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Monneret D, Stavis RL. Umbilical Cord Blood Gas Pairs with Near-Identical Results: Probability of Arterial or Venous Source. Am J Perinatol 2024; 41:1521-1531. [PMID: 37579762 DOI: 10.1055/s-0043-1772228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
OBJECTIVE In studies of concomitant arterial-venous umbilical cord blood gases (CAV-UBGs), approximately 10% of technically valid samples have very similar pH and/or pCO2 values and were probably drawn from the same type of blood vessel. Without a way to objectively determine the source in these cases, it has been argued that most of these same-source CAV-UBGs are venous because the vein is larger and more easily sampled than the artery. This study aimed to calculate the probability of an arterial (ProbAS) or venous source (ProbVS) of same-source CAV-UBGs in the clinically and medicolegally important pH range of 6.70 to 7.25 using a statistical predictive model based on the cord blood gas values. STUDY DESIGN Starting with a dataset of 56,703 CAV-UBGs, the ProbAS, ProbVS, and respective 95% confidence intervals (CIs) were calculated for the 241 sample pairs with near-identical pH, pCO2, and pO2 values and a pH of 6.70 to 7.25. Using a previously validated generalized additive model, the source was categorized as: Probable Arterial or Highly Probable Arterial if the ProbAS and CIs were >0.5 or >0.8, respectively; Probable Venous or Highly Probable Venous if the ProbVS and CIs were >0.5 or >0.8, respectively; or Indeterminant if the CIs encompassed ProbAS/VS = 0.5. RESULTS A total of 39% of the same-source CAV-UBGs were Probable Arterial, 56% were Probable Venous, and 5% were Indeterminant. However, considering samples with a pH ≤7.19, 80% were Probable Arterial and 16% were Probable Venous. Considering the Highly Probable categories, the more acidemic specimens were 9 times more likely to be arterial than venous. Similarly, CAV-UBGs with pCO2 > 8.2 kPa (62 mm Hg) or pO2 ≤ 1.9 kPa (14 mm Hg) were more likely to be in the arterial rather than the venous categories. CONCLUSION Same-source CAV-UBGs in the more acidemic, hypercarbic, or hypoxemic ranges are more likely to be arterial than venous. KEY POINTS · Umbilical cord arterial/venous gases (CAV-UBGs) with similar values are thought to be mainly venous.. · A validated statistical model was used to predict the probability an arterial or venous source.. · CAV-UBGs with very similar values and pH > 7.19 are likely venous; however, those with pH ≤ 7.19 and/or pCO2 > 8.2 kPa and/or pO2 ≤1.9 kPa are more likely arterial..
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Affiliation(s)
- Denis Monneret
- Service de Biochimie et Biologie Moléculaire, Laboratoire de Biologie Médicale Multi-Sites (LBMMS), Hospices Civils de Lyon (HCL), Lyon, France
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Sengul M, Karadas B, Acar-Sahan S, Simsek F, Horoz E, Özok IC, Temiz T. Functional and Histological Changes in Umbilical Artery and Myometrium Isolated from IUGR Complicated Pregnancies. Fetal Pediatr Pathol 2023; 42:845-859. [PMID: 37578058 DOI: 10.1080/15513815.2023.2245892] [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: 05/04/2023] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 08/15/2023]
Abstract
Objective: To investigate the relaxation responses mediated by L-type Ca2+ channels and big-conductance Ca2+-activated K+ (BKCa) channels and histological changes in the human umbilical artery (HUA) and myometrium smooth muscle isolated from pregnancies complicated with intrauterine growth restriction (IUGR).Methods: The muscle reactivity and the histology of the smooth muscle of the HUA and myometrium retrieved from 14 women with IUGR and 14 controls were investigated by the isolated tissue bath and immunohistochemical method.Results: In HUA, the maximum relaxation responses and pD2 values of nifedipine and NS11021 (BKCa channel opener) were significantly increased and significant histopathological changes are observed in the IUGR group.Conclusions: The pathogenesis of IUGR might be associated with the impairment in the functional responses of L-type Ca2+ channels and BKCa channels in HUA smooth muscle. The increased staining of myometrium and UC with HIF-1α in IUGR may indicate apoptosis, histological damage, and impaired fetal growth.
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Affiliation(s)
- Mustafa Sengul
- Department of Obstetrics and Gynecology Izmir, Izmir Katip Celebi University Faculty of Medicine, Turkey
| | - Baris Karadas
- Department of Pharmacology Izmir, Izmir Katip Celebi University Faculty of Medicine, Turkey
| | - Selin Acar-Sahan
- Department of Pharmacology Izmir, Izmir Katip Celebi University Faculty of Medicine, Turkey
| | - Fatma Simsek
- Department of Histology and Embryology Izmir, Izmir Katip Celebi University Faculty of Medicine, Turkey
| | - Ersan Horoz
- Department of Pharmacology Izmir, Izmir Katip Celebi University Faculty of Medicine, Turkey
| | - Işık Cem Özok
- Department of Pharmacology Izmir, Izmir Katip Celebi University Faculty of Medicine, Turkey
| | - Tijen Temiz
- Department of Pharmacology Izmir, Izmir Katip Celebi University Faculty of Medicine, Turkey
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Karadas B, Acar-Sahan S, Kantarci S, Uysal N, Horoz E, Kaya-Temiz T. Comparison of relaxant effects of nifedipine and NS11021 on isolated umbilical arteries of healthy and preeclamptic pregnant women. Eur J Obstet Gynecol Reprod Biol 2023; 280:168-173. [PMID: 36508854 DOI: 10.1016/j.ejogrb.2022.12.009] [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: 06/09/2022] [Revised: 11/08/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Potassium (K+) channel openers and calcium (Ca2+) channel blockers are currently used to treat acute severe hypertension in pregnancy. We aimed to investigate the vasorelaxant effect of NS11021, a potent and specific big-conductance Ca2+-activated K+ (BKCa) channel activator, and to compare it with the vasorelaxant effect of nifedipine on human umbilical arteries (HUAs) isolated from healthy and preeclamptic pregnants. STUDY DESIGN A total of 29 HUAs were isolated immediately after delivery from 14 healthy and 15 preeclamptic pregnant with severe features. The concentration-dependent relaxation responses were obtained to nifedipine and NS11021 on HUAs precontracted with endothelin-1 (ET-1) (10-8 M) in an isolated tissue bath. RESULTS Both nifedipine and NS11021 caused concentration-dependent relaxation responses in HUAs from healthy and preeclamptic pregnants. While the maximum responses (Emax) and pD2 values of nifedipine did not change significantly in both groups, the Emax and pD2 values of NS11021 were significantly decreased in the preeclampsia group (Emax ± SEM; %75.57 ± 4.53 and %43.75 ± 14.00 and pD2 ± SEM; 6.92 ± 0.26 and 5.24 ± 0.53 respectively, p < 0.05). In addition, the pD2 value of NS11021 was not significantly different from that of nifedipine in the control group, but decreased significantly in the preeclampsia group (pD2 ± SEM 7.1 ± 0.41 and 5.2 ± 0.53, p < 0.05, respectively). CONCLUSIONS Efficacy and potency of NS11021 decreased in HUAs from preeclamptic pregnants. Also, NS11021 is less potent than nifedipine in the preeclampsia group. BKCa channels may have a role in the pathogenesis of preeclampsia, however, further experimental studies are needed to elucidate that.
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Affiliation(s)
- Baris Karadas
- Izmir Katip Celebi University Faculty of Medicine, Department of Pharmacology Izmir, Turkey.
| | - Selin Acar-Sahan
- Izmir Katip Celebi University Faculty of Medicine, Department of Pharmacology Izmir, Turkey.
| | - Sercan Kantarci
- University of Health Sciences Tepecik Training and Research Hospital Department of Obstetrics and Gynecology Izmir, Turkey
| | - Nusret Uysal
- Izmir Katip Celebi University Faculty of Medicine, Department of Pharmacology Izmir, Turkey
| | - Ersan Horoz
- Izmir Katip Celebi University Faculty of Medicine, Department of Pharmacology Izmir, Turkey.
| | - Tijen Kaya-Temiz
- Izmir Katip Celebi University Faculty of Medicine, Department of Pharmacology Izmir, Turkey.
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Feng X, Zhang Y, Tao J, Lu L, Zhang Y, Liu J, Zhao M, Guo J, Zhu D, Zhu J, Xu Z. Comparison of Vascular Responses to Vasoconstrictors in Human Placenta in Preeclampsia between Preterm and Later Term. Curr Pharm Biotechnol 2020; 21:727-733. [PMID: 31845629 DOI: 10.2174/1389201021666191217114111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 11/02/2019] [Accepted: 11/11/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND Placental blood vessels play important roles in maternal-fetal circulation. Although pathologic mechanisms of preeclampsia are unclear, it is known that placental vascular dysfunction could contribute to pregnant hypertension. However, placental micro-vessel function or dysfunction at preterm has not been investigated. METHODS Human placentas from normal and preeclamptic pregnancies at preterm and term were obtained. Placental micro-vessels were used for determining vascular tension and responses to various vasoconstrictors as well as intracellular calcium store capability. It was the first time to show vascular responses in placental arteries to angiotensin II, endothelin-1, and other vascular drugs at preterm. RESULTS Compared to the control, placental vascular contractile responses to angiotensin II and caffeine were significantly decreased, while placental vascular responses to KCl, endothelin-1, and bradykinin were not significantly altered in the later term group in preeclampsia. In comparison of placental micro-vessel tension between the preterm and later term, caffeine- and serotonin-induced vascular contractions were significantly weaker in the preterm than that in the later term. On the contrary, vascular response to angiotensin II was increased in the preterm preeclampsia, while KCl-, endothelin-1, and bradykinin-mediated placental vessel responses in the preterm preeclampsia were similar to that in later term preeclampsia. CONCLUSION New data showed that micro-vessel responses to angiotensin II and serotonin, not endothelin- 1 or bradykinin, were significantly reduced in the human placentas at preterm, and intracellular Ca2+ store capacity was damaged too, providing important information on possible contributions of placental vascular dysfunction to pregnant hypertension.
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Affiliation(s)
- Xueqin Feng
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Yumeng Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Jianying Tao
- Department of Obstetrics and Gynecology, Suzhou Municipal Hospital, Suzhou, Jiangsu, China
| | - Likui Lu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Yingying Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Jingliu Liu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Meng Zhao
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Jun Guo
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Dan Zhu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Jianguo Zhu
- Department of Pharmacy, First Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Zhice Xu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, Jiangsu, China
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Salinas-Torres VM, Salinas-Torres RA, Cerda-Flores RM, Gallardo-Blanco HL, Martínez-de-Villarreal LE. A clinical-pathogenetic approach on associated anomalies and chromosomal defects supports novel candidate critical regions and genes for gastroschisis. Pediatr Surg Int 2018; 34:931-943. [PMID: 30094464 DOI: 10.1007/s00383-018-4331-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/02/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Gastroschisis has been assumed to have a low rate of syndromic and primary malformations. We aimed to systematically review and explore the frequency and type of malformations/chromosomal syndromes and to identify significant biological/genetic roles in gastroschisis. METHODS Population-based, gastroschisis-associated anomalies/chromosomal defects published 1950-2018 (PubMed/MEDLINE) were independently searched by two reviewers. Associated anomalies/chromosomal defects and selected clinical characteristics were subdivided and pooled by race, system/region, isolated, and associated cases (descriptive analysis and chi-square test were performed). Critical regions/genes from representative chromosomal syndromes including an enrichment analysis using Gene Ontology Consortium/Panther Classification System databases were explored. Fisher's exact test with False Discovery Rate multiple test correction was performed. RESULTS Sixty-eight articles and 18525 cases as a base were identified (prevalence of 17.9 and 3% for associated anomalies/chromosomal defects, respectively). There were 3596 associated anomalies, prevailing those cardiovascular (23.3%) and digestive (20.3%). Co-occurring anomalies were associated with male, female, American Indian, Caucasian, prenatally diagnosed, chromosomal defects, and mortality (P < 0.00001). Gene clusters on 21q22.11 and 21q22.3 (KRTAP), 18q21.33 (SERPINB), 18q22.1 (CDH7, CDH19), 13q12.3 (FLT1), 13q22.1 (KLF5), 13q22.3 (EDNRB), and 13q34 (COL4A1, COL4A2, F7, F10) were significantly related to biological processes: blood pressure regulation and/or vessel integrity, angiogenesis, coagulation, cell-cell and/or cell-matrix adhesion, dermis integrity, and wound healing (P < 0.05). CONCLUSIONS Our findings suggest that gastroschisis may result from the interaction of several chromosomal regions in an additive manner as a pool of candidate genes were identified from critical regions supporting a role for vascular disruption, thrombosis, and mesodermal deficiency in the pathogenesis of gastroschisis.
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Affiliation(s)
- Victor M Salinas-Torres
- Departamento de Genética, Facultad de Medicina y Hospital Universitario José Eleuterio González, Universidad Autónoma de Nuevo León, Ave. Madero y Gonzalitos S/N Col. Mitras Centro, CP 64460, Monterrey, Nuevo León, México.
| | - Rafael A Salinas-Torres
- Departamento de Sistemas y Computación, Instituto Tecnológico de Tijuana, Calzada del Tecnológico S/N Fracc. Tomas Aquino, CP 22414, Tijuana, Baja California, México
| | - Ricardo M Cerda-Flores
- Universidad Autónoma de Nuevo León, Facultad de Enfermería, Dr. José Eleuterio González 1500, Mitras Centro, CP 64460, Monterrey, Nuevo León, México
| | - Hugo L Gallardo-Blanco
- Departamento de Genética, Facultad de Medicina y Hospital Universitario José Eleuterio González, Universidad Autónoma de Nuevo León, Ave. Madero y Gonzalitos S/N Col. Mitras Centro, CP 64460, Monterrey, Nuevo León, México
| | - Laura E Martínez-de-Villarreal
- Departamento de Genética, Facultad de Medicina y Hospital Universitario José Eleuterio González, Universidad Autónoma de Nuevo León, Ave. Madero y Gonzalitos S/N Col. Mitras Centro, CP 64460, Monterrey, Nuevo León, México
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Lorigo M, Mariana M, Feiteiro J, Cairrao E. How is the human umbilical artery regulated? J Obstet Gynaecol Res 2018; 44:1193-1201. [PMID: 29727040 DOI: 10.1111/jog.13667] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 03/31/2018] [Indexed: 01/12/2023]
Abstract
The purpose of this review is to present an update of the main mechanisms involved in the physiological regulation of contraction and relaxation of the human umbilical artery (HUA) smooth muscle cells. A literature review was performed based on the analysis of papers available on PubMed. The most important and relevant studies regarding the regulation of the HUA are presented in this article. The vascular smooth muscle is a highly specialized structure, whose main function is to regulate the vascular tonus. This is controlled by a balance between the cellular signaling pathways that mediate contraction and relaxation. The cells responsible for the contractile property of this muscle are the smooth muscle cells (SMC), and an excellent source of these cells is the HUA, involved in fetoplacental circulation. Since the umbilical blood vessels are not innervated, the HUA tonus is modulated by vasoactive substances that regulate the contractile process. The main vasoactive substances that induce contraction are serotonin, histamine, thromboxane, bradykinin, endothelin 1 and prostaglandin F2α, that are linked to the activation of proteins Gq and Gi/0 . On the other hand, the main vasorelaxation mechanisms are the activation of adenyl and guanil cyclases, potassium channels and the inhibition of calcium channels. The SMC from the HUA allow the study of different cellular mechanisms and their functions. Therefore, these cells are an important tool to study the mechanisms regulating the contractility of this artery, allowing to detect potential therapeutic targets to treat HUA disorders (gestational hypertension and pre-eclampsia).
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Affiliation(s)
- Margarida Lorigo
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Melissa Mariana
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Joana Feiteiro
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Elisa Cairrao
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
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Mohammed R, Cavallaro G, Kessels CGA, Villamor E. Functional differences between the arteries perfusing gas exchange and nutritional membranes in the late chicken embryo. J Comp Physiol B 2015; 185:783-96. [PMID: 26119481 PMCID: PMC4568027 DOI: 10.1007/s00360-015-0917-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 05/28/2015] [Accepted: 06/10/2015] [Indexed: 11/30/2022]
Abstract
The chicken extraembryonic arterial system comprises the allantoic arteries, which irrigate the gas exchange organ (the chorioallantoic membrane, CAM) and the yolk sac (YS) artery, which irrigates the nutritional organ (the YS membrane). We compared, using wire myography, the reactivity of allantoic and YS arteries from 19-day chicken embryos (total incubation 21 days). The contractions induced by KCl, the adrenergic agonists norepinephrine (NE, nonselective), phenylephrine (α1), and oxymetazoline (α2), electric field stimulation (EFS), serotonin, U46619 (TP receptor agonist), and endothelin (ET)-1 and the relaxations induced by acetylcholine (ACh), sodium nitroprusside (SNP, NO donor), forskolin (adenylate cyclase activator), and isoproterenol (β-adrenergic agonist) were investigated. Extraembryonic allantoic arteries did not show α-adrenergic-mediated contraction (either elicited by exogenous agonists or EFS) or ACh-induced (endothelium-dependent) relaxation, whereas these responses were present in YS arteries. Interestingly, the intraembryonic segment of the allantoic artery showed EFS- and α-adrenergic-induced contraction and ACh-mediated relaxation. Moreover, glyoxylic acid staining showed the presence of catecholamine-containing nerves in the YS and the intraembryonic allantoic artery, but not in the extraembryonic allantoic artery. Isoproterenol- and forskolin-induced relaxation and ET-1-induced contraction were higher in YS than in allantoic arteries, whereas serotonin- and U46619-induced contraction and SNP-induced relaxation did not significantly differ between the two arteries. In conclusion, our study demonstrates a different pattern of reactivity in the arteries perfusing the gas exchange and the nutritional membranes of the chicken embryo.
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Affiliation(s)
- Riazudin Mohammed
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), Research Institute Growth and Development (GROW) and Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, P. Debyelaan 25, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Giacomo Cavallaro
- Neonatal Intensive Care Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Carolina G A Kessels
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), Research Institute Growth and Development (GROW) and Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, P. Debyelaan 25, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Eduardo Villamor
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), Research Institute Growth and Development (GROW) and Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, P. Debyelaan 25, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands.
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The effects of particulate ambient air pollution on the murine umbilical cord and its vessels: A quantitative morphological and immunohistochemical study. Reprod Toxicol 2012; 34:598-606. [DOI: 10.1016/j.reprotox.2012.08.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 08/14/2012] [Accepted: 08/20/2012] [Indexed: 02/03/2023]
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Compeer MG, Suylen DP, Hackeng TM, De Mey JG. Endothelin-1 and -2: Two amino acids matter. Life Sci 2012; 91:607-12. [DOI: 10.1016/j.lfs.2012.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 11/29/2022]
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Galajda Z, Balla J, Szentmiklosi AJ, Biro T, Czifra G, Dobrosi N, Cseppento A, Patonay L, Roszer T, Balla G, Popescu LM, Lekli I, Tosaki A. Histamine and H1 -histamine receptors faster venous circulation. J Cell Mol Med 2012; 15:2614-23. [PMID: 21199332 PMCID: PMC4373430 DOI: 10.1111/j.1582-4934.2010.01254.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The study has analysed the action of histamine in the rabbit venous system and evaluated its potential role in contraction during increased venous pressure. We have found that a great variety exists in histamine sensitivity and H(1) -histamine receptor expression in various types of rabbit veins. Veins of the extremities (saphenous vein, femoral vein, axillary vein) and abdomen (common iliac vein, inferior vena cava) responded to histamine by a prominent, concentration-dependent force generation, whereas great thoracic veins (subclavian vein, superior vena cavas, intrathoracic part of inferior vena cava) and a pelvic vein (external iliac vein) exhibited slight sensitivity to exogenous histamine. The lack of reactivity to histamine was not due to increased activity of nitric oxide synthase (NOS) or heme oxygenase-1. H(1) -histamine receptor expression of veins correlated well with the histamine-induced contractions. Voltage-dependent calcium channels mediated mainly the histamine-induced force generation of saphenous vein, whereas it did not act in the inferior vena cava. In contrast, the receptor-operated channels were not involved in this response in either vein. Tyrosine phosphorylation occurred markedly in response to histamine in the saphenous vein, but not in the inferior vena cava. Histamine induced a prominent ρ kinase activation in both vessels. Protein kinase C and mitogen-activated protein kinase (MAPK) were not implicated in the histamine-induced intracellular calcium sensitization. Importantly, transient clamping of the femoral vein in animals caused a short-term constriction, which was inhibited by H(1) -histamine receptor antagonist in vivo. Furthermore, a significantly greater histamine immunopositivity was detected in veins after stretching compared to the resting state. We conclude that histamine receptor density adapts to the actual requirements of the circulation, and histamine liberated by the venous wall during increased venous pressure contributes to the contraction of vessels, providing a force for the venous return.
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Affiliation(s)
- Zoltan Galajda
- Department of Surgery, Institute of Vascular Surgery, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
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Abstract
The 21-amino-acid peptide ET-1 (endothelin-1) regulates a diverse array of physiological processes, including vasoconstriction, angiogenesis, nociception and cell proliferation. Most of the effects of ET-1 are associated with an increase in intracellular calcium concentration. The calcium influx and mobilization pathways activated by ET-1, however, vary immensely. The present review begins with the basics of calcium signalling and investigates the different ways intracellular calcium concentration can increase in response to a stimulus. The focus then shifts to ET-1, and discusses how ET receptors mobilize calcium. We also examine how disease alters calcium-dependent responses to ET-1 by discussing changes to ET-1-mediated calcium signalling in hypertension, as there is significant interest in the role of ET-1 in this important disease. A list of unanswered questions regarding ET-mediated calcium signals are also presented, as well as perspectives for future research of calcium mobilization by ET-1.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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Mildenberger E, Biesel B, Siegel G, Versmold HT. Endothelin B Receptors on Vascular Smooth Muscle Cells of the Human Umbilical Vein Mediate Vasoconstriction. Fetal Diagn Ther 2008; 24:67-70. [DOI: 10.1159/000132410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Accepted: 04/22/2007] [Indexed: 11/19/2022]
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Wada Y, Takahashi W, Latifpour J, Yamada G, Kai N, Honda J, Nakanishi J, Weiss RM. Regional differences in the functional and biochemical properties of endothelin receptor subtypes in the rabbit prostatic urethra. BJU Int 2007; 100:430-7. [PMID: 17559559 DOI: 10.1111/j.1464-410x.2007.07064.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To examine the regional differences in the functional (pharmacological) and biochemical properties of endothelin (ET) receptors in the rabbit prostatic urethra. MATERIALS AND METHODS The properties of ET receptors in 6-month-old male rabbit prostatic urethras were examined using isolated muscle-bath and radioligand receptor-binding techniques. Using plasma membrane suspensions, saturation and inhibition experiments with [(125)I]ET-1 and unlabelled agonists and antagonists (ET(A)-selective antagonist BQ123, and ET(B)-selective agonist sarafotoxin 6c, STX6c) were done to determine the ET receptor densities and their subtype specificities in the different regions of the urethra. RESULTS The ETs (ET-1 and ET-3) produced significant concentration-dependent contractile responses in the smooth muscle strips from the different regions of the urethra. Although the maximum contractile responses induced by ET-1 were similar in the different regions, the maximum contractile responses induced by ET-3 were greater in the distal region than in the proximal or middle regions, suggesting that the contractile response to ET-1 is more potent than that to ET-3 in all regions, and that there are region-specific differences in the responses to ET-3 but not ET-1. Moreover, the ET-3-induced contractile response was suppressed by BQ788 (a selective antagonist of the ET(B) receptor) suggesting that the ET(B) receptor subtype contributes to the contractile responses mediated by ET-3. The ET receptors were expressed in higher concentrations in the distal than in the proximal or middle regions. BQ123 and STX6c inhibited [(125)I]ET-1 binding in all regions with high and low affinity constants, indicating the presence of both ET(A) and ET(B) receptor subtypes. The proportions of high-affinity binding sites for BQ123, representing ET(A) receptors, were approximately 68%, 63% and 42% in the proximal, middle and distal regions, respectively. By contrast, the proportions of high-affinity binding sites for STX6c, representing ET(B) receptors, were approximately 27%, 35% and 52% in the proximal, middle, and distal regions, respectively. These data indicate the presence of regional differences in the densities and subtype specificities of ET receptor subtypes, and the existence of regional differences in the rabbit prostatic urethra. CONCLUSION The results suggest regional differences in ET(B) receptor subtypes that mediate contractile responses to ET-3, reflecting differences in the densities and specificities of the ET receptor subtypes in the rabbit prostatic urethra.
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Affiliation(s)
- Yoshihiro Wada
- Department of Urology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
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14
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Chester AH, Azam R, Felkin LE, George R, Brand N. Correlation between vascular responsivensss and expression of novel transcripts of the ETA-receptor in human vascular tissue. Vascul Pharmacol 2007; 46:181-7. [PMID: 17126612 DOI: 10.1016/j.vph.2006.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2006] [Revised: 09/01/2006] [Accepted: 09/26/2006] [Indexed: 11/26/2022]
Abstract
Alternatively spliced endothelin (ET-1) receptor transcripts have been identified, but their significance to the functional effects of ET-1 has not been established. We have investigated the presence and influence of alternatively spliced ET(A) receptor transcripts on ET-1 mediated contraction of segments of human saphenous vein. The expression of ET(A) receptor transcripts was examined with quantitative reverse transcription-polymerase chain reaction (qPCR) studies, while the response of veins to ET-1 was tested with in vitro organ bath techniques. The expression of four different transcripts for the ET(A) receptor, in which either exon 3 is spliced out (Delta3), exon 4 is spliced out (Delta4), both 3 and 4 spliced out (Delta3,4) and when both exons 2 and 4 (Delta2,4) are spliced out were identified. Functional studies showed that a lack of efficacy and potency of ET-1 is associated with a significantly lower expression of the Delta3,4 transcript. ET(A) receptor antagonism was insurmountable in samples that had lower levels of the Delta3,4 transcript, while samples from patients with higher expression of the Delta3,4 showed surmountable antagonism with BQ123. These results suggest that there is a genetic basis for the variability between individuals for the contractile effect of ET-1 at ET(A) receptors.
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Affiliation(s)
- Adrian H Chester
- Imperial College London, Heart Science Centre, Harefield Hospital, Harefield, Middlesex, UB9 6JH, United Kingdom.
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15
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Laflamme K, Roberge CJ, Pouliot S, D'Orléans-Juste P, Auger FA, Germain L. Tissue-engineered human vascular media produced in vitro by the self-assembly approach present functional properties similar to those of their native blood vessels. ACTA ACUST UNITED AC 2006; 12:2275-81. [PMID: 16968167 DOI: 10.1089/ten.2006.12.2275] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have developed a tissue-engineering approach for the production of a completely biological blood vessel from cultured human cells. In the present study, we took advantage of this tissue-engineering method to demonstrate that it can be used to reproduce the subtle differences in the expression of receptors present on the media of native human blood vessels. Indeed, a small percentage (3 of 18) of native human umbilical cord veins (HUCVs) responded to endothelin, the most powerful vasopressor agent known to date, via both endothelin A (ET(A)) and endothelin B (ET(B)) receptor activation. In contrast, most HUCVs tested responded to ET via ET(A) receptor activation only. Tissue-engineered vascular media (TEVM) were next reconstructed by using vascular smooth muscle cells (VSMCs) isolated and cultured from HUCVs expressing both ET(A) and ET(B) receptors to determine the functional integrity of our TEVM model. The reconstructed TEVM presents an endothelin response similar to that of respective HUCVs from which VSMCs were isolated. Reverse transcriptase polymerase chain reaction on TEVM reconstructed in vitro correlated these vasocontractile profiles by showing the presence of messenger RNA for both ET(A) and ET(B) receptors. Taken together with recently published results on TEVM expressing only ET(A) receptor, these results show that our reconstructed TEVM present a similar ET response profile as the blood vessel from which the VSMCs were isolated and cultured. These findings indicate that subtle differences, such as receptor expression, are preserved in the reconstructed tissue. Therefore, our TEVM offers a valuable human in vitro model with which to study the functionality of human blood vessels, such as their vasoactive response, or to perform pharmacologic studies.
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Affiliation(s)
- Karina Laflamme
- Laboratoire d'Organogénèse Expérimentale, Hôpital du Saint-Sacrement du CHA, and Department of Surgery, Laval University, Québec, Canada
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16
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Tirapelli CR, Casolari DA, Yogi A, Montezano AC, Tostes RC, Legros E, D'Orléans-Juste P, de Oliveira AM. Functional characterization and expression of endothelin receptors in rat carotid artery: involvement of nitric oxide, a vasodilator prostanoid and the opening of K+ channels in ETB-induced relaxation. Br J Pharmacol 2005; 146:903-12. [PMID: 16151434 PMCID: PMC1751214 DOI: 10.1038/sj.bjp.0706388] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Revised: 05/05/2005] [Accepted: 08/05/2005] [Indexed: 11/09/2022] Open
Abstract
We aimed to functionally characterize endothelin (ET) receptors in the rat carotid artery. mRNA and protein expressions of both ETA and ETB receptors, evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and Western immunoblotting, were detected in carotid segments. Immunohistochemical assays showed that ETB receptors are expressed in the endothelium and smooth muscle cells, while ETA receptors are expressed only in the smooth muscle cells. In endothelium-denuded vessels, levels of ETB receptor mRNA were reduced. Vascular reactivity experiments, using standard muscle bath procedures, showed that ET-1 induces contraction in endothelium-intact and -denuded carotid rings in a concentration-dependent manner. Endothelial removal enhanced ET-1-induced contraction. BQ123 and BQ788, selective antagonists for ETA and ETB receptors, respectively, produced concentration-dependent rightward displacements of the ET-1 concentration-response curves. IRL1620, a selective agonist for ETB receptors, induced a slight vasoconstriction that was abolished by BQ788, but not affected by BQ123. IRL1620-induced contraction was augmented after endothelium removal. ET-1 concentration dependently relaxed phenylephrine-precontracted rings with intact endothelium. The relaxation was augmented in the presence of BQ123, reduced in the presence of BQ788 and completely abolished after endothelium removal. IRL1620 induced vasorelaxation that was abolished by BQ788 and endothelium removal, but not affected by BQ123. Preincubation of intact rings with N(G)-nitro-L-arginine methyl ester (L-NAME), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), indomethacin or tetraethylammonium (TEA) reduced IRL1620-induced relaxation. The combination of L-NAME, indomethacin and TEA completely abolished IRL1620-induced relaxation while sulfaphenazole did not affect this response. 4-aminopyridine (4-AP), but not apamin, glibenclamide or charybdotoxin, reduced IRL1620-induced relaxation. The major finding of this work is that it firstly demonstrated functionally the existence of both ETA and ETB vasoconstrictor receptors located on the smooth muscle of rat carotid arteries and endothelial ETB receptors that mediated vasorelaxation via NO-cGMP pathway, vasodilator cyclooxygenase product(s) and the activation of voltage-dependent K+ channels.
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MESH Headings
- Animals
- Blotting, Western
- Carotid Arteries/drug effects
- Carotid Arteries/metabolism
- Carotid Arteries/physiology
- Endothelin A Receptor Antagonists
- Endothelin B Receptor Antagonists
- Endothelin-1/pharmacology
- Endothelins/pharmacology
- Endothelium, Vascular/physiology
- Endothelium-Dependent Relaxing Factors/physiology
- Gene Expression/drug effects
- Immunohistochemistry
- Male
- Nitric Oxide/physiology
- Oligopeptides/pharmacology
- Peptide Fragments/pharmacology
- Peptides, Cyclic/pharmacology
- Piperidines/pharmacology
- Potassium Channels/physiology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptor, Endothelin A/genetics
- Receptor, Endothelin A/physiology
- Receptor, Endothelin B/genetics
- Receptor, Endothelin B/physiology
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Vasodilation/drug effects
- Vasodilation/physiology
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Affiliation(s)
- Carlos R Tirapelli
- Department of Pharmacology, Faculty of Medicine of Ribeirão Preto, University of São Paulo (USP), SP, Brazil
| | - Debora A Casolari
- Department of Pharmacology, Institute of Biomedical Sciences, USP, São Paulo, SP, Brazil
| | - Alvaro Yogi
- Department of Pharmacology, Institute of Biomedical Sciences, USP, São Paulo, SP, Brazil
| | - Augusto C Montezano
- Department of Pharmacology, Institute of Biomedical Sciences, USP, São Paulo, SP, Brazil
| | - Rita C Tostes
- Department of Pharmacology, Institute of Biomedical Sciences, USP, São Paulo, SP, Brazil
| | - Eurode Legros
- Department of Pharmacology, Medical School, Institut de pharmacologie de Sherbrooke, Universite de Sherbrooke, QC, Canada
| | - Pedro D'Orléans-Juste
- Department of Pharmacology, Medical School, Institut de pharmacologie de Sherbrooke, Universite de Sherbrooke, QC, Canada
| | - Ana M de Oliveira
- Department of Physics and Chemistry, Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, USP, Ribeirão Preto, SP, Brazil
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17
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D'Orléans-Juste P, Labonté J, Bkaily G, Choufani S, Plante M, Honoré JC. Function of the endothelinB receptor in cardiovascular physiology and pathophysiology. Pharmacol Ther 2002; 95:221-38. [PMID: 12243796 DOI: 10.1016/s0163-7258(02)00235-8] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
One of the two receptors by which the potent vasoactive effects of endothelin (ET)-1 are mediated is the ET(B) receptor (ET(BR)), which is found in several tissues, but, more importantly from a cardiovascular point of view, on the endothelial cell. The endothelial cell also has the unique capability of releasing ET-1, as well as other factors, such as the endothelial-derived relaxing factors and prostacyclin, which counteract the myotropic effects of the peptide. The secretory and contractile responses to ET-1 rely on G-protein-coupled ET(BR)s, as well as ET(A)-G-protein-coupled receptor-like proteins. The mitogenic properties of ET-1 via ET(A) receptors (ET(AR)s) coupled to mitogen-activated protein kinases and tyrosine kinases on the vascular smooth muscle may occur in conjunction with the anti-apoptotic characteristics of the endothelial ET(BR)s. Interestingly, most of the relevant antagonists and agonists for both ET(AR)s and ET(BR)s have been developed by the pharmaceutical industry. This highlights the therapeutical potential of compounds that act on ET receptors. In normal as well as in physiopathological conditions, the ET(BR) plays an important role in the control of vascular tone, and must be taken into account when using ET receptor antagonists for the treatment of cardiovascular diseases. For the management of congestive heart failure, renal failure and primary pulmonary hypertension, the most recent literature supports the use of selective ET(AR) antagonists rather than mixed antagonists of ET(AR)s and ET(BR)s. Nonetheless, validation of this view will have to await the first clinical trials comparing the actions of ET(A) to mixed ET(A)/ET(B) receptor antagonists.
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Affiliation(s)
- P D'Orléans-Juste
- Department of Pharmacology, Institut de Pharmacologie de Sherbrooke, Medical School, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, J1H 5N4, Québec, Canada.
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18
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Conant AR, Oo AY, Dashwood MR, Collard K, Chester MR, Dihmis WC, Simpson AWM. Endothelin receptors in cultured and native human radial artery smooth muscle. J Cardiovasc Pharmacol 2002; 39:130-41. [PMID: 11743235 DOI: 10.1097/00005344-200201000-00014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In human vascular smooth muscle cells endothelin-1, acting at both endothelin A and endothelin B receptors, has been demonstrated to be both a potent vasoconstrictor and mitogen. Our aim was to study the functional expression of endothelin receptors in human radial artery smooth muscle using both native tissue and cultured cells (RASMCs). Radial artery smooth muscle cells were cultured from arterial explants and loaded with the calcium fluorescent dye fura-2. Cells responded to endothelin-1 and a variety of other vasoconstrictors with rises in cytoplasmic calcium ([Ca2+]c). Arterial rings responded to endothelin-1 with an increase in tension. The response of both cells and arterial rings to endothelin-1 was characterized using the selective endothelin A receptor antagonist BQ123 and the endothelin B receptor antagonist BQ788. The RASMCs were found to express [Ca2+]c responses consistent with the expression of only the endothelin A receptor. Endothelin-1-mediated vasoconstriction in radial artery rings was unaffected by BQ788 but was completely blocked by BQ123. Using the selective radioligands [125I]-PD151242 and [125I]-BQ3020 and a combination of in vitro receptor autoradiography and isolated cell preparations, endothelin A receptors were confirmed to be present on RASMCs and on arterial sections, whereas endothelin B binding was barely detectable on native smooth muscle and on RASMCs.
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Affiliation(s)
- Alan R Conant
- Cardiothoracic Center, Liverpool NHS Trust, Liverpool, UK.
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19
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Amadesi S, Varani K, Spisani L, Daniele C, Turini A, Agnello G, Zamboni P, Borea PA, Geppetti P. Comparison of prazosin, terazosin and tamsulosin: functional and binding studies in isolated prostatic and vascular human tissues. Prostate 2001; 47:231-8. [PMID: 11398170 DOI: 10.1002/pros.1067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Terazosin and tamsulosin are drugs currently used in the treatment of benign prostatic hypertrophy (BPH). The potency of these two alpha(1) receptor antagonists and that of prazosin to inhibit contractions induced by noradrenaline and the binding of [(3)H]-prazosin in human prostate and four different human arterial and venous vessels (saphenous and umbilical veins, renal and mesenteric arteries) was studied. METHODS By bioassay and binding studies, we examined the receptor affinities of different alpha(1) receptor antagonists in different human tissues. RESULTS pKb of terazosin, tamsulosin, and prazosin obtained in the prostatic tissues (8.15, 9.64, and 8.59, respectively) were not different from those obtained in the umbilical veins (8.07, 9.56, and 8.30, respectively), in the mesenteric artery (8.27, 10.29, and 9.01, respectively), renal artery (8.35, 10.13, and 8.76, respectively) and saphenous vein (7.8, 10.3, and 9.32, respectively). IC(50) (nM) of prazosin, terazosin, and tamsulosin obtained from binding studies in membrane preparations from prostate tissue were similar to those from umbilical veins, saphenous vein, and renal artery. CONCLUSIONS All of the evaluated drugs showed similar selectivity for prostatic vs. vascular tissues. Thus, different clinical profiles of the present drugs should not result from their differential affinity for prostatic versus vascular alpha(1)-adrenoceptors.
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MESH Headings
- Adrenergic alpha-1 Receptor Antagonists
- Adrenergic alpha-Antagonists/metabolism
- Adrenergic alpha-Antagonists/pharmacology
- Dose-Response Relationship, Drug
- Female
- Humans
- Kinetics
- Male
- Mesenteric Arteries/drug effects
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Norepinephrine/physiology
- Prazosin/analogs & derivatives
- Prazosin/metabolism
- Prazosin/pharmacology
- Prostate/drug effects
- Prostate/metabolism
- Prostate/physiology
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, alpha-1/physiology
- Renal Artery/drug effects
- Saphenous Vein/drug effects
- Sulfonamides/metabolism
- Sulfonamides/pharmacology
- Tamsulosin
- Umbilical Veins/drug effects
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Affiliation(s)
- S Amadesi
- Department of Experimental and Clinical Medicine, Pharmacology Unit, University of Ferrara, Ferrara, Italy
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20
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Laursen M, Bodelsson G, Stjernquist M. Atypical receptors mediate the response to endothelin-1 and sarafotoxin S6b in the human umbilical artery. Eur J Pharmacol 1998; 362:167-72. [PMID: 9874167 DOI: 10.1016/s0014-2999(98)00738-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The receptors mediating smooth muscle response to endothelin-1 and sarafotoxin S6b in the human umbilical artery were investigated in vitro. Both agonists induced contractions that were unaffected by the endothelin ET(B) receptor antagonist BQ 788 (10(-9), 10(-8), 10(-7) M). The non-selective endothelin ET(A/B) receptor antagonist PD 142893 (10(-7) M) decreased the contraction induced by endothelin-1. PD 142893 (10(-9) M) enhanced the contraction induced by sarafotoxin S6b whereas higher concentrations had no effect. Removing the endothelium did not affect the antagonising action of PD 142893 on endothelin-1-induced contractions while the enhancement of the sarafotoxin S6b-induced contraction was abolished. Sarafotoxin S6b induced relaxation in segments precontracted by 5-hydroxytryptamine and exposed to the endothelin ET(A) receptor antagonist BQ 123 (10(-7) M) and PD 142893 (10(-9) M) abolished this relaxation. These endothelial receptors seem neither to be classical endothelin ET(A) nor endothelin ET(B) receptors and they are not activated by endothelin-1.
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Affiliation(s)
- M Laursen
- Department of Obstetrics and Gynaecology, University Hospital, Malmö, Sweden
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21
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Reznik SE, Salafia CM, Lage JM, Fricker LD. Immunohistochemical localization of carboxypeptidases E and D in the human placenta and umbilical cord. J Histochem Cytochem 1998; 46:1359-68. [PMID: 9815277 DOI: 10.1177/002215549804601204] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Carboxypeptidase E (CPE) is highly concentrated in neuroendocrine tissues and is the only carboxypeptidase detected in mature secretory vesicles. Carboxypeptidase D (CPD), a carboxypeptidase with CPE-like activity, is widely distributed in tissues and is present in the trans-Golgi network. Previous work had shown that both CPE and CPD are expressed in the human placenta and that CPD is expressed at much higher levels than CPE. The present work provides evidence for the co-localization of CPE and CPD to basal plate extravillous trophoblasts and maternal uteroplacental vascular endothelial cells, chorionic villous endothelial cells, amnionic epithelial cells, and umbilical venous and arterial smooth muscle cells. Whereas the intensity of CPD immunostaining is similar in the placenta and umbilical cord, CPE staining in the placenta is much weaker than in the umbilical cord, suggesting that CPD plays a more important role in the processing of placental peptides. Immunoelectron microscopy of umbilical venous smooth muscle cells shows subcellular localization of both enzymes to the rough endoplasmic reticulum. In addition, CPE is present just subjacent to the cell membrane. The difference in cellular and subcellular localization between the two enzymes indicates that they perform distinct functions in the processing of placental peptides and proteins.
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Affiliation(s)
- S E Reznik
- Department of Pathology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York, USA
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22
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Rizzi A, Calo G, Battistini B, Regoli D. Contractile activity of endothelins and their precursors in human umbilical artery and vein: identification of distinct endothelin-converting enzyme activities. J Cardiovasc Pharmacol 1998; 31 Suppl 1:S58-61. [PMID: 9595400 DOI: 10.1097/00005344-199800001-00019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A number of studies using endothelin (ET) precursors, commonly termed big ETs, have revealed the presence of endothelin-converting enzyme (ECE) activity in various vascular and nonvascular preparations. Since then, more than one ECE has been cloned. It has also been observed that big ET-1 and big ET-3 are not converted by the same enzyme. The ECE responsible for big ET-3 conversion is rarely present because big ET-3 does not induce a contractile response in most isolated preparations tested. In this study we characterized ECE activities present in two human preparations, the umbilical artery and vein, testing the contractile activities of the three human Big ETs in the presence or absence of phosphoramidon, a dual ECE/neutral endopeptidase inhibitor. The results show that human big ET-1(1-38) is 6.3-fold more potent than big ET-2(1-38) in the human umbilical artery (an ETA preparation), whereas big ET-1 is equipotent to big ET-2 in the vein (which contains ETA and ETB receptors). Human big ET-3(1-41) is inactive on both vessels. Furthermore, phosphoramidon attenuated human big ET-1-induced contractions only in the umbilical artery and not in the vein. Such observations, in terms of substrate selectivity and phosphoramidon sensitivity, suggest the presence of distinct ECE activities in human vein and arteries.
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Affiliation(s)
- A Rizzi
- Department of Experimental and Clinical Medicine, University of Ferrara, Italy
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23
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Maguire JJ, Johnson CM, Mockridge JW, Davenport AP. Endothelin converting enzyme (ECE) activity in human vascular smooth muscle. Br J Pharmacol 1997; 122:1647-54. [PMID: 9422810 PMCID: PMC1565120 DOI: 10.1038/sj.bjp.0701564] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
1. We have characterized the human smooth muscle endothelin converting enzyme (ECE) present in the media of the endothelium-denuded human umbilical vein preparation. 2. Endothelin-1 (ET-1) and ET-2 were potent constrictors of umbilical vein with EC50 values of 9.2 nM and 29.6 nM, respectively. ET-1 was at least 30 times more potent than ET-3 suggesting the presence of constrictor ETA receptors. Little or no response was obtained to the ETB-selective agonist sarafotoxin 6c. These data suggest that endothelin-mediated vasoconstriction is via ETA receptors in this preparation. 3. Autoradiographical visualization of endothelin receptors with subtype selective ligands confirmed the predominance of the ETA receptor in the media of umbilical vein. High density of binding was obtained with the ETA selective [125I]-PD151242, with much lower levels detected with the ETB selective [125I]-BQ3020. 4. Big ET-1 (EC50 = 42.7 nM) and big ET-2(1-38) (EC50 = 99.0 nM) were less potent than ET-1 and ET-2, respectively. Big ET-2(1-38) was more potent than its isoform big ET-2(1-37) with concentration-response curves to big ET-2(1-37) incomplete at 300 nM. No response was obtained to big ET-3 at concentrations up to 700 nM. The C-terminal fragments, big ET-1(22-38) and big ET-2(22-38) were inactive. 5. Responses to ET-1 were unaffected by either the neutral endopeptidase (NEP) inhibitor thiorphan (10(-5) M) or by the dual NEP/ECE inhibitor phosphoramidon (10(-5) M). Big ET-1 was also unaffected by thiorphan but antagonized in a concentration-dependent manner by phosphoramidon (10(-5) M and 10(-4) M). 6. Addition of all four big endothelin peptides to human umbilical vein preparations resulted in detectable amounts of ET-IR in the bathing medium. Therefore, although big ET-3 was functionally inactive this reflects the low potency of ET-3 at the ETA receptor rather than the lack of ability of this smooth muscle ECE to convert big ET-3 to ET-3. 7. To conclude we have demonstrated the presence of a phosphoramidon-sensitive ECE on the smooth muscle layer of the human umbilical vein which can convert big ET-1, big ET-2(1-37), big ET-2(1-38) and big ET-3 to their mature biologically active forms. The precise subcellular localization of this enzyme and its physiological relevance remains to be determined.
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Affiliation(s)
- J J Maguire
- Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital
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