and drive ryanodine receptor-mediated Ca(2+) sparks, enabling large-conductance Ca(2+)-activated K(+) channel activation, hyperpolarization, and attenuation of cerebral arterial constriction.
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Affiliation(s)
- Osama F Harraz
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Rasha R Abd El-Rahman
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Kamran Bigdely-Shamloo
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Sean M Wilson
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Suzanne E Brett
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Monica Romero
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Albert L Gonzales
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Scott Earley
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Edward J Vigmond
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Anders Nygren
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Bijoy K Menon
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Rania E Mufti
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Tim Watson
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Yves Starreveld
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Tobias Furstenhaupt
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Philip R Muellerleile
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - David T Kurjiaka
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Barry D Kyle
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Andrew P Braun
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.)
| | - Donald G Welsh
- From the Department of Physiology and Pharmacology, Hotchkiss Brain and Libin Cardiovascular Institutes (O.F.H., R.R.A.E.-R., K.B.-S., S.E.B., R.E.M., B.D.K., A.P.B., D.G.W.), Department of Electrical and Computer Engineering (K.B.-S., E.J.V., A.N.), Department of Clinical Neurosciences (B.K.M., T.W., Y.S.), and Microscopy Imaging Facility (T.F.), University of Calgary, Calgary, Alberta, Canada; Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt (O.F.H.); Division of Pharmacology, Loma Linda University, CA (S.M.W., M.R.); Department of Biomedical Sciences, Colorado State University, Fort Collins (A.L.G.); Department of Pharmacology, University of Nevada, Reno (S.E.); LIRYC Institute and Lab IMB, University of Bordeaux, Bordeaux, France (E.J.V.); and Department of Biomedical Sciences, Grand Valley State University, Allendale, MI (P.R.M., D.T.K.). dwelsh@ucalgary
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Chevalier M, Gilbert G, Roux E, Lory P, Marthan R, Savineau JP, Quignard JF. T-type calcium channels are involved in hypoxic pulmonary hypertension. Cardiovasc Res 2014; 103:597-606. [PMID: 25016616 DOI: 10.1093/cvr/cvu166] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
AIMS Pulmonary hypertension (PH) is the main disease of pulmonary circulation. Alteration in calcium homeostasis in pulmonary artery smooth muscle cells (PASMCs) is recognized as a key feature in PH. The present study was undertaken to investigate the involvement of T-type voltage-gated calcium channels (T-VGCCs) in the control of the pulmonary vascular tone and thereby in the development of PH. METHODS AND RESULTS Experiments were conducted in animals (rats and mice) kept 3-4 weeks in either normal (normoxic) or hypoxic environment (hypobaric chamber) to induce chronic hypoxia (CH) PH. In vivo, chronic treatment of CH rats with the T-VGCC blocker, TTA-A2, prevented PH and the associated vascular hyperreactivity, pulmonary arterial remodelling, and right cardiac hypertrophy. Deletion of the Cav3.1 gene (a T-VGCC isoform) protected mice from CH-PH. In vitro, patch-clamp and PCR experiments revealed the presence of T-VGCCs (mainly Cav3.1 and Cav3.2) in PASMCs. Mibefradil, NNC550396, and TTA-A2 inhibited, in a concentration-dependent manner, T-VGCC current, KCl-induced contraction, and PASMC proliferation. CONCLUSION The present study demonstrates that T-VGCCs contribute to intrapulmonary vascular reactivity and is implicated in the development of hypoxic PH. Specific blockers of T-VGCCs may thus prove useful for the therapeutic management of PH.
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Affiliation(s)
- Marc Chevalier
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U 1045, Bordeaux F-33000, France INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, 1045, Bordeaux, France
| | - Guillaume Gilbert
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U 1045, Bordeaux F-33000, France INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, 1045, Bordeaux, France
| | - Etienne Roux
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U 1045, Bordeaux F-33000, France INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, 1045, Bordeaux, France
| | - Philipe Lory
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France
| | - Roger Marthan
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U 1045, Bordeaux F-33000, France INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, 1045, Bordeaux, France CHU Bordeaux, Exploration Fonctionnelle Respiratoire, Bordeaux, France
| | - Jean-Pierre Savineau
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U 1045, Bordeaux F-33000, France INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, 1045, Bordeaux, France
| | - Jean-François Quignard
- Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U 1045, Bordeaux F-33000, France INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, 1045, Bordeaux, France
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Tykocki NR, Wu B, Jackson WF, Watts SW. Divergent signaling mechanisms for venous versus arterial contraction as revealed by endothelin-1. J Vasc Surg 2014; 62:721-33. [PMID: 24726828 DOI: 10.1016/j.jvs.2014.03.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/07/2014] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Venous function is underappreciated in its role in blood pressure determination, a physiologic parameter normally ascribed to changes in arterial function. Significant evidence points to the hormone endothelin-1 (ET-1) as being important to venous contributions to blood pressure. We hypothesized that the artery and vein should similarly depend on the signaling pathways stimulated by ET-1, specifically phospholipase C (PLC) activation. This produces two functional arms of signaling: diacylglycerol (DAG; protein kinase C [PKC] activation) and inositol trisphosphate (IP3) production (intracellular calcium release). METHODS The model was the male Sprague-Dawley rat. Isolated tissue baths were used to measure isometric contraction. Western blot and immunocytochemical analyses measured the magnitude of expression and site of expression, respectively, of IP3 receptors in smooth muscle/tissue. Pharmacologic methods were used to modify PLC activity and signaling elements downstream of PLC (IP3 receptors, PKC). RESULTS ET-1-induced contraction was PLC dependent in both tissues as the PLC inhibitor U-73122 significantly reduced contraction in aorta (86% ± 4% of control; P < .05) and vena cava (49% ± 11% of control; P < .05). However, ET-1-induced contraction was not significantly inhibited by the IP3 receptor inhibitor 2-aminoethoxydiphenylborane (100 μM) in vena cava (82% ± 8% of control; P = .23) but was in the aorta (55% ± 4% of control; P < .05). All three IP3 receptor isoforms were located in venous smooth muscle. IP3 receptors were functional in both tissues as the novel membrane-permeable IP3 analogue (Bt-IP3; 10 μM) contracted aorta and vena cava. Similarly, whereas the PKC inhibitor chelerythrine (10 μM) attenuated ET-1-induced contraction in vena cava and aorta (5% ± 2% and 50% ± 5% of control, respectively; P < .05), only the vena cava contracted to the DAG analogue 1-oleoyl-2-acetyl-sn-glycerol. CONCLUSIONS These findings suggest that ET-1 activates PLC in aorta and vena cava, but vena cava contraction to ET-1 may be largely IP3 independent. Rather, DAG—not IP3—may contribute to contraction to ET-1 in vena cava, in part by activation of PKC. These studies outline a fundamental difference between venous and arterial smooth muscle and further reinforce a heterogeneity of vascular smooth muscle function that could be taken advantage of for therapeutic development.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich.
| | - BinXi Wu
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich
| | - Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Mich
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T-type Ca2+ channels facilitate NO-formation, vasodilatation and NO-mediated modulation of blood pressure. Pflugers Arch 2014; 466:2205-14. [DOI: 10.1007/s00424-014-1492-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 11/28/2022]
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Role of T-type channels in vasomotor function: team player or chameleon? Pflugers Arch 2014; 466:767-79. [PMID: 24482062 DOI: 10.1007/s00424-013-1430-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 12/19/2013] [Indexed: 01/28/2023]
Abstract
Low-voltage-activated T-type calcium channels play an important role in regulating cellular excitability and are implicated in conditions, such as epilepsy and neuropathic pain. T-type channels, especially Cav3.1 and Cav3.2, are also expressed in the vasculature, although patch clamp studies of isolated vascular smooth muscle cells have in general failed to demonstrate these low-voltage-activated calcium currents. By contrast, the channels which are blocked by T-type channel antagonists are high-voltage activated but distinguishable from their L-type counterparts by their T-type biophysical properties and small negative shifts in activation and inactivation voltages. These changes in T-channel properties may result from vascular-specific expression of splice variants of Cav3 genes, particularly in exon 25/26 of the III-IV linker region. Recent physiological studies suggest that T-type channels make a small contribution to vascular tone at low intraluminal pressures, although the relevance of this contribution is unclear. By contrast, these channels play a larger role in vascular tone of small arterioles, which would be expected to function at lower intra-vascular pressures. Upregulation of T-type channel function following decrease in nitric oxide bioavailability and increase in oxidative stress, which occurs during cardiovascular disease, suggests that a more important role could be played by these channels in pathophysiological situations. The ability of T-type channels to be rapidly recruited to the plasma membrane, coupled with their subtype-specific localisation in signalling microdomains where they could modulate the function of calcium-dependent ion channels and pathways, provides a mechanism for rapid up- and downregulation of vasoconstriction. Future investigation into the molecules which govern these changes may illuminate novel targets for the treatment of conditions such as therapy-resistant hypertension and vasospasm.
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Tolerability and pharmacokinetics of ACT-280778, a novel nondihydropyridine dual L/T-type calcium channel blocker: early clinical studies in healthy male subjects using adaptive designs. J Cardiovasc Pharmacol 2013; 63:120-31. [PMID: 24126567 DOI: 10.1097/fjc.0000000000000030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
ACT-280778 is a novel nondihydropyridine dual L/T-type calcium channel blocker. Two clinical studies (AC-067-101 and AC-067-102) were conducted to characterize its safety, tolerability, and pharmacokinetics in healthy male subjects after oral administration of single and multiple doses. Both trials were single-center, randomized, double-blind, placebo-controlled, adaptive design, ascending-dose studies, in which ACT-280778 was administrated as single doses of 2, 5, 15, or 40 mg, or as once-daily doses of 5 or 15 mg for 7 days. Single and multiple doses up to and including 15 mg were well tolerated, and no serious or severe adverse event was reported in either study. A single dose of 40 mg was associated with abnormal electrocardiogram findings resulting in the discontinuation of further treatment at this dose or higher doses. ACT-280778 was rapidly absorbed, and larger than dose-proportional increases of the maximum plasma concentration and area under the plasma concentration-time curve were observed. Food intake delayed the time to maximum plasma concentration and doubled exposure. Urinary excretion of unchanged ACT-280778 was negligible, and accumulation at steady state was modest. Overall, pharmacokinetic and tolerability profiles of ACT-280778 observed in these 2 studies warranted further evaluation of ACT-280778 in a proof-of-concept study in patients with hypertension.
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Senadheera S, Bertrand PP, Grayson TH, Leader L, Tare M, Murphy TV, Sandow SL. Enhanced contractility in pregnancy is associated with augmented TRPC3, L-type, and T-type voltage-dependent calcium channel function in rat uterine radial artery. Am J Physiol Regul Integr Comp Physiol 2013; 305:R917-26. [DOI: 10.1152/ajpregu.00225.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In pregnancy, α-adrenoceptor-mediated vasoconstriction is augmented in uterine radial arteries and is accompanied by underlying changes in smooth muscle (SM) Ca2+ activity. This study aims to determine the Ca2+ entry channels associated with altered vasoconstriction in pregnancy, with the hypothesis that augmented vasoconstriction involves transient receptor potential canonical type-3 (TRPC3) and L- and T-type voltage-dependent Ca2+ channels. Immunohistochemistry showed TRPC3, L-type Cav1.2 (as the α1C subunit), T-type Cav3.1 (α1G), and Cav3.2 (α1H) localization to the uterine radial artery SM. Fluorescence intensity of TRPC3, Cav1.2, and Cav3.2 was increased, and Cav3.1 decreased in radial artery SM from pregnant rats. Western blot analysis confirmed increased TRPC3 protein expression in the radial artery from pregnant rats. Pressure myography incorporating pharmacological intervention to examine the role of these channels in uterine radial arteries showed an attenuation of phenylephrine (PE)-induced constriction with Pyr3 {1-[4-[(2,3,3-trichloro-1-oxo-2-propen-1-yl)amino]phenyl]-5-(trifluoromethyl)-1 H-pyrazole-4-carboxylic acid}-mediated TRPC3 inhibition or with nifedipine-mediated L-type channel block alone in vessels from pregnant rats; both effects of which were diminished in radial arteries from nonpregnant rats. Combined TRPC3 and L-type inhibition attenuated PE-induced constriction in radial arteries, and the residual vasoconstriction was reduced and abolished with T-type channel block with NNC 55-0396 in arteries from nonpregnant and pregnant rats, respectively. With SM Ca2+ stores depleted and in the presence of PE, nifedipine, and NNC 55-0396, blockade of TRPC3 reversed PE-induced constriction. These data suggest that TRPC3 channels act synergistically with L- and T-type channels to modulate radial artery vasoconstriction, with the mechanism being augmented in pregnancy.
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Affiliation(s)
- Sevvandi Senadheera
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Paul P. Bertrand
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - T. Hilton Grayson
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Leo Leader
- Leo Leader, School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Marianne Tare
- Department of Physiology, Monash University, Melbourne, Australia; and
| | - Timothy V. Murphy
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Shaun L. Sandow
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydoore, Australia
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Di Fiore DP, Beltrame JF. Chest pain in patients with 'normal angiography': could it be cardiac? INT J EVID-BASED HEA 2013; 11:56-68. [PMID: 23448331 DOI: 10.1111/1744-1609.12002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Approximately 20% of patients undergoing diagnostic angiography for the evaluation of chest pain are found to have a normal coronary angiogram. Although this finding is generally associated with a low risk of cardiac events, approximately half will continue to experience chest pain over the next 12 months. Therefore, the finding of normal angiography warrants further evaluation of the potential causes for the presenting chest pain if we are to improve the disability suffered by these patients. In this review, the potential non-cardiac and cardiac causes for the chest pain in patients with normal angiography are briefly discussed with an in-depth focus on coronary vasomotor disorders including coronary artery spasm (variant angina) and microvascular disorders such as syndrome X, microvascular angina, the coronary slow flow phenomenon and microvascular spasm.
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Affiliation(s)
- David P Di Fiore
- The Queen Elizabeth Hospital, Discipline of Medicine, The University of Adelaide, Woodville South, South Australia, Australia
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31
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Hansen PBL. Functional and pharmacological consequences of the distribution of voltage-gated calcium channels in the renal blood vessels. Acta Physiol (Oxf) 2013; 207:690-9. [PMID: 23351056 DOI: 10.1111/apha.12070] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 11/26/2012] [Accepted: 01/22/2013] [Indexed: 12/15/2022]
Abstract
Calcium channel blockers are widely used to treat hypertension because they inhibit voltage-gated calcium channels that mediate transmembrane calcium influx in, for example, vascular smooth muscle and cardiomyocytes. The calcium channel family consists of several subfamilies, of which the L-type is usually associated with vascular contractility. However, the L-, T- and P-/Q-types of calcium channels are present in the renal vasculature and are differentially involved in controlling vascular contractility, thereby contributing to regulation of kidney function and blood pressure. In the preglomerular vascular bed, all the three channel families are present. However, the T-type channel is the only channel in cortical efferent arterioles which is in contrast to the juxtamedullary efferent arteriole, and that leads to diverse functional effects of L- and T-type channel inhibition. Furthermore, by different mechanisms, T-type channels may contribute to both constriction and dilation of the arterioles. Finally, P-/Q-type channels are involved in the regulation of human intrarenal arterial contractility. The calcium blockers used in the clinic affect not only L-type but also P-/Q- and T-type channels. Therefore, the distinct effect obtained by inhibiting a given subtype or set of channels under experimental settings should be considered when choosing a calcium blocker for treatment. T-type channels seem to be crucial for regulating the GFR and the filtration fraction. Use of blockers is expected to lead to preferential efferent vasodilation, reduction of glomerular pressure and proteinuria. Therefore, renovascular T-type channels might provide novel therapeutic targets, and may have superior renoprotective effects compared to conventional calcium blockers.
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Affiliation(s)
- P. B. L. Hansen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense; Denmark
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32
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Björling K, Morita H, Olsen MF, Prodan A, Hansen PB, Lory P, Holstein-Rathlou NH, Jensen LJ. Myogenic tone is impaired at low arterial pressure in mice deficient in the low-voltage-activated CaV 3.1 T-type Ca(2+) channel. Acta Physiol (Oxf) 2013; 207:709-20. [PMID: 23356724 DOI: 10.1111/apha.12066] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/27/2012] [Accepted: 01/17/2013] [Indexed: 11/28/2022]
Abstract
AIM Using mice deficient in the CaV 3.1 T-type Ca(2+) channel, the aim of the present study was to elucidate the molecular identity of non-L-type channels involved in vascular tone regulation in mesenteric arteries and arterioles. METHODS We used immunofluorescence microscopy to localize CaV 3.1 channels, patch clamp electrophysiology to test the effects of a putative T-type channel blocker NNC 55-0396 on whole-cell Ca(2+) currents, pressure myography and Ca(2+) imaging to test diameter and Ca(2+) responses of the applied vasoconstrictors, and Q-PCR to check mRNA expression levels of several Ca(2+) handling proteins in wild-type and CaV 3.1(-/-) mice. RESULTS Our data indicated that CaV 3.1 channels are important for the maintenance of myogenic tone at low pressures (40-80 mm Hg), whereas they are not involved in high-voltage-activated Ca(2+) currents, Ca(2+) entry or vasoconstriction to high KCl in mesenteric arteries and arterioles. Furthermore, we show that NNC 55-0396 is not a specific T-type channel inhibitor, as it potently blocks L-type and non-L-type high-voltage-activated Ca(2+) currents in mouse mesenteric vascular smooth muscle cell. CONCLUSION Our data using mice deficient in the CaV 3.1 T-type channel represent new evidence for the involvement of non-L-type channels in arteriolar tone regulation. We showed that CaV 3.1 channels are important for the myogenic tone at low arterial pressure, which is potentially relevant under resting conditions in vivo. Moreover, CaV 3.1 channels are not involved in Ca(2+) entry and vasoconstriction to large depolarization with, for example, high KCl. Finally, we caution against using NNC 55-0396 as a specific T-type channel blocker in native cells expressing high-voltage-activated Ca(2+) channels.
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Affiliation(s)
- K. Björling
- Department of Veterinary Clinical and Animal Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
| | - H. Morita
- Special Patient Oral Care Unit; Kyushu University Hospital; Fukuoka; Japan
| | - M. F. Olsen
- Department of Veterinary Clinical and Animal Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
| | - A. Prodan
- Department of Veterinary Clinical and Animal Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
| | - P. B. Hansen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense; Denmark
| | - P. Lory
- CNRS; Institut de Génomique Fonctionnelle; Université de Montpellier; France
| | - N.-H. Holstein-Rathlou
- Department of Biomedical Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
| | - L. J. Jensen
- Department of Veterinary Clinical and Animal Sciences; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
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33
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Beltrame JF, Horowitz JD. Why Do Nitrates Have Limited Efficacy in Coronary Microvessels? Cardiovasc Drugs Ther 2013; 27:187-8. [DOI: 10.1007/s10557-013-6454-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Howitt L, Kuo IY, Ellis A, Chaston DJ, Shin HS, Hansen PB, Hill CE. Chronic deficit in nitric oxide elicits oxidative stress and augments T-type calcium-channel contribution to vascular tone of rodent arteries and arterioles. Cardiovasc Res 2013; 98:449-57. [DOI: 10.1093/cvr/cvt043] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Abd El-Rahman RR, Harraz OF, Brett SE, Anfinogenova Y, Mufti RE, Goldman D, Welsh DG. Identification of L- and T-type Ca2+ channels in rat cerebral arteries: role in myogenic tone development. Am J Physiol Heart Circ Physiol 2012; 304:H58-71. [PMID: 23103495 DOI: 10.1152/ajpheart.00476.2012] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
L-type Ca(2+) channels are broadly expressed in arterial smooth muscle cells, and their voltage-dependent properties are important in tone development. Recent studies have noted that these Ca(2+) channels are not singularly expressed in vascular tissue and that other subtypes are likely present. In this study, we ascertained which voltage-gated Ca(2+) channels are expressed in rat cerebral arterial smooth muscle and determined their contribution to the myogenic response. mRNA analysis revealed that the α(1)-subunit of L-type (Ca(v)1.2) and T-type (Ca(v)3.1 and Ca(v)3.2) Ca(2+) channels are present in isolated smooth muscle cells. Western blot analysis subsequently confirmed protein expression in whole arteries. With the use of patch clamp electrophysiology, nifedipine-sensitive and -insensitive Ba(2+) currents were isolated and each were shown to retain electrical characteristics consistent with L- and T-type Ca(2+) channels. The nifedipine-insensitive Ba(2+) current was blocked by mibefradil, kurtoxin, and efonidpine, T-type Ca(2+) channel inhibitors. Pressure myography revealed that L-type Ca(2+) channel inhibition reduced tone at 20 and 80 mmHg, with the greatest effect at high pressure when the vessel is depolarized. In comparison, the effect of T-type Ca(2+) channel blockade on myogenic tone was more limited, with their greatest effect at low pressure where vessels are hyperpolarized. Blood flow modeling revealed that the vasomotor responses induced by T-type Ca(2+) blockade could alter arterial flow by ∼20-50%. Overall, our findings indicate that L- and T-type Ca(2+) channels are expressed in cerebral arterial smooth muscle and can be electrically isolated from one another. Both conductances contribute to myogenic tone, although their overall contribution is unequal.
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Affiliation(s)
- Rasha R Abd El-Rahman
- Hotchkiss Brain and Libin Cardiovascular Research Institute and Department of Physiology and Pharmacology, University of Calgary, Alberta, Canada
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Inami T, Kataoka M, Shimura N, Ishiguro H, Kohshoh H, Taguchi H, Yanagisawa R, Hara Y, Satoh T, Yoshino H. Left ventricular dysfunction due to diffuse multiple vessel coronary artery spasm can be concealed in dilated cardiomyopathy. Eur J Heart Fail 2012; 14:1130-8. [PMID: 22713288 DOI: 10.1093/eurjhf/hfs103] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
AIMS Many patients with idiopathic dilated cardiomyopathy (DCM) have been diagnosed on the basis of the exclusion of significant coronary stenosis and the presence of left ventricular (LV) dysfunction. In the present study, we investigated the possibility that coronary multispasm is one of the mechanisms leading to diffuse idiopathic DCM-like LV dysfunction. METHODS AND RESULTS Forty-two patients with severely depressed LV function but without significant coronary stenosis were enrolled (baseline LV ejection fraction, 33 ± 11%). An acetylcholine (ACh) provocation test was performed at the time of coronary angiography. In patients with a positive ACh provocation test (n = 20), coronary angiography revealed multivessel diffuse coronary spasm with marked electrocardiogram changes. In patients with a negative ACh provocation test (n = 22), significant findings compatible with idiopathic DCM were more frequently observed on magnetic resonance imaging (MRI) or in LV biopsies compared with the ACh-positive group (MRI, 73% vs. 12%; and LV biopsy, 71% vs. 0%, respectively; P < 0.01). In the ACh-positive group, LV function significantly improved after the administration of calcium channel blockers (LV ejection fraction, 34 ± 12% vs. 54 ± 10%; and brain natriuretic peptide, 803 ± 482 pg/mL vs. 69 ± 84 pg/mL, at baseline and 1 year, respectively; P < 0.01). CONCLUSIONS Our results raise the possibility that patients with LV dysfunction due to repeated coronary multispasm are being diagnosed as idiopathic DCM, and that calcium channel blockers may prove to be a promising therapeutic strategy in those patients.
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Affiliation(s)
- Takumi Inami
- Division of Cardiology, Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan
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37
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Hansen PB, Poulsen CB, Walter S, Marcussen N, Cribbs LL, Skøtt O, Jensen BL. Functional Importance of L- and P/Q-Type Voltage-Gated Calcium Channels in Human Renal Vasculature. Hypertension 2011; 58:464-70. [DOI: 10.1161/hypertensionaha.111.170845] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Calcium channel blockers are widely used for treatment of hypertension, because they decrease peripheral vascular resistance through inhibition of voltage-gated calcium channels. Animal studies of renal vasculature have shown expression of several types of calcium channels that are involved in kidney function. It was hypothesized that human renal vascular excitation-contraction coupling involves different subtypes of channels. In human renal artery and dissected intrarenal blood vessels from nephrectomies, PCR analysis showed expression of L-type (Ca
v
1.2), P/Q-type (Ca
v
2.1), and T-type subtype (Ca
v
3.1 and Ca
v
3.2) voltage-gated calcium channels (Ca
v
s), and quantitative PCR showed highest expression of L-type channels in renal arteries and variable expression between patients of subtypes of calcium channels in intrarenal vessels. Immunohistochemical labeling of kidney sections revealed signals for Ca
v
2.1 and Ca
v
3.1 associated with smooth muscle cells of preglomerular and postglomerular vessels. In human intrarenal arteries, depolarization with potassium induced a contraction inhibited by the L-type antagonist nifedipine, EC
50
1.2×10
−8
mol/L. The T-type antagonist mibefradil inhibited the potassium-induced constriction with large variations between patients. Interestingly, the P/Q-type antagonist, ω-agatoxin IVA, inhibited significantly the contraction with 24% at 10
−9
mol/L. In conclusion L-, P/Q, and T-type channels are expressed in human renal blood vessels, and L- and P/Q-type channels are of functional importance for the depolarization-induced vasoconstriction. The contribution of P/Q-type channels to contraction in the human vasculature is a novel mechanism for the regulation of renal blood flow and suggests that clinical treatment with calcium blockers might affect vascular reactivity also through P/Q-type channel inhibition.
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Affiliation(s)
- Pernille B. Hansen
- From the Cardiovascular and Renal Research (P.B.H., C.B.P., O.S., B.L.J.) and Department of Pathology (N.M.), University of Southern Denmark, Odense, Denmark; Department of Urology (S.W.), Odense University Hospital, Odense, Denmark; Cardiovascular Institute (L.L.C.), Loyola University Medical Center, Maywood, IL
| | - Christian B. Poulsen
- From the Cardiovascular and Renal Research (P.B.H., C.B.P., O.S., B.L.J.) and Department of Pathology (N.M.), University of Southern Denmark, Odense, Denmark; Department of Urology (S.W.), Odense University Hospital, Odense, Denmark; Cardiovascular Institute (L.L.C.), Loyola University Medical Center, Maywood, IL
| | - Steen Walter
- From the Cardiovascular and Renal Research (P.B.H., C.B.P., O.S., B.L.J.) and Department of Pathology (N.M.), University of Southern Denmark, Odense, Denmark; Department of Urology (S.W.), Odense University Hospital, Odense, Denmark; Cardiovascular Institute (L.L.C.), Loyola University Medical Center, Maywood, IL
| | - Niels Marcussen
- From the Cardiovascular and Renal Research (P.B.H., C.B.P., O.S., B.L.J.) and Department of Pathology (N.M.), University of Southern Denmark, Odense, Denmark; Department of Urology (S.W.), Odense University Hospital, Odense, Denmark; Cardiovascular Institute (L.L.C.), Loyola University Medical Center, Maywood, IL
| | - Leanne L. Cribbs
- From the Cardiovascular and Renal Research (P.B.H., C.B.P., O.S., B.L.J.) and Department of Pathology (N.M.), University of Southern Denmark, Odense, Denmark; Department of Urology (S.W.), Odense University Hospital, Odense, Denmark; Cardiovascular Institute (L.L.C.), Loyola University Medical Center, Maywood, IL
| | - Ole Skøtt
- From the Cardiovascular and Renal Research (P.B.H., C.B.P., O.S., B.L.J.) and Department of Pathology (N.M.), University of Southern Denmark, Odense, Denmark; Department of Urology (S.W.), Odense University Hospital, Odense, Denmark; Cardiovascular Institute (L.L.C.), Loyola University Medical Center, Maywood, IL
| | - Boye L. Jensen
- From the Cardiovascular and Renal Research (P.B.H., C.B.P., O.S., B.L.J.) and Department of Pathology (N.M.), University of Southern Denmark, Odense, Denmark; Department of Urology (S.W.), Odense University Hospital, Odense, Denmark; Cardiovascular Institute (L.L.C.), Loyola University Medical Center, Maywood, IL
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Gender Differences in Patients with Stable Angina attending Primary Care Practices. Heart Lung Circ 2011; 20:452-9. [DOI: 10.1016/j.hlc.2011.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 02/09/2011] [Accepted: 02/21/2011] [Indexed: 11/18/2022]
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Kuo IYT, Wölfle SE, Hill CE. T-type calcium channels and vascular function: the new kid on the block? J Physiol 2010; 589:783-95. [PMID: 21173074 DOI: 10.1113/jphysiol.2010.199497] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
While L-type voltage-dependent calcium channels have long been considered the predominant source of calcium for myogenic constriction, recent studies of both cerebral and systemic circulations have provided evidence for the prominent expression of other members of the voltage-dependent calcium channel family, in particular the low voltage activated T-type channels. Although physiological studies have not supported the involvement of a classical low voltage activated, T-type channel in vascular function, evidence is accumulating that points to the involvement of a non-L-type, high voltage activated channel with sensitivity to T-type channel antagonists. We propose that this may arise due to expression of a T-type channel splice variant with unique biophysical characteristics resulting in a more depolarised profile. Expression of these channels in smooth muscle cells would broaden the voltage range over which sustained calcium influx occurs, while expression of T-type channels in endothelial cells could provide a feedback mechanism to prevent excessive vasoconstriction. Perturbation of this balance during pathophysiological conditions by upregulation of channel expression and endothelial dysfunction could contribute to vasospastic conditions and therapy-refractory hypertension.
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Affiliation(s)
- Ivana Y-T Kuo
- Department of Neuroscience, John Curtin School of Medical Research, GPO Box 334, Canberra, ACT, Australia 0200
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40
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Markandeya YS, Fahey JM, Pluteanu F, Cribbs LL, Balijepalli RC. Caveolin-3 regulates protein kinase A modulation of the Ca(V)3.2 (alpha1H) T-type Ca2+ channels. J Biol Chem 2010; 286:2433-44. [PMID: 21084288 DOI: 10.1074/jbc.m110.182550] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Voltage-gated T-type Ca(2+) channel Ca(v)3.2 (α(1H)) subunit, responsible for T-type Ca(2+) current, is expressed in different tissues and participates in Ca(2+) entry, hormonal secretion, pacemaker activity, and arrhythmia. The precise subcellular localization and regulation of Ca(v)3.2 channels in native cells is unknown. Caveolae containing scaffolding protein caveolin-3 (Cav-3) localize many ion channels, signaling proteins and provide temporal and spatial regulation of intracellular Ca(2+) in different cells. We examined the localization and regulation of the Ca(v)3.2 channels in cardiomyocytes. Immunogold labeling and electron microscopy analysis demonstrated co-localization of the Ca(v)3.2 channel and Cav-3 relative to caveolae in ventricular myocytes. Co-immunoprecipitation from neonatal ventricular myocytes or transiently transfected HEK293 cells demonstrated that Ca(v)3.1 and Ca(v)3.2 channels co-immunoprecipitate with Cav-3. GST pulldown analysis confirmed that the N terminus region of Cav-3 closely interacts with Ca(v)3.2 channels. Whole cell patch clamp analysis demonstrated that co-expression of Cav-3 significantly decreased the peak Ca(v)3.2 current density in HEK293 cells, whereas co-expression of Cav-3 did not alter peak Ca(v)3.1 current density. In neonatal mouse ventricular myocytes, overexpression of Cav-3 inhibited the peak T-type calcium current (I(Ca,T)) and adenovirus (AdCa(v)3.2)-mediated increase in peak Ca(v)3.2 current, but did not affect the L-type current. The protein kinase A-dependent stimulation of I(Ca,T) by 8-Br-cAMP (membrane permeable cAMP analog) was abolished by siRNA directed against Cav-3. Our findings on functional modulation of the Ca(v)3.2 channels by Cav-3 is important for understanding the compartmentalized regulation of Ca(2+) signaling during normal and pathological processes.
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Affiliation(s)
- Yogananda S Markandeya
- Department of Medicine, Cellular and Molecular Arrhythmia Research Program, University of Wisconsin, Madison, Wisconsin 53706, USA
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41
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Actions of thalidomide in producing vascular relaxations. Eur J Pharmacol 2010; 644:113-9. [DOI: 10.1016/j.ejphar.2010.06.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 05/26/2010] [Accepted: 06/21/2010] [Indexed: 11/20/2022]
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42
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Zhang Z, Lin H, Cao C, Khurana S, Pallone TL. Voltage-gated divalent currents in descending vasa recta pericytes. Am J Physiol Renal Physiol 2010; 299:F862-71. [PMID: 20630935 DOI: 10.1152/ajprenal.00321.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Multiple voltage-gated Ca(2+) channel (Ca(V)) subtypes have been reported to participate in control of the juxtamedullary glomerular arterioles of the kidney. Using the patch-clamp technique, we examined whole cell Ca(V) currents of pericytes that contract descending vasa recta (DVR). The dihydropyridine Ca(V) agonist FPL64176 (FPL) stimulated inward Ca(2+) and Ba(2+) currents that activated with threshold depolarizations to -40 mV and maximized between -20 and -10 mV. These currents were blocked by nifedipine (1 μM) and Ni(2+) (100 and 1,000 μM), exhibited slow inactivation, and conducted Ba(2+) > Ca(2+) at a ratio of 2.3:1, consistent with "long-lasting" L-type Ca(V). In FPL, with 1 mM Ca(2+) as charge carrier, Boltzmann fits yielded half-maximal activation potential (V(1/2)) and slope factors of -57.9 mV and 11.0 for inactivation and -33.3 mV and 4.4 for activation. In the absence of FPL stimulation, higher concentrations of divalent charge carriers were needed to measure basal currents. In 10 mM Ba(2+), pericyte Ca(V) currents activated with threshold depolarizations to -30 mV, were blocked by nifedipine, exhibited voltage-dependent block by diltiazem (10 μM), and conducted Ba(2+) > Ca(2+) at a ratio of ∼2:1. In Ca(2+), Boltzmann fits to the data yielded V(1/2) and slope factors of -39.6 mV and 10.0 for inactivation and 2.8 mV and 7.7 for activation. In Ba(2+), V(1/2) and slope factors were -29.2 mV and 9.2 for inactivation and -5.6 mV and 6.1 for activation. Neither calciseptine (10 nM), mibefradil (1 μM), nor ω-agatoxin IVA (20 and 100 nM) blocked basal Ba(2+) currents. Calciseptine (10 nM) and mibefradil (1 μM) also failed to reverse ANG II-induced DVR vasoconstriction, although raising mibefradil concentration to 10 μM was partially effective. We conclude that DVR pericytes predominantly express voltage-gated divalent currents that are carried by L-type channels.
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Affiliation(s)
- Zhong Zhang
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Kuo IY, Ellis A, Seymour VAL, Sandow SL, Hill CE. Dihydropyridine-insensitive calcium currents contribute to function of small cerebral arteries. J Cereb Blood Flow Metab 2010; 30:1226-39. [PMID: 20125181 PMCID: PMC2949209 DOI: 10.1038/jcbfm.2010.11] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although dihydropyridines are widely used for the treatment of vasospasm, their effectiveness is questionable, suggesting that other voltage-dependent calcium channels (VDCCs) contribute to control of cerebrovascular tone. This study therefore investigated the role of dihydropyridine-insensitive VDCCs in cerebrovascular function. Using quantitative PCR and immunohistochemistry, we found mRNA and protein for L-type (Ca(V)1.2) and T-type (Ca(V)3.1 and Ca(V)3.2) channels in adult rat basilar and middle cerebral arteries and their branches. Immunoelectron microscopy revealed both L- and T-type channels in smooth muscle cell (SMC) membranes. Using patch clamp electrophysiology, we found that a high-voltage-activated calcium current, showing T-type channel kinetics and insensitivity to nifedipine and nimodipine, comprised approximately 20% of current in SMCs of the main arteries and approximately 45% of current in SMCs from branches. Both components were abolished by the T-type antagonists mibefradil, NNC 55-0396, and efonidipine. Although nifedipine completely blocked vasoconstriction in pressurized basilar arteries, a nifedipine-insensitive constriction was found in branches and this increased in magnitude as vessel size decreased. We conclude that a heterogeneous population of VDCCs contributes to cerebrovascular function, with dihydropyridine-insensitive channels having a larger role in smaller vessels. Sensitivity of these currents to nonselective T-type channel antagonists suggests that these drugs may provide a more effective treatment for therapy-refractory cerebrovascular constriction.
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Affiliation(s)
- Ivana Y Kuo
- John Curtin School of Medical Research, ANU College of Medicine, Biology and Environment, The Australian National University, Canberra, Australian Capital Territory, Australia
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Godfraind T. Is Combined L- and T-Channel Blockade Better Than L-Channel Blockade in Therapy? Hypertension 2009; 54:e3; author reply e4. [DOI: 10.1161/hypertensionaha.109.133504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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