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Song R, Yadav P, Dangudubiyyam SV, Hofmann A, Mishra JS, Kumar S. Gestational intermittent hypoxia induces endothelial dysfunction and hypertension in pregnant rats: role of endothelin type B receptor†. Biol Reprod 2024; 110:185-197. [PMID: 37823770 DOI: 10.1093/biolre/ioad139] [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: 07/06/2023] [Revised: 08/29/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023] Open
Abstract
Obstructive sleep apnea is a recognized risk factor for gestational hypertension, yet the exact mechanism behind this association remains unclear. Here, we tested the hypothesis that intermittent hypoxia, a hallmark of obstructive sleep apnea, induces gestational hypertension through perturbed endothelin-1 signaling. Pregnant Sprague-Dawley rats were subjected to normoxia (control), mild intermittent hypoxia (10.5% O2), or severe intermittent hypoxia (6.5% O2) from gestational days 10-21. Blood pressure was monitored. Plasma was collected and mesenteric arteries were isolated for myograph and protein analyses. The mild and severe intermittent hypoxia groups demonstrated elevated blood pressure, reduced plasma nitrate/nitrite, and unchanged endothelin-1 levels compared to the control group. Western blot analysis revealed decreased expression of endothelin type B receptor and phosphorylated endothelial nitric oxide synthase, while the levels of endothelin type A receptor and total endothelial nitric oxide synthase remained unchanged following intermittent hypoxia exposure. The contractile responses to potassium chloride, phenylephrine, and endothelin-1 were unaffected in endothelium-denuded arteries from mild and severe intermittent hypoxia rats. However, mild and severe intermittent hypoxia rats exhibited impaired endothelium-dependent vasorelaxation responses to endothelin type B receptor agonist IRL-1620 and acetylcholine compared to controls. Endothelium denudation abolished IRL-1620-induced vasorelaxation, supporting the involvement of endothelium in endothelin type B receptor-mediated relaxation. Treatment with IRL-1620 during intermittent hypoxia exposure significantly attenuated intermittent hypoxia-induced hypertension in pregnant rats. This was associated with elevated circulating nitrate/nitrite levels, enhanced endothelin type B receptor expression, increased endothelial nitric oxide synthase activation, and improved vasodilation responses. Our data suggested that intermittent hypoxia exposure during gestation increases blood pressure in pregnant rats by suppressing endothelin type B receptor-mediated signaling, providing a molecular mechanism linking intermittent hypoxia and gestational hypertension.
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Affiliation(s)
- Ruolin Song
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Pankaj Yadav
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sri Vidya Dangudubiyyam
- Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alissa Hofmann
- Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jay S Mishra
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sathish Kumar
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Jia M, Su X, Qin Q, Li Y, Wang S, Chen Y. Tetrahydroxystilbene glucoside attenuated homocysteine-upregulated endothelin receptors in vascular smooth muscle cells via the ERK 1 /2 /NF-κB signaling pathway. Phytother Res 2022; 36:3352-3361. [PMID: 35648450 DOI: 10.1002/ptr.7519] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 05/02/2022] [Accepted: 05/18/2022] [Indexed: 11/12/2022]
Abstract
2,3,5,4'-Tetrahydrostilbene-2-o-β-d-glucoside (TSG) is the main active component of Polygonum multiflorum Thunb. It has effects on hypertension. However, the mechanism is unclear. Current research is devoted to exploring the mechanism of TSG improving HHcy-induced hypertension. The mice received a subcutaneous injection of Hcy in the presence or absence of TSG for 4 weeks. Blood pressure (BP) was measured using a noninvasive tail-cuff plethysmography method. Levels of plasma Hcy and endothelin-1 were measured using ELISA. Rat SMA without endothelium was cultured in a serum-free medium in the presence or absence of TSG with or without Hcy. The contractile response to sarafotoxin 6c or endothein-1 was studied using a sensitive myography. The levels of protein were detected using Western blotting. The results showed that TSG lowered HHcy-elevated BP and decreased levels of plasma Hcy and endothelin-1 in mice. Furthermore, the results showed that TSG inhibited Hcy-upregulated ET receptor expression and ET receptor-mediated contractile responses as well as the levels of p-ERK1/2 and p-p65 in SMA. In vivo results further validate the in vitro results. In conclusion, TSG can decrease the levels of plasma Hcy and ET-1 and downregulate Hcy-upregulated ET receptors in VSMCs by inhibiting the ERK1/2 /NF-κB/ETB2 pathway to lower the BP.
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Affiliation(s)
- Min Jia
- Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Xingli Su
- School of Basic and Medical Sciences, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Qiaohong Qin
- Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Yajuan Li
- Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Siwang Wang
- Shaanxi Key Laboratory of Biomedicine, School of Life Sciences, Northwest University, Xi'an, Shaanxi, China.,Institute of Materia Medic, Department of Natural Medicine School of Pharmacy, Air Force Medical University, Xi'an, Shaanxi, China
| | - Yulong Chen
- Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, Shaanxi, China
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Sun X, Zhang H, Qin Q, Zhang X, Hou Y, Chen D, Su X, Jia M, Chen Y. Inhibitors of the MAPK/ NF-κB pathway attenuate the upregulation of the ET B receptor mediated by high glucose in vascular smooth muscle cells. Peptides 2022; 150:170732. [PMID: 34971676 DOI: 10.1016/j.peptides.2021.170732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 12/26/2021] [Accepted: 12/27/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND Increased vascular smooth muscle cell (VSMC) endothelin type B (ETB) receptor expression is involved in cardiovascular diseases. High glucose (HG) in diabetes is closely related to cardiovascular complications. Although diabetes upregulates VSMC endothelin subtype B (ETB) receptors, its mechanism is still unclear. Our aim is to investigate the mechanism of HG-induced ETB receptors in VSMCs. METHODS Rat superior mesenteric arteries (SMAs) without endothelium were cultured in medium without serum for 24 h. HG with or without mitogen-activated protein kinase (MAPK) signaling pathway inhibitors and downstream nuclear factor-kappaB (NF-κB) inhibitors was coincubated with SMAs. A sensitive myograph detected the contractile responses to sarafotoxin 6c. Western blotting and immunofluorescence staining were used to determine protein expression. RESULTS HG promoted the expression of VSMC ETB receptors in rat SMAs and enhanced the ETB receptor-induced contractile response. The results showed that HG increased vascular smooth muscle cell (VSMC) ETB receptor expression and ETB receptor-induced contractile responses in rat SMAs. Both extracellular signal-related kinase 1 and 2 (ERK1/2) inhibitors (U0126) and P38 inhibitors (SB203580) significantly inhibited HG-increased VSMC ETB receptors. However, a C-jun terminal kinase (p-JNK) inhibitor (SP600125) did not affect HG- upregulated VSMC ETB receptors. Further study showed that NF-κB using an IκB kinase inhibitor (wedelolactone) also significantly inhibited HG-increased VSMC ETB receptors. CONCLUSION In conclusion, HG upregulated the VSMC ETB receptor by activating the ERK1/2- or P38- NF-κB signaling pathway.
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Affiliation(s)
- Xia Sun
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China; School of Basic and Medical Sciences, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Hongmei Zhang
- The First Affiliated Hospital of Xi'an Medical University, Xi'an Medical University, Xi'an, Shaanxi, 710077, China
| | - Qiaohong Qin
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Xin Zhang
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Ying Hou
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Di Chen
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China; School of Basic and Medical Sciences, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Xingli Su
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China; School of Basic and Medical Sciences, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Min Jia
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China.
| | - Yulong Chen
- Institute of Basic and Translational Medicine, Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi, 710021, China.
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Miller E, Czopek A, Duthie KM, Kirkby NS, van de Putte EEF, Christen S, Kimmitt RA, Moorhouse R, Castellan RFP, Kotelevtsev YV, Kuc RE, Davenport AP, Dhaun N, Webb DJ, Hadoke PWF. Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling. Hypertension 2016; 69:275-285. [PMID: 28028193 PMCID: PMC5222555 DOI: 10.1161/hypertensionaha.115.07031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 01/02/2016] [Accepted: 11/30/2016] [Indexed: 01/06/2023]
Abstract
Supplemental Digital Content is available in the text. The role of smooth muscle endothelinB (ETB) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ETB receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ETB receptors were selectively deleted from smooth muscle by crossing floxed ETB mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ETB deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ETB was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ETB-mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ETB-mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ETB knockout compared with controls (+4.2±0.2 mm Hg; P<0.0001), but salt-induced and ETB blockade–mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ETB-mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ETB knockout mice. In the absence of other pathology, ETB receptors in vascular smooth muscle make a small but significant contribution to ETB-dependent regulation of BP. These ETB receptors have no effect on vascular contraction or neointimal remodeling.
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Affiliation(s)
- Eileen Miller
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Alicja Czopek
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Karolina M Duthie
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Nicholas S Kirkby
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Elisabeth E Fransen van de Putte
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Sibylle Christen
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Robert A Kimmitt
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Rebecca Moorhouse
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Raphael F P Castellan
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Yuri V Kotelevtsev
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Rhoda E Kuc
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Anthony P Davenport
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Neeraj Dhaun
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - David J Webb
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.)
| | - Patrick W F Hadoke
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, United Kingdom (E.M., A.C., K.M.D., N.S.K., E.E.F.v.d.P., R.A.K., R.M., R.F.P.C., N.D., D.J.W., P.W.F.H.); University of Basel, Switzerland (S.C.); Centre for Functional Genomics, Skolkovo Institute of Science and Technology, Russian Federation (Y.V.K.); and Division of Experimental Medicine and Immunotherapeutics, Addenbrooke's Hospital, Cambridge, United Kingdom (R.E.K., A.P.D.).
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Homocysteine regulates endothelin type B receptors in vascular smooth muscle cells. Vascul Pharmacol 2016; 87:100-109. [DOI: 10.1016/j.vph.2016.08.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/13/2016] [Accepted: 08/27/2016] [Indexed: 12/31/2022]
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The sirt1/NF-kB signaling pathway is involved in regulation of endothelin type B receptors mediated by homocysteine in vascular smooth muscle cells. Biomed Pharmacother 2016; 84:1979-1985. [DOI: 10.1016/j.biopha.2016.11.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 10/28/2016] [Accepted: 11/02/2016] [Indexed: 12/27/2022] Open
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Tilbury CR, Verster J. A fatal bite from the burrowing asp Atractaspis corpulenta (Hallowell 1854). Toxicon 2016; 118:21-6. [DOI: 10.1016/j.toxicon.2016.04.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/27/2016] [Accepted: 04/14/2016] [Indexed: 10/21/2022]
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Endothelin receptors, renal effects and blood pressure. Curr Opin Pharmacol 2015; 21:25-34. [DOI: 10.1016/j.coph.2014.12.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 11/23/2022]
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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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Meyers KEC, Sethna C. Endothelin antagonists in hypertension and kidney disease. Pediatr Nephrol 2013; 28:711-20. [PMID: 23070275 DOI: 10.1007/s00467-012-2316-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 01/11/2023]
Abstract
The endothelin (ET) system seems to play a pivotal role in hypertension and in proteinuric kidney disease, including the micro- and macro-vascular complications of diabetes. Endothelin-1 (ET-1) is a multifunctional peptide that primarily acts as a potent vasoconstrictor with direct effects on systemic vasculature and the kidney. ET-1 and ET receptors are expressed in the vascular smooth muscle cells, endothelial cells, fibroblasts and macrophages in systemic vasculature and arterioles of the kidney, and are associated with collagen accumulation, inflammation, extracellular matrix remodeling, and renal fibrosis. Experimental evidence and recent clinical studies suggest that endothelin receptor blockade, in particular selective ETAR blockade, holds promise in the treatment of hypertension, proteinuria, and diabetes. Concomitant blockade of the ETB receptor is not usually beneficial and may lead to vasoconstriction and salt and water retention. The side-effect profile of ET receptor antagonists and relatively poor antagonist selectivity for ETA receptor are limitations that need to be addressed. This review will discuss what is currently known about the endothelin system, the role of ET-1 in the pathogenesis of hypertension and kidney disease, and summarize literature on the therapeutic potential of endothelin system antagonism.
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Affiliation(s)
- Kevin E C Meyers
- Nephrology Division, Department of Pediatrics, The Children's Hospital of Philadelphia, 34th and Civic Center Boulevard, Philadelphia, PA 19104, USA.
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Wang Y, Zhang H, Wang Z, Geng Z, Liu H, Yang H, Song P, Liu Q. Therapeutic effect of nerve growth factor on cerebral infarction in dogs using the hemisphere anomalous volume ratio of diffusion-weighted magnetic resonance imaging. Neural Regen Res 2012; 7:1873-80. [PMID: 25624813 PMCID: PMC4298901 DOI: 10.3969/j.issn.1673-5374.2012.24.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/19/2012] [Indexed: 11/18/2022] Open
Abstract
A model of focal cerebral ischemic infarction was established in dogs through middle cerebral artery occlusion of the right side. Thirty minutes after occlusion, models were injected with nerve growth factor adjacent to the infarct locus. The therapeutic effect of nerve growth factor against cerebral infarction was assessed using the hemisphere anomalous volume ratio, a quantitative index of diffusion-weighted MRI. At 6 hours, 24 hours, 7 days and 3 months after modeling, the hemisphere anomalous volume ratio was significantly reduced after treatment with nerve growth factor. Hematoxylin-eosin staining, immunohistochemistry, electron microscopy and neurological function scores showed that infarct defects were slightly reduced and neurological function significantly improved after nerve growth factor treatment. This result was consistent with diffusion-weighted MRI measurements. Experimental findings indicate that nerve growth factor can protect against cerebral infarction, and that the hemisphere anomalous volume ratio of diffusion-weighted MRI can be used to evaluate the therapeutic effect.
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Affiliation(s)
- Yong Wang
- Department of Radiology, the Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
| | - Hui Zhang
- Department of Radiology, Hebei General Hospital, Shijiazhuang 050051, Hebei Province, China
| | - Zhe Wang
- Department of Computer Science, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050031, Hebei Province, China
| | - Zuojun Geng
- Department of Radiology, the Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
| | - Huaijun Liu
- Department of Radiology, the Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
| | - Haiqing Yang
- Department of Radiology, the Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
| | - Peng Song
- Department of Radiology, the Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
| | - Qing Liu
- Department of Radiology, the Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
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Activation of nuclear factor-κB pathway is responsible for tumor necrosis factor-α-induced up-regulation of endothelin B2 receptor expression in vascular smooth muscle cells in vitro. Toxicol Lett 2012; 209:107-12. [DOI: 10.1016/j.toxlet.2011.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Accepted: 12/12/2011] [Indexed: 11/20/2022]
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13
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Bosentan, a selective and more potent antagonist for Atractaspis envenomation than the specific antivenom. Toxicon 2011; 57:861-70. [PMID: 21392521 DOI: 10.1016/j.toxicon.2011.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 02/25/2011] [Accepted: 03/01/2011] [Indexed: 11/23/2022]
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14
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Kohan DE, Rossi NF, Inscho EW, Pollock DM. Regulation of blood pressure and salt homeostasis by endothelin. Physiol Rev 2011; 91:1-77. [PMID: 21248162 DOI: 10.1152/physrev.00060.2009] [Citation(s) in RCA: 276] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Endothelin (ET) peptides and their receptors are intimately involved in the physiological control of systemic blood pressure and body Na homeostasis, exerting these effects through alterations in a host of circulating and local factors. Hormonal systems affected by ET include natriuretic peptides, aldosterone, catecholamines, and angiotensin. ET also directly regulates cardiac output, central and peripheral nervous system activity, renal Na and water excretion, systemic vascular resistance, and venous capacitance. ET regulation of these systems is often complex, sometimes involving opposing actions depending on which receptor isoform is activated, which cells are affected, and what other prevailing factors exist. A detailed understanding of this system is important; disordered regulation of the ET system is strongly associated with hypertension and dysregulated extracellular fluid volume homeostasis. In addition, ET receptor antagonists are being increasingly used for the treatment of a variety of diseases; while demonstrating benefit, these agents also have adverse effects on fluid retention that may substantially limit their clinical utility. This review provides a detailed analysis of how the ET system is involved in the control of blood pressure and Na homeostasis, focusing primarily on physiological regulation with some discussion of the role of the ET system in hypertension.
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Affiliation(s)
- Donald E Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
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15
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Enouri S, Monteith G, Johnson R. Characteristics of myogenic reactivity in isolated rat mesenteric veins. Am J Physiol Regul Integr Comp Physiol 2011; 300:R470-8. [DOI: 10.1152/ajpregu.00491.2010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mechanisms of mechanically induced venous tone and its interaction with the endothelium and key vasoactive neurohormones are not well established. We investigated the contribution of the endothelium, l-type voltage-operated calcium channels (l-VOCCs), and PKC and Rho kinase to myogenic reactivity in mesenteric vessels exposed to increasing transmural pressure. The interaction of myogenic reactivity with norepinephrine (NE) and endothelin-1 (ET-1) was also investigated. Pressure myography was used to study isolated, cannulated, third-order rat mesenteric small veins and arteries. NE and ET-1 concentration response curves were constructed at low, intermediate, and high transmural pressures. Myogenic reactivity was not altered by nitric oxide synthase inhibition with Nω-nitro-l-arginine (l-NNA; 100 μM) or endothelium removal in both vessels. l-VOCCs blockade (nifedipine, 1 μM) completely abolished arterial tone, while only partially reducing venous tone. PKC (chelerythrine, 2.5 μM) and Rho kinase (Y27632, 3 μM) inhibitors largely abolished venous and arterial myogenic reactivity. There was no significant difference in the sensitivity of NE or ET-1-induced contractions within vessels. However, veins were more sensitive to NE and ET-1 when compared with corresponding arteries at low, intermediate, and high transmural pressures, respectively. These results suggest that 1) myogenic factors are important contributors to net venous tone in mesenteric veins; 2) PKC and Rho activation are important in myogenic reactivity in both vessels, while l-VOCCs play a limited role in the veins vs. the arteries, and the endothelium does not appear to modulate myogenic reactivity in either vessel type; and 3) mesenteric veins maintain an enhanced sensitivity to NE and ET-1 compared with the arteries when studied under conditions of changing transmural distending pressure.
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Affiliation(s)
| | - Gabrielle Monteith
- Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
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Kisanuki YY, Emoto N, Ohuchi T, Widyantoro B, Yagi K, Nakayama K, Kedzierski RM, Hammer RE, Yanagisawa H, Williams SC, Richardson JA, Suzuki T, Yanagisawa M. Low Blood Pressure in Endothelial Cell–Specific Endothelin 1 Knockout Mice. Hypertension 2010; 56:121-8. [DOI: 10.1161/hypertensionaha.109.138701] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Yaz Y. Kisanuki
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Noriaki Emoto
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Takashi Ohuchi
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Bambang Widyantoro
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Keiko Yagi
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Kazuhiko Nakayama
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Rafal M. Kedzierski
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Robert E. Hammer
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Hiromi Yanagisawa
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - S. Clay Williams
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - James A. Richardson
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Takashi Suzuki
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
| | - Masashi Yanagisawa
- From the Howard Hughes Medical Institute (Y.Y.K., T.O., R.M.K., S.C.W., M.Y.), Departments of Molecular Genetics (Y.Y.K., T.O., R.M.K., M.Y.), Biochemistry (R.E.H.), Molecular Biology (H.Y., J.A.R.), Pathology (J.A.R.), and Radiology (R.M.K.), and Donald W. Reynolds Cardiovascular Clinical Research Center (M.Y.), University of Texas Southwestern Medical Center, Dallas, Tex; Department of Neurology (Y.Y.K.), Ohio State University, Columbus, Ohio; Department of Pathology (T.S.), Tohoku University
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Tykocki NR, Gariepy CE, Watts SW. Endothelin ET(B) receptors in arteries and veins: multiple actions in the vein. J Pharmacol Exp Ther 2009; 329:875-81. [PMID: 19297422 DOI: 10.1124/jpet.108.145953] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endothelin receptors (ET(A) and ET(B)) mediate responses to ET-1. ET(B) receptor function seems to differ between a similarly sized arterial and venous pair, the rat vena cava (RVC) and rat thoracic aorta (RA). ET(B) receptors mediate RVC contraction directly, but it is unclear whether ET(B) receptors mediate contraction in RA. Because of these apparent differences in ET(B) receptor-mediated vascular contraction, we hypothesize that relaxant ET(B)-receptor mechanisms in RVC would be different from those in RA. RA and RVC rings were isolated from rats for measurement of isometric contraction. When contracted with prostaglandin F-2alpha (PGF-2alpha) (20 microM), the ET(B) receptor agonist sarafotoxin-6c (S6c) (100 nM) significantly relaxed RA and RVC. N(omega)-Nitro-L-arginine (LNNA) (100 microM) or endothelial denudation abolished relaxation to S6c in RA. By contrast, S6c-induced relaxation of RVC was attenuated but not abolished by LNNA and endothelial denudation. RVC (PGF-2alpha-contracted) relaxed to low concentrations of ET-1, whereas under the same conditions RA responded with contraction. ET-1-induced relaxation in RA was observed only with ET(A) receptor blockade. Vessels from dopamine-beta-hydroxylase-ET(B) transgenic rats, which lack functional ET(B) receptors in the vasculature, were also used. RVC (PGF-2alpha-contracted) from these rats did not relax to ET-1. Thus, although both RA and RVC possess endothelial relaxant ET(B) receptors, RA and RVC differ in that relaxant ET(B) receptors may also be present in smooth muscle of RVC. Moreover, the mechanisms of endothelial cell ET(B) receptor-mediated relaxation in RA and RVC are not the same.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, B445 Life Sciences Bldg., East Lansing, MI 48824, USA.
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18
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Li M, Dai X, Watts S, Kreulen D, Fink G. Increased superoxide levels in ganglia and sympathoexcitation are involved in sarafotoxin 6c-induced hypertension. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1546-54. [PMID: 18768769 DOI: 10.1152/ajpregu.00783.2007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Endothelin (ET) type B receptors (ET(B)R) are expressed in multiple tissues and perform different functions depending on their location. ET(B)R mediate endothelium-dependent vasodilation, clearance of circulating ET, and diuretic effects; all of these should produce a fall in arterial blood pressure. However, we recently showed that chronic activation of ET(B)R in rats with the selective agonist sarafotoxin 6c (S6c) causes sustained hypertension. We have proposed that one mechanism of this effect is constriction of capacitance vessels. The current study was performed to determine whether S6c hypertension is caused by increased generation of reactive oxygen species (ROS) and/or activation of the sympathetic nervous system. The model used was continuous 5-day infusion of S6c into male Sprague-Dawley rats. No changes in superoxide anion levels in arteries and veins were found in hypertensive S6c-treated rats. However, superoxide levels were increased in sympathetic ganglia from S6c-treated rats. In addition, superoxide levels in ganglia increased progressively the longer the animals received S6c. Treatment with the antioxidant tempol impaired S6c-induced hypertension and decreased superoxide levels in ganglia. Acute ganglion blockade lowered blood pressure more in S6c-treated rats than in vehicle-treated rats. Although plasma norepinephrine levels were not increased in S6c hypertension, surgical ablation of the celiac ganglion plexus, which provides most of the sympathetic innervation to the splanchnic organs, significantly attenuated hypertension development. The results suggest that S6c-induced hypertension is partially mediated by sympathoexcitation to the splanchnic organs driven by increased oxidative stress in prevertebral sympathetic ganglia.
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Affiliation(s)
- Melissa Li
- Dept. of Pharmacology and Toxicology, B440 Life Sciences, Michigan State Univ., East Lansing, MI 48824, USA
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Effect of ovariectomy on blood pressure and venous tone in female spontaneously hypertensive rats. Am J Hypertens 2008; 21:983-8. [PMID: 18636067 DOI: 10.1038/ajh.2008.237] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Venous capacitance plays an important role in circulatory homeostasis. A number of reports have suggested an effect of estrogen on venous function. This study tested the hypothesis that ovariectomy would increase venous tone in the female spontaneously hypertensive rat (SHR) via autonomic mechanisms. METHODS Five-week-old female SHR were subjected to sham operation (Sham) or ovariectomy (OVX). At 10 weeks of age, the rats were instrumented for the measurement of arterial and venous pressure. A balloon catheter was advanced into the right atrium. Mean circulatory filling pressure (MCFP), an index of venous tone, was calculated. Mean arterial pressure (MAP), heart rate (HR), and MCFP were recorded from conscious rats. Postsynaptic adrenergic responsiveness was assessed by constructing cumulative dose-response curves to norepinephrine (NE). RESULTS MAP was not significantly affected by ovariectomy (Sham 127 +/- 6 mm Hg vs. OVX 130 +/- 3 mm Hg). HR also was not different between groups (Sham 409 +/- 11 bpm vs. OVX 399 +/- 12 bpm). Conversely, MCFP was significantly, but moderately, increased in OVX SHR (Sham 5.2 +/- 0.2 mm Hg vs. OVX 5.9 +/- 0.2 mm Hg). Ganglionic blockade produced marked decreases in MAP, HR, and MCFP in both groups; however, the responses were not different between groups. Infusion of NE caused dose-dependent increases in MAP and MCFP. There were no statistically significant differences in these responses between Sham and OVX SHR. CONCLUSION Endogenous ovarian hormones effect a small reduction in MCFP. This effect does not appear to be mediated by adrenergic mechanisms.
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Vernerová Z, Kramer HJ, Bäcker A, Červenka L, Opočenský M, Husková Z, Vaňourková Z, Eis V, Chábová VČ, Tesař V, Malý J, Vaněčková I. Late-onset endothelin receptor blockade in hypertensive heterozygous REN-2 transgenic rats. Vascul Pharmacol 2008; 48:165-73. [DOI: 10.1016/j.vph.2008.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Accepted: 01/29/2008] [Indexed: 10/22/2022]
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