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Hitzerd E, Broekhuizen M, Neuman RI, Colafella KMM, Merkus D, Schoenmakers S, Simons SHP, Reiss IKM, Danser AHJ. Human Placental Vascular Reactivity in Health and Disease: Implications for the Treatment of Pre-eclampsia. Curr Pharm Des 2020; 25:505-527. [PMID: 30950346 DOI: 10.2174/1381612825666190405145228] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 03/29/2019] [Indexed: 12/17/2022]
Abstract
Adequate development of the placenta is essential for optimal pregnancy outcome. Pre-eclampsia (PE) is increasingly recognized to be a consequence of placental dysfunction and can cause serious maternal and fetal complications during pregnancy. Furthermore, PE increases the risk of neonatal problems and has been shown to be a risk factor for cardiovascular disease of the mother later in life. Currently, there is no adequate treatment for PE, mainly because its multifactorial pathophysiology remains incompletely understood. It originates in early pregnancy with abnormal placentation and involves a cascade of dysregulated systems in the placental vasculature. To investigate therapeutic strategies it is essential to understand the regulation of vascular reactivity and remodeling of blood vessels in the placenta. Techniques using human tissue such as the ex vivo placental perfusion model provide insight in the vasoactive profile of the placenta, and are essential to study the effects of drugs on the fetal vasculature. This approach highlights the different pathways that are involved in the vascular regulation of the human placenta, changes that occur during PE and the importance of focusing on restoring these dysfunctional systems when studying treatment strategies for PE.
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Affiliation(s)
- Emilie Hitzerd
- Department of Pediatrics, Division of Neonatology, Erasmus MC University Medical Center, Rotterdam, Netherlands.,Department of Internal Medicine; Division of Pharmacology and Vascular Medicine, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Michelle Broekhuizen
- Department of Pediatrics, Division of Neonatology, Erasmus MC University Medical Center, Rotterdam, Netherlands.,Department of Internal Medicine; Division of Pharmacology and Vascular Medicine, Erasmus MC University Medical Center, Rotterdam, Netherlands.,Department of Cardiology; Division of Experimental Cardiology, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Rugina I Neuman
- Department of Internal Medicine; Division of Pharmacology and Vascular Medicine, Erasmus MC University Medical Center, Rotterdam, Netherlands.,Department of Gynecology and Obstetrics, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Katrina M Mirabito Colafella
- Department of Internal Medicine; Division of Pharmacology and Vascular Medicine, Erasmus MC University Medical Center, Rotterdam, Netherlands.,Cardiovascular Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia.,Department of Physiology, Monash University, Melbourne, Australia
| | - Daphne Merkus
- Department of Cardiology; Division of Experimental Cardiology, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Sam Schoenmakers
- Department of Gynecology and Obstetrics, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Sinno H P Simons
- Department of Pediatrics, Division of Neonatology, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Irwin K M Reiss
- Department of Pediatrics, Division of Neonatology, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - A H Jan Danser
- Department of Internal Medicine; Division of Pharmacology and Vascular Medicine, Erasmus MC University Medical Center, Rotterdam, Netherlands
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Haugen G, Hovig T. Studies of autacoid responsiveness and endothelium dependency in human umbilical arteries. Scandinavian Journal of Clinical and Laboratory Investigation 2009; 52:141-9. [PMID: 1357738 DOI: 10.3109/00365519209088778] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The effect of serotonin, prostaglandin E2 (PGE2) and PGF2 alpha on the smooth muscle tension in perfused human umbilical arteries was investigated before and after removal of the endothelium. Denudation was performed mechanically using a nylon filament loop, and the efficiency of the procedure was checked by electron microscopy. In non-denuded vessels the autacoids elicited biphasic pressure responses, all starting with a vasodilatation and followed by a strong vasoconstriction. After denudation no dilatatory responses were evoked, whereas the constrictory responses appeared to be unchanged. Pre-treatment of the vessels with methylene blue did not affect the autacoid responses. Generally the perfusion pressure decreased after the de-endothelialization, in some preparations to levels of about 50% of the initial perfusion pressure. In about one-third of the preparations exposure to methylene blue led to a definite pressure increase. The results indicate that endothelium-derived factors are involved in the autacoid responses and also in the maintenance of basic vascular tonus in the umbilical circulation.
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Affiliation(s)
- G Haugen
- Department of Obstetrics and Gynecology, National Hospital, University of Oslo, Norway
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3
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Breslin EM, Teoh TG, Docherty JR. Investigations of Vascular Responses of Human Umbilical Vessels from Normal and Preeclamptic Pregnancies. Hypertens Pregnancy 2009. [DOI: 10.3109/10641959309042865] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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4
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Biarent D, Hubloue I, Bejjani G, Mélot C, Jespers P, Naeije R, Leeman M. Role of endothelins and nitric oxide in the pulmonary circulation of perinatal lambs during hyperoxia and hypoxia. Pediatr Res 2006; 59:131-6. [PMID: 16327012 DOI: 10.1203/01.pdr.0000191138.34387.e2] [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: 11/06/2022]
Abstract
Endothelins (ET) have opposite vascular effects mediated through different receptors: ET(A) receptors mediating vasoconstriction and ET(B) receptors mediating vasoconstriction as well as vasodilation. The role of ET in acute hypoxic pulmonary vasoconstriction (HPV) was studied after dual ET receptor blockade with bosentan and nitric oxide (NO) synthase inhibition with nitro-L-arginine (L-NA). We started from the hypothesis that ET antagonism may inhibit HPV but, if not, would do so after NO synthase inhibition. HPV was evaluated in anesthetized lambs, with an intact pulmonary circulation, by the increase in the mean pulmonary artery pressure (Ppa) minus occluded Ppa (Ppao) gradient in response to hypoxia (inspiratory oxygen fraction of 0.1) at different levels of pulmonary flow (multipoint pressure/flow relationships). ET receptor antagonism decreased pulmonary and systemic vascular tone both in hyperoxia and hypoxia. ET antagonism had no effect on HPV. NO synthase inhibition increased pulmonary vascular tone more in hypoxia than in hyperoxia so that HPV was enhanced. After L-NA, bosentan still decreased pulmonary vascular tone in hypoxia but did not affect the magnitude of HPV. The present results suggest that ET and NO are involved in the regulation of basal pulmonary vascular tone. Furthermore, the vasodilator effect of bosentan persisted in the presence of NO synthase inhibition, suggesting a non NO-dependent vasodilator mechanism. The results from these experiments are in agreement with the idea that ET do not play a major role in HPV in the perinatal lamb, even when it is enhanced by NO synthase inhibition.
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Affiliation(s)
- Dominique Biarent
- Laboratory of Physiology, Faculty of Medicine, Erasme Campus of the Free University of Brussels, Belgium.
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5
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Naidoo V, Naidoo S, Raidoo DM. Immunolocalisation of endothelin-1 in human brain. J Chem Neuroanat 2004; 27:193-200. [PMID: 15183204 DOI: 10.1016/j.jchemneu.2004.03.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2003] [Revised: 11/25/2003] [Accepted: 03/05/2004] [Indexed: 10/26/2022]
Abstract
The potent vasoconstrictor endothelin-1 (ET-1) may function as a neuropeptide and be a contributing factor in some neurological disorders, e.g. Alzheimer's dementia. The presence of ET-1 has been studied more extensively in the rat and porcine nervous systems than in the human brain. Also, the recent description of the extensive ET-1 mRNA localisation in human neural tissue supports expression in regions of human brain not previously investigated. Using specific anti-ET-1 polyclonal antiserum, we immunolocalised ET-1 in 24 regions of human brain autopsy tissues, and correlated this with ET-1 mRNA distribution. ET-1 immunoreactivity was observed within some cells of all the 24 areas examined. Neuronal staining for ET-1 was demonstrated within the diencephalon, brainstem, basal nuclei, cerebral cortex, cerebellar hemisphere, amygdala and hippocampus. In addition, ET-1 immunolabelling was visualised in the pituitary gland as well as in the choroid plexus. The primary sensory cortex and pineal gland also contained immunoreactive ET-1, although ET-1 mRNA had never been detected in these regions previously. The localisation of ET-1 and its subsequent correlation with ET-1 mRNA in most of the regions investigated suggest a more extensive distribution of the ET system in the human brain than was previously identified.
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Affiliation(s)
- V Naidoo
- Department of Pharmacology, Nelson R Mandela School of Medicine, University of Natal, South Africa
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6
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Lang I, Pabst MA, Hiden U, Blaschitz A, Dohr G, Hahn T, Desoye G. Heterogeneity of microvascular endothelial cells isolated from human term placenta and macrovascular umbilical vein endothelial cells. Eur J Cell Biol 2003; 82:163-73. [PMID: 12751902 DOI: 10.1078/0171-9335-00306] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The present study compares some phenotypic and physiologic characteristics of microvascular and macrovascular endothelial cells from within one human organ. To this end microvascular endothelial cells from human full-term placenta (PLEC) were isolated using a new method and compared with macrovascular human umbilical vein endothelial cells (HUVEC) and an SV40-transformed placental venous endothelial cell line (HPEC-A2). PLEC were isolated by enzymatic perfusion of small placental vessels, purified on a density gradient and cultured subsequently. Histological sections of the enzyme-treated vessels showed a selective removal of the endothelial lining in the perfused placental cotyledons. The endothelial identity of the cells was confirmed by staining with the endothelial markers anti-von Willebrand factor, Ulex europaeus lectin and anti-QBEND10. The cells internalized acetylated low-density lipoprotein and did not show immunoreactivity with markers for macrophages, smooth muscle cells and fibroblasts. The spindle-shaped PLEC grew in swirling patterns similar to that described for venous placental endothelial cells. However, scanning electron microscopic examination clearly showed that PLEC remained elongated at the confluent state, in contrast to the more polygonal phenotype of HPEC-A2 and HUVEC that were studied in parallel. The amount of vasoactive substances (endothelin-1,2, thromboxane, angiotensin II, prostacyclin) released into the culture medium and the proliferative response to cytokines was more similar to human dermal microvessels (MIEC) derived from non-fetal tissue than to HUVEC. Potent mitogens such as vascular endothelial growth factors (VEGF121, VEGF165) and basic fibroblast growth factor (FGF-2) induced proliferation of all endothelial cell types. Placental growth factors PIGF-1 and PIGF-2 effectively stimulated cell proliferation on PLEC (142 +/- 7% and 173 +/- 10%) and MIEC (160 +/- 20% and 143 +/- 28%) in contrast to HUVEC (9 +/- 8% and 15 +/- 20%) and HPEC-A2 (15 +/- 7% and 24 +/- 6%) after 48 h incubation time under serum-free conditions. These data support evidence for (1) the microvascular identity of the isolated PLEC described in this study, and (2) the phenotypic and physiologic heterogeneity of micro- and macrovascular endothelial cells within one human organ.
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Affiliation(s)
- Ingrid Lang
- Institute of Histology and Embryology, University of Graz, Graz, Austria.
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7
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Jankov RP, Luo X, Cabacungan J, Belcastro R, Frndova H, Lye SJ, Tanswell AK. Endothelin-1 and O2-mediated pulmonary hypertension in neonatal rats: a role for products of lipid peroxidation. Pediatr Res 2000; 48:289-98. [PMID: 10960492 DOI: 10.1203/00006450-200009000-00005] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We hypothesized that reactive O2 species, or their intermediary products, generated during exposure to elevated O2 lead to pathologic endothelin-1 expression in the newborn lung. Endothelin-1 expression and 8-isoprostane content (an in vivo marker of lipid peroxidation) were examined and found to be elevated (p < 0.05) in the lungs of newborn rats with abnormal lung morphology and pulmonary hypertension, as assessed by right ventricular hypertrophy, after a 14-d exposure to 60% O2. The antioxidant and lipid hydroperoxide scavenger, U74389G (10 mg/kg), given by daily i.p. injection prevented O2-dependent right ventricular hypertrophy (p < 0.05 compared with vehicle-treated controls), but had no effect on abnormal lung morphology. Additionally, we observed that 8-isoprostane caused marked endothelin-1 mRNA up-regulation in vitro in primary rat fetal lung cell cultures. We conclude that reactive O2 species, or their bioactive intermediaries, are causative in O2-mediated pulmonary hypertension and endothelin-1 up-regulation. It is likely that the bioactive lipid peroxidation product, 8-isoprostane, plays a key role in pathologic endothelin-1 expression and pulmonary hypertension during oxidant stress.
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Affiliation(s)
- R P Jankov
- Medical Research Council Group in Lung Development and Lung Biology Programme, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
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Kim HS, Hwang KK, Seo JW, Kim SY, Oh BH, Lee MM, Park YB. Apoptosis and regulation of Bax and Bcl-X proteins during human neonatal vascular remodeling. Arterioscler Thromb Vasc Biol 2000; 20:957-63. [PMID: 10764659 DOI: 10.1161/01.atv.20.4.957] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To verify that apoptosis is one of the possible mechanisms of neonatal vascular remodeling during the transition from fetal to neonatal circulation, we assayed for apoptosis and evaluated the expression of apoptosis-regulatory proteins in umbilical vessel versus ascending aorta, ductus arteriosus (DA) versus adjacent pulmonary artery and aorta, or aorta versus its branching arteries. Twenty-two umbilical cords (UCs), 6 DAs with adjacent aortas and pulmonary arteries, and 4 aortic arches with their branching great arteries were obtained from neonates. Smooth muscle cell (SMC) apoptosis in umbilical vessels was identified in all UCs. The expressions of Bax and Bcl-X were stronger in umbilical artery than in the neonatal aorta, but Bcl-2 was weak in both arteries in immunohistochemistry. In the immunoblot analysis of UCs, the expression of the proapoptotic short isoform of Bcl-X was stronger than in other tissue, and caspase-3 was selectively activated, whereas it was not in the other components of the cardiovascular system. In contrast, the expression patterns of the FasAg and Fas ligand were similar in umbilical artery and aorta. Regulation of Bcl-2 family proteins was also observed in other vascular sites at which SMCs undergo apoptosis on hemodynamic changes during birth, such as the DA and the branching points of the great arteries from the aortic arch. Apoptosis is involved in the regression of human umbilical vessels and the DA and in the remodeling of the branching great arteries during the neonatal period, when Bcl-2 family proteins are likely to play a key role.
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Affiliation(s)
- H S Kim
- Heart Research Institute, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
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9
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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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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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Green LR, McGarrigle HH, Bennet L, Hanson MA. The role of endothelin-A receptors in cardiovascular responses to acute hypoxaemia in the late gestation sheep fetus. J Physiol 1998; 509 ( Pt 1):297-304. [PMID: 9547402 PMCID: PMC2230950 DOI: 10.1111/j.1469-7793.1998.297bo.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
1. In unanaesthetized chronically instumented fetal sheep (118-121 days gestation) we investigated the effect of acute isocapnic hypoxaemia (arterial Po2, 12.5 +/- 0.6 mmHg) on heart rate (FHR), mean systemic arterial blood pressure (MABP), carotid and femoral blood flows (CBF and FBF, respectively), and carotid and femoral vascular resistances (CVR and FVR, respectively) with the infusion of either the endothelin-A (ETA) receptor antagonist FR139317, or saline vehicle. 2. During normoxaemia FHR (P < 0.05) and CBF (P < 0. 01) were greater, and CVR (P < 0.01) was lower with FR139317 than with vehicle infusion. CVR remained lower with FR139317 than with vehicle infusion during hypoxaemia (P < 0.01) and recovery (P < 0. 05). During hypoxaemia the rapid initial bradycardia, the increase in MABP and FVR and the decrease in FBF were similar with vehicle and FR139317 infusion. In both groups plasma endothelin-1 concentration ([ET-1]) was unaltered by hypoxaemia. The increase in CBF during hypoxaemia with vehicle (P < 0.01) was absent with FR139317 infusion. 3. Thus in the late gestation ovine fetus endogenous ET-1 modulates basal FHR, CBF and CVR via ETA receptors. Modulation of CBF and CVR persists during hypoxaemia but ETA receptors do not appear to contribute to the decrease in femoral blood flow measured during acute hypoxaemia.
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Affiliation(s)
- L R Green
- Department of Obstetrics & Gynaecology, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK.
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Grabau BJ, Gude NM, King RG, Riley SC, Brennecke SP. Endothelins-1, 2 and 3 are released in vitro from the human bilaterally perfused placenta. J Perinat Med 1997; 25:11-6. [PMID: 9085198 DOI: 10.1515/jpme.1997.25.1.11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Immunoreactive-endothelin (ir-ET) has previously been detected in human fetal effluents from in vitro perfused placentae. To date however, because of a lack of radio-immunoassay specificity, the ET isoforms in fetal effluents had not been determined, nor had placental maternal effluents been examined for ETs. The aim of this study was to identify the isoforms of ET released into the maternal and fetal circulations of the human in vitro bilaterally perfused placenta. Both circulations of placentae, obtained after normal vaginal delivery, were perfused with a modified Krebs solution and maternal and fetal effluents from the start of the second hour of perfusion were collected, extracted on Scp-pak C18 cartridges, concentrated by vacuum evaporation and separated by reverse-phase HPLC separation. HPLC fractions were measured by ET-RIA and compared to known synthetic standards. Maternal and fetal effluents contained ET-1 (natural and oxidised ET-1), ET-2 and ET-3 (n = 5). Maternal and fetal release of ET-1 was 2.2 +/- 0.7 and 1.4 +/- 0.1 fmol/min/g wet weight of tissue respectively, ET-2 was 0.4 +/- 0.2 and 0.5 +/- 0.2 and fmol/min/g respectively, and ET-3 was 0.5 +/- 0.2 and 0.7 +/- 0.4 fmol/min/g respectively. There were no significant differences between the release of either ET-1, ET-2 or ET-3 in the maternal or fetal circulations. In conclusion, this study indicated that ET-1, ET-2 and ET-3 were all released into both the maternal and fetal effluents from the in vitro perfused human placenta.
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Affiliation(s)
- B J Grabau
- Department of Perinatal Medicine, Royal Women's Hospital, Carlton, Victoria, Australia
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Bogoni G, Rizzi A, Calo G, Campobasso C, D'Orleans-Juste P, Regoli D. Characterization of endothelin receptors in the human umbilical artery and vein. Br J Pharmacol 1996; 119:1600-4. [PMID: 8982507 PMCID: PMC1915792 DOI: 10.1111/j.1476-5381.1996.tb16078.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The aim of the present study was to characterize pharmacologically endothelin receptors that are present in human umbilical vessels. 2. Endothelin-1 (ET-1) and endothelin-2 (ET-2) are potent stimulants of both the human umbilical artery (pEC50 7.9 and 7.5) and vein (pEC50 8.1 and 8.0). Endothelin-3 (ET-3) is inactive on the artery but contracts the vein (pEC50 7.6). IRL1620 is inactive in both vessels. The order of potency of agonists is suggestive of a typical ET(A) receptor in the artery (ET-1 = ET-2 > > ET-3) and a mixture of ET(A) and ET(B) receptors in the vein (ET-1 = ET-2 > or = ET-3). 3. The selective ET(A) receptor antagonist, BQ123, competitively inhibits the effect of ET-1 in the human umbilical artery (pA2 6.9), while in the vein, only a mixture of BQ123 and BQ788 (a selective ET(B) antagonist) weakly displaces to the right of the cumulative concentration-response curve to ET-1. Contractions induced by ET-3 in the vein are inhibited by BQ788 (pA2 7.6), but not by BQ123. 4. Inhibition of Ca2+ channels by nifedipine (0.1 microM) is accompanied by a significant decrease of the maximal response to ET-1 by 40% in the artery and by 30% in the vein. The response of the vein to ET-3 is almost abolished by nifedipine. 5. The results indicate that: (i) endothelins contract the human isolated umbilical artery via stimulation of an ET(A) receptor type; (ii) the contraction induced by ET-1 in the vein is mediated by both ET(A) and ET(B) receptors, while ET-3 stimulates the ET(B) receptor; (iii) the contribution of Ca2+ channels to the contraction mediated by the ET(B) receptor appears to be more important than to that mediated by the ET(A) receptor.
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Affiliation(s)
- G Bogoni
- Institute of Pharmacology, University of Ferrara, Italy
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Bogaert GA, Kogan BA, Mevorach RA, Wong J, Gluckman GR, Fineman JR, Heymann MA. Exogenous endothelin-1 causes renal vasodilation in the fetal lamb. J Urol 1996; 156:847-53. [PMID: 8683799 DOI: 10.1097/00005392-199608001-00085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE Endothelin-1 is known to be a potent vasoconstrictor. We investigated the effects and mechanisms of action of endothelin-1 and its receptors in regulating renal vascular tone in the fetal lamb. MATERIALS AND METHODS We observed the in vivo effects of endothelin-1, an endothelin-b receptor agonist (4-alanine-endothelin-1), endothelin-a receptor antagonists (BQ-610 and BQ-123), and the inhibition of prostaglandin and nitric oxide synthesis on the response of the renal circulation to endothelin-1 in a chronic preparation in third trimester fetal lambs. RESULTS After injection of 250 ng./kg. endothelin-1 into the descending aorta proximal to the renal arteries in 8 fetal animals, renal blood flow increased (4.4 +/- 0.7 ml. per minute per kg., p < 0.001 versus vehicle), as did mean arterial blood pressure (3.0 +/- 0.3 mm. Hg,p < 0.001 versus vehicle). Calculated renal vascular resistance decreased (-1.1 +/- 0.2 mm. Hg per minute per kg./ml., p < 0.001 versus vehicle). After injection of 1,725 ng./kg. 4-alanine-endothelin-1 in 5 animals renal blood flow increased (3.8 +/- 0.4 ml. per minute per kg., p < 0.05 versus vehicle) and mean arterial blood pressure was unchanged (1.6 +/- 1.7 mm. Hg). Calculated renal vascular resistance decreased (-0.8 +/- 0.2 mm. Hg per minute per kg./ml., p < 0.05 versus vehicle). After injection of 0.5 mg./kg. BQ-610 in 6 animals renal blood flow increased (2.3 +/- 0.7 ml. per minute per kg., p < 0.05) and mean arterial blood pressure decreased (-2.7 +/- 0.3 mm. Hg, p < 0.05 versus vehicle). Calculated renal vascular resistance decreased but this difference was not statistically significant (-0.7 +/- 0.3 mm. Hg per minute per kg./ml., p < 0.07). A dose of 1 mg./kg. BQ-123 in 2 animals decreased renal vascular resistance markedly. Infusion of a prostaglandin synthesis inhibitor (1 mg./kg. per minute meclofenamic acid) did not alter the decrease in renal vascular resistance after endothelin-1 (-0.7 +/- 0.4 mm. Hg per minute per kg./ml). In contrast, during infusion of a nitric oxide synthesis inhibitor (1.5 mg./kg. per minute N-omega-nitro-L-arginine) endothelin-1 increased renal vascular resistance (1.2 +/- 0.2 mm. Hg per minute per kg./ml., p < 0.001). CONCLUSIONS Endothelin-1 is a vasodilator in the fetal renal circulation, which acts primarily via endothelin-b receptors. Ongoing activity of endothelin-a receptors contributes to renal vascular tone in fetal lambs. The vasodilatory effects of endothelin-1 in the fetal lamb renal circulation are mediated via the nitric oxide system and not via prostanoids.
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Affiliation(s)
- G A Bogaert
- Department of Urology, University of California School of Medicine, San Francisco 94143-0738, USA
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15
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16
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Harvey-Wilkes KB, Nielsen HC, D'Alton ME. Elevated endothelin levels are associated with increased placental resistance. Am J Obstet Gynecol 1996; 174:1599-604. [PMID: 9065136 DOI: 10.1016/s0002-9378(96)70613-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The purpose of this study was to measure cord blood endothelin-1,2 concentrations in growth-restricted infants with abnormal flow velocity waveforms. STUDY DESIGN Endothelin-1,2 concentrations were measured by radioimmunoassay in the cord blood of 16 growth-restricted infants with abnormal flow velocity waveforms before delivery, 16 growth-restricted infants with normal flow velocity waveforms before delivery, and 44 appropriately grown infants. Clinical data regarding pregnancy complications and neonatal outcome were collected. RESULTS The mean endothelin-1,2 concentration in growth-restricted infants with abnormal flow velocity waveforms (50.2 +/- 16.4 pg/ml) was significantly higher than in growth-restricted infants with normal flow velocity waveforms (33.3 +/- 14.2 pg/ml, p < 0.05) or in appropriately grown infants (25.8 +/- 9.7 pg/ml, p < 0.05). Oligohydramnios was also associated with elevated endothelin levels. CONCLUSION We conclude that endothelin-1,2 concentrations are elevated in growth-restricted infants with abnormal flow velocity waveforms and may play a role in the development of abnormal fetoplacental resistance.
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Affiliation(s)
- K B Harvey-Wilkes
- Department of Pediatrics, Floating Hospital for Children, Boston, MA 02111, USA
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17
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Kakugawa Y, Giaid A, Yanagisawa M, Baynash AG, Melnyk P, Rosenberg L, Duguid WP. Expression of endothelin-1 in pancreatic tissue of patients with chronic pancreatitis. J Pathol 1996; 178:78-83. [PMID: 8778321 DOI: 10.1002/(sici)1096-9896(199601)178:1<78::aid-path423>3.0.co;2-n] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Chronic pancreatitis is characterized by the presence of an inflammatory infiltrate, progressive destruction of acinar cells, and fibrosis. The finding that endothelin-1, an endothelium-derived peptide with vasoconstrictive and mitogenic properties, reduces pancreatic blood flow in normal rats suggested that the peptide may be associated with the reduced pancreatic flow seen in animal models of chronic pancreatitis and in the morphological abnormalities of the disease. The aim of this study was to investigate sites of endothelin-1 expression in the pancreas of normal subjects and patients with chronic pancreatitis. The techniques of immunohistochemistry, in situ hybridization, and Northern blotting were used. Endothelin-1-like immunoreactivity was localized predominantly to islet cells both in normal subjects and in patients with chronic pancreatitis. Semi-quantitative analyses of immunostaining showed that endothelin-1-like immunoreactivity in islet cells of patients with chronic pancreatitis was greater than in normal subjects. Co-localization studies with glucagon, insulin, somatostatin, and pancreatic polypeptide showed that endothelin-1-like immunoreactivity co-exists with glucagon and insulin. There was no apparent co-existence of endothelin-1-like immunoreactivity with somatostatin or pancreatic polypeptide. Endothelin-1 mRNA was expressed in sites similar to those of the immunostaining, as well as in vascular endothelial cells. Northern blot analysis showed an increase in the expression of endothelin-1 mRNA in the patient population. There was a significant correlation between intensity of endothelin-1 immunostaining and severity of fibrosis in the patients with chronic pancreatitis. These findings suggest that an elevation in local expression of endothelin-1 may be associated with the morphological and haemodynamic changes of chronic pancreatitis.
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Affiliation(s)
- Y Kakugawa
- Department of Pathology, Montreal General Hospital and McGill University, Quebec, Canada
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18
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Liu YA, Ostlund E, Fried G. Endothelin-induced contractions in human placental blood vessels are enhanced in intrauterine growth retardation, and modulated by agents that regulate levels of intracellular calcium. ACTA PHYSIOLOGICA SCANDINAVICA 1995; 155:405-14. [PMID: 8719260 DOI: 10.1111/j.1748-1716.1995.tb09990.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Endothelin-1 (ET-1) is a strongly vasoactive polypeptide that may be involved in the regulation of the uteroplacental blood flow. In the present study we have examined the contractile response to ET-1 in human placental arteries in the presence of several agents that interfere with storage of intracellular calcium, e.g. caffeine, ryanodine and thapsigargin. We have also compared the contractile response to ET-1 in normal pregnancies with that of patients with foetal intrauterine growth retardation (IUGR), a condition with reduced uteroplacental blood flow. We found that the response to ET-1 in the placental arteries from women with normal pregnancies was reduced by 20% in the absence of extracellular calcium. Caffeine relaxed the basal tone of the vessels and reduced the contractile response to ET-1 by 51%. Nifedipine in addition to caffeine resulted in a reduction of 70%. Ryanodine also reduced the tone. Thapsigargin had no effect on the placental arteries at lower concentrations, but gave a progressive and slow contraction at 10(-6) M. The ET-1 induced contraction in placental arteries from IUGR patients was 67% more potent than in placental arteries from women with normal pregnancies, 129% as compared with 77% of the maximal K(+)-induced contraction. We conclude that the ET-1-induced contractile response in the human placental artery is dependent on influx of extracellular calcium as well as mobilization of calcium from intracellular stores. An increased sensitivity to ET-1 in placental arteries may contribute to the reduced uteroplacental blood flow in intrauterine growth retardation.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Adult
- Arteries/drug effects
- Caffeine/pharmacology
- Calcium/metabolism
- Calcium Channel Agonists/pharmacology
- Calcium Channel Blockers/pharmacology
- Calcium-Transporting ATPases/antagonists & inhibitors
- Endothelins/pharmacology
- Enzyme Inhibitors/pharmacology
- Female
- Fetal Growth Retardation/physiopathology
- Humans
- In Vitro Techniques
- Muscle Contraction/drug effects
- Muscle Relaxation/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Nifedipine/pharmacology
- Phosphodiesterase Inhibitors/pharmacology
- Placental Circulation/physiology
- Pregnancy
- Ryanodine/pharmacology
- Terpenes/pharmacology
- Thapsigargin
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Affiliation(s)
- Y A Liu
- Department of Women and Child Health, Karolinska Institute and Hospital, Stockholm, Sweden
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19
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Abstract
Endothelins and atrial natriuretic peptide (ANP) are vasoactive peptides with effects on the human uterine and umbilical arteries. Endothelin (ET) contracts the vascular smooth muscle. Both ETA- and non-ETA-non-ETB-receptors seem to be involved. Autoradiography reveals binding of ET to vascular smooth muscle. ANP counteracts the contractile effects of angiotensin II in the human uterine artery. Head-down tilt results in elevation of plasma ANP in healthy pregnant women, while the same manoeuvre induces down-regulation of the reninangiotensin-aldosterone system in non-pregnant women and patients suffering from pre-eclampsia.
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Affiliation(s)
- M Stjernquist
- Department of Obstetrics and Gynecology at Malmö, University of Lund, Sweden
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20
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Bodelsson G, Marsál K, Stjernquist M. Reduced contractile effect of endothelin-1 and noradrenalin in human umbilical artery from pregnancies with abnormal umbilical artery flow velocity waveforms. Early Hum Dev 1995; 42:15-28. [PMID: 7545576 DOI: 10.1016/0378-3782(95)01636-h] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This study on the human umbilical artery was undertaken in order to elucidate possible correlations between changes in response to vasoactive substances in vitro and abnormal umbilical artery flow velocity waveforms in vivo associated with preeclampsia and intrauterine growth retardation. The vascular reactivity to endothelin-1, noradrenalin, serotonin, the thromboxane A2 analogue U46619, substance P and prostacyclin was determined in umbilical artery segments from 13 normal pregnancies and 29 pregnancies complicated with preeclampsia and/or intrauterine growth retardation with normal or abnormal umbilical flow velocity waveforms. The contractile effect in vitro of endothelin-1 and noradrenalin was reduced in segments from pregnancies complicated by abnormal umbilical flow velocity waveforms in vivo. No differences were detected in the contractile effect of serotonin and U46619, or in the relaxatory effect of substance P and prostacyclin. In conclusion, endothelin-1- and noradrenalin-related mechanisms could be involved in the abnormal umbilical flow velocity waveforms associated with preeclampsia and intrauterine growth retardation.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
- Adult
- Blood Flow Velocity/drug effects
- Blood Flow Velocity/physiology
- Dose-Response Relationship, Drug
- Endothelins/pharmacology
- Epoprostenol/pharmacology
- Female
- Fetal Growth Retardation/physiopathology
- Hemodynamics/drug effects
- Hemodynamics/physiology
- Humans
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Norepinephrine/pharmacology
- Pre-Eclampsia/physiopathology
- Pregnancy
- Prostaglandin Endoperoxides, Synthetic/pharmacology
- Regional Blood Flow/drug effects
- Regional Blood Flow/physiology
- Serotonin/pharmacology
- Substance P/pharmacology
- Thromboxane A2/analogs & derivatives
- Thromboxane A2/pharmacology
- Ultrasonography, Doppler
- Umbilical Arteries/physiology
- Vasoconstriction/drug effects
- Vasoconstriction/physiology
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- G Bodelsson
- Department of Obstetrics and Gynecology, University Hospital, Malmö, Sweden
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21
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22
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Poston L, McCarthy AL, Ritter JM. Control of vascular resistance in the maternal and feto-placental arterial beds. Pharmacol Ther 1995; 65:215-39. [PMID: 7792316 DOI: 10.1016/0163-7258(94)00064-a] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This review aims to provide a comprehensive summary of the mechanisms involved in the physiological adaptation of the vasculature to pregnancy. Profound changes occur both systemically and in discrete circulations in the mother, but it is debatable which factors are responsible. Similarly, whilst the feto-placental circulation must be substantially controlled by humoral mechanisms, the exact role of each potential contributor is not known. In view of the hitherto unappreciated and very important role of the endothelium-derived vasodilator, nitric oxide, in the control of peripheral vascular resistance, considerable emphasis will be placed on the many recent investigations in this area.
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Affiliation(s)
- L Poston
- UMDS Smooth Muscle Group, United Medical and Dental School, Guy's Hospital, London, U.K
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23
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Rae GA, Calixto JB, D'Orléans-Juste P. Effects and mechanisms of action of endothelins on non-vascular smooth muscle of the respiratory, gastrointestinal and urogenital tracts. REGULATORY PEPTIDES 1995; 55:1-46. [PMID: 7724825 DOI: 10.1016/0167-0115(94)00098-i] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- G A Rae
- Department of Pharmacology, Universidade Federal de Santa Catarina, Florianópolis, Brazil
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24
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McGowan FX, Davis PJ, Siewers RD, del Nido PJ. Coronary vasoconstriction mediated by endothelin-1 in neonates. Reversal by nitroglycerin. J Thorac Cardiovasc Surg 1995; 109:88-97; discussion 97-8. [PMID: 7815811 DOI: 10.1016/s0022-5223(95)70424-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To determine the role of the vasoconstrictor peptide endothelin-1 in cardiopulmonary bypass in neonates, we measured plasma endothelin-1 concentrations in infants before and after cardiopulmonary bypass for arterial switch procedures and studied the effects of endothelin-1 on coronary tone and contractility in normal and reperfused neonatal pig hearts. Endothelin-1 blood concentrations (picograms per milliliter, mean +/- standard error) were significantly higher in neonates with arterial transposition and in umbilical venous blood (22.9 +/- 2.3 and 19.2 +/- 2.9, respectively) than in older children with atrial septal defects (13.2 +/- 1.6) or in healthy adults (10.7 +/- 2.5). After cardiopulmonary bypass, endothelin-1 concentrations increased 29% in neonates undergoing arterial switch procedure and 28% in children undergoing atrial septal defect repair (p < 0.05 versus before bypass). In isolated, blood-perfused neonatal pig hearts, endothelin-1 had dose-related coronary constrictor and inotropic effects between 25 and 100 pmol. Endothelin-1 concentrations that did not increase coronary perfusion pressure (5 to 10 pmol) caused significant coronary constriction in the presence of norepinephrine (10 nmol/L). During reperfusion after 30 minutes of global normothermic ischemia, the coronary vasoconstrictor effects of both endothelin-1 alone and endothelin-1 plus norepinephrine were significantly enhanced. Nitroglycerin reversed vasoconstriction produced by endothelin-1 and endothelin-1 plus norepinephrine both before and after ischemia-reperfusion. We conclude that endothelin-1 concentrations are significantly elevated in neonates and are further increased after cardiopulmonary bypass. Coronary vasoconstriction caused by endothelin-1 is enhanced by ischemia-reperfusion and by norepinephrine present in concentrations typically observed after neonatal cardiopulmonary bypass. Nitroglycerin reverses coronary vasoconstriction induced by endothelin-1 and may therefore be beneficial in the postoperative management of neonates after cardiac operations.
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Affiliation(s)
- F X McGowan
- Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh School of Medicine, Pa
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25
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Radunovic N, Lockwood CJ, Alvarez M, Nastic D, Petkovic S, Berkowitz RL. Fetal and maternal plasma endothelin levels during the second half of pregnancy. Am J Obstet Gynecol 1995; 172:28-32. [PMID: 7847556 DOI: 10.1016/0002-9378(95)90079-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Our objective was to evaluate maternal and fetal endothelin concentrations in uncomplicated pregnancies across the second half of pregnancy. STUDY DESIGN Paired (n = 64) maternal venous and fetal umbilical venous or arterial samples were obtained during cordocentesis. In addition, eight neonatal umbilical vein samples were obtained immediately after delivery. Samples were assessed for hematocrit and pH, and concentrations of endothelin were measured by sensitive enzyme immunoassay. RESULTS No significant correlation was found between either fetal or maternal endothelin levels and gestational age (r = 0.01, p = 0.91 and r = 0.07, p = 0.5, respectively). Fetal plasma endothelin concentrations were significantly lower than neonatal umbilical vein endothelin levels [median 2.5 pg/ml (range 0.9 to 5.73) vs 15.77 pg/ml (8.12 to 19.58), respectively; p < 0.0001] but significantly higher than maternal levels [1.3 pg/ml (0.8 to 3.25); p < 0.0001]. In addition, endothelin values were higher in the umbilical artery than in the umbilical vein, but this difference failed to achieve statistical significance [2.89 pg/ml (1.61 to 5.73) vs 2.29 pg/ml (0.9 to 5.70), respectively; p = 0.06]. No correlation was noted between fetal and maternal endothelin levels (r = 0.12, p = 0.36). CONCLUSION Fetal endothelin levels were significantly higher than maternal levels, but neither correlated with gestational age across the second half of pregnancy.
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Affiliation(s)
- N Radunovic
- Department of Obstetrics, Gynecology and Reproductive Science, Mount Sinai School of Medicine, New York, NY 10029-6574
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26
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Malamitsi-Puchner A, Antsaklis A, Economou E, Mesogitis S, Papantoniou N, Koutra N, Aravantinos D. Endothelin 1-21 plasma levels in fetuses at 18-24 weeks of gestation. J Perinat Med 1995; 23:321-5. [PMID: 8537863 DOI: 10.1515/jpme.1995.23.4.321] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study aimed to establish normal endothelin (ET) ranges in non malformed appropriate for gestational age fetuses of 18-24 weeks gestation and to investigate a possible correlation between maternal and fetal ET plasma levels. Twenty "mother-fetus" pairs were included in the study. The determination of ET 1-21 was performed by radioimmunoassay using 1 ml of fetal blood obtained by cordocentesis--indicated for various reasons--and in 2 ml of maternal venous blood. The statistical analysis involved the Wilcoxon test for pair differences and the Spearman rank correlation coefficient. Fetal and maternal ET 1-21 levels were respectively 11.39 +/- 2.22 pmol/L and 6.44 +/- 1.00 pmol/L. Fetal levels were significantly higher (p < 0.01) thus excluding passive ET transfer through the placenta, while no correlation between maternal and fetal levels was found. It is speculated that high fetal ET 1-21 levels result from increased ET production, which possess cell proliferative properties and/or decreased ET removal from the fetal circulation because of hypofunctioning lungs and kidneys. It can be assumed that the increased amounts of fetal ETs contribute to normal growth and development directly as well as by regulating vascular tonus and local blood flow.
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Affiliation(s)
- A Malamitsi-Puchner
- Department of Feto-Maternal Medicine, 1st University Clinic for Obstetrics and Gynecology, Alexandra University and State Hospital, Athens, Greece
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27
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Fried G, Liu YA. Effects of endothelin, calcium channel blockade and EDRF inhibition on the contractility of human uteroplacental arteries. ACTA PHYSIOLOGICA SCANDINAVICA 1994; 151:477-84. [PMID: 7976421 DOI: 10.1111/j.1748-1716.1994.tb09770.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In order to examine the possibility that endothelin might be important in the regulation of placental blood flow, human uteroplacental vessels were superfused in vitro to study the contractile effect of endothelin as compared with a known strong contractor of placental blood vessels, serotonin (5-HT). The contractile responses were compared in the presence and absence of calcium channel blocking agents, as well as in the presence of L-NMA, an inhibitor of EDRF/nitric oxide. Endothelin (ET, 10(-10)-10(-6) M) and 5-HT (10(-8)-10(-4) M) induced contractions in the vessels. Maximal contractions in the presence of endothelin were elicited at 10(-7) M, whereas 5-HT elicited maximal contractions at 10(-5) M. At 10(-7) M, ET was more potent than 5-HT. The calcium-channel blocking agents nifedipine, diltiazem and NiCl2 relaxed the vessels by 5-15% from baseline. The contractile response to ET in the presence of nifedipine or diltiazem was reduced by 55 and 67%, respectively. The response of 5-HT in the presence of nifedipine was reduced by 58%. The contractile response to 5-HT as well as ET in the presence of both nifedipine and NiCl2 was not significantly lower than in the presence of nifedipine only. The EDRF-inhibiting agent L-NMA caused a small contractile response at concentrations of 10(-6)-10(-5) M. ET as well as 5-HT added after pretreatment with L-NMA produced a larger contractile response than ET or 5-HT alone. The results show that ET has a strong contractile effect on placental blood vessels at concentrations likely to occur during labor and delivery. The mechanism whereby ET as well as 5-HT contracts placental vessel smooth muscle appears to partly involve nifedipine- and diltiazem-sensitive calcium channels, but almost half of the response depends on mobilization of calcium through other means.
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Affiliation(s)
- G Fried
- Department of Obstetrics and Gynecology, Karolinska Institute, Stockholm, Sweden
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28
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Affiliation(s)
- K Stephenson
- Department of Biochemistry, University of Texas Health Science Center at San Antonio 78284
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29
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Semama DS, Thonney M, Guignard JP. Role of endogenous endothelin in renal haemodynamics of newborn rabbits. Pediatr Nephrol 1993; 7:886-90. [PMID: 8130126 DOI: 10.1007/bf01213379] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Endothelin is a potent vasoconstrictor peptide produced by vascular endothelial cells which could play a role in the physiological regulation of the renal microcirculation. To test this hypothesis, experiments were performed in 24 anaesthetized and mechanically-ventilated newborn rabbits. In 8 newborn rabbits (group 1), a bolus injection of 5 nmol/kg endothelin caused a marked increase in mean blood pressure (MBP) and renal vascular resistance (RVR), leading to a significant fall in glomerular filtration rate (GFR) (by 12% +/- 4%) and renal blood flow (RBF) by 16% +/- 3%). A second group of animals (n = 8) was used for testing the in vivo neutralizing activity of an endothelin-1 antiserum. The antiserum was thereafter infused into 8 additional newborn rabbits (group 3) in order to define the role of endogenous endothelin in modulating the function of the immature kidney. The antiserum induced a surprising increase in RVR (by 34% +/- 9%, P < 0.05) associated with a fall in GFR (by 21% +/- 4%, P < 0.05) and RBF (by 25% +/- 4%, P < 0.05), while the filtration fraction and MBP remained unchanged. The occurrence of a vasoconstrictive response to both high-dose endothelin and to its antiserum could be explained by the recent demonstration that high levels of endothelin lead to renal vasoconstriction, while lower levels induce renal vasodilatation. The present results suggest that endogenous endothelin is active at low levels under normal conditions and that this peptide plays a role in the physiological control of renal function, but not MBP.
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Affiliation(s)
- D S Semama
- Service de Pédiatrie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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30
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Sakamoto Y, Doi Y, Ohsato K, Fujimoto S. Immunoelectron microscopy on the localization of endothelin in the umbilical vein of perinatal rabbits. Anat Rec (Hoboken) 1993; 237:482-8. [PMID: 8311261 DOI: 10.1002/ar.1092370407] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Immunoelectron microscopic localization of endothelin (ET) using the mouse monoclonal anti-ET sera was performed on the pre- and postnatal rabbit umbilical vein during stages when Weibel-Palade (WP) bodies increase in number in the endothelial cells. The immunoreactions are localized in the rough endoplasmic reticulum, Golgi cisterns, and WP bodies that are actively segregated from the Golgi apparatus. After degranulation and extracellular release of WP bodies was induced by compound 48/80, heavy immunoreactions were seen in both vascular lumen and cytoplasm near the degranulated WP bodies. These results indicate that ET is stored in WP bodies after segregation from the Golgi apparatus and released from the endothelial cells concomitantly with other components of these granules by exocytosis. Because the immunoreactions are also seen in pinocytotic vesicles that are occasionally in contact with WP bodies, it seems likely that WP bodies are also involved in the uptake and storage of ET from blood plasma.
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Affiliation(s)
- Y Sakamoto
- Department of Surgery, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
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31
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Bodelsson G, Stjernquist M. Characterization of endothelin receptors and localization of 125I-endothelin-1 binding sites in human umbilical artery. Eur J Pharmacol 1993; 249:299-305. [PMID: 8287917 DOI: 10.1016/0014-2999(93)90526-n] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The mechanisms of endothelin-1-induced contractile response in the human umbilical artery were investigated in vitro. Autoradiography revealed 125I-endothelin-1 binding sites in the smooth muscle layer of the vessel wall. Endothelin-1 and sarafotoxin S6b induced concentration-dependent contractions while endothelin-3 was virtually without contractile effect. The endothelin ETA receptor antagonist BQ 123 did not affect the contraction to endothelin-1 but antagonized the contraction to sarafotoxin S6b. The contraction to endothelin-1 and sarafotoxin S6b was diminished by both verapamil and nicardipine. It can be concluded that endothelin-1 is a vasoconstrictor in the human umbilical artery, probably acting via more than one contraction-mediating receptor. The 125I-endothelin-1 binding sites demonstrated in the smooth muscle layer of the vessel may correspond to receptors mediating the contractile effect. The mechanisms of action seems to involve activation of Ca2+ channels. The present study does not give any evidence for interaction of endothelin-1 with other endothelium-derived vasoactive agents in this vessel.
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Affiliation(s)
- G Bodelsson
- Department of Obstetrics and Gynecology at Malmö, University of Lund, General Hospital, Sweden
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32
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Kim HS, Aikawa M, Kimura K, Kuro-o M, Nakahara K, Suzuki T, Katoh H, Okamoto E, Yazaki Y, Nagai R. Ductus arteriosus. Advanced differentiation of smooth muscle cells demonstrated by myosin heavy chain isoform expression in rabbits. Circulation 1993; 88:1804-10. [PMID: 8403325 DOI: 10.1161/01.cir.88.4.1804] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND The closure of the ductus arteriosus (DA) is one of the most striking cardiovascular events that occur at birth. It has been attributed to oxygenation and intrinsic prostaglandins. However, selective constriction of DA suggests the presence of highly specialized contractile mechanisms in DA. We previously reported that smooth muscle myosin heavy chain isoforms, SM1 and SM2, are molecular markers for smooth muscle differentiation because of their unique expression pattern during vascular development. SM1 and SM2 are generated from a single gene through developmentally regulated alternative RNA splicing; SM1 is expressed in almost all stages of differentiation of the vascular smooth muscles, but SM2 is found only after birth. METHODS AND RESULTS Immunohistochemistry was performed to study the expression of the different types of myosin heavy chain isoforms in DA of fetal and neonatal rabbits. Electron microscopic examinations were also carried out to demonstrate ultrastructural characteristics of ductus muscles. We found that SM2 is expressed before birth in the medial layer of DA, indicating advanced differentiation of smooth muscle cells in DA. The exact location of immunoreactivity for SM2 was in the smooth muscle cell of the medial layer of DA. Immunoreactivity for SM1, however, was not different for DA and adjacent great arteries. Transmission electron microscopy demonstrated greater amounts of myofilaments in medial smooth muscles of DA than those of aorta. CONCLUSIONS These results indicate that smooth muscles in DA are more differentiated than those in other arteries, which may be one of the cellular mechanisms responsible for the unique closure of DA at birth.
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Affiliation(s)
- H S Kim
- Third Department of Internal Medicine, University of Tokyo, Japan
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Strieleman PJ, Metzger BE. Glucose and scyllo-inositol impair phosphoinositide hydrolysis in the 10.5-day cultured rat conceptus: a role in dysmorphogenesis? TERATOLOGY 1993; 48:267-78. [PMID: 8248864 DOI: 10.1002/tera.1420480310] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Culture of the postimplantation rat conceptus from gestational day 9.5-10.5 in media supplemented with d-glucose or scyllo-inositol decreases tissue myo-inositol and phosphoinositides with a concomitant increase in dysmorphogenesis. A number of mitogenic agents initiate cellular proliferation and differentiation through receptors coupled to phosphoinositide hydrolysis. To test whether the decrease in conceptus phosphoinositides is associated with a reduced phosphoinositide hydrolytic response, we developed a protocol to stimulate phosphoinositide hydrolysis. Phosphoinositide hydrolysis was monitored by measurement of [3H]inositol phosphates after preincubation in serum free media. We examined the ability of serum, platelet-derived growth factor (PDGF), epidermal-derived growth factor (EGF), insulin-like growth factor 1 (IGF-1), insulin-like growth factor 2 (IGF-2), endothelin-1 (ET-1), and endothelin-2 (ET-2), to stimulate phosphoinositide hydrolysis. As measured by [3H]inositol monophosphate ([3H]InsP1) accumulation, normal rat seru, ET-1, and ET-2 stimulated phosphoinositide hydrolysis 47%, 420%, and 154% above the basal rate observed in serum free controls. EGF stimulated a statistically insignificant 15% increase while PDGF, IGF-1, or IGF-2 were without effect. We further characterized ET-1 stimulated phosphoinositide hydrolysis. Dose-response studies disclosed that incremental increases in [3H]InsP1 (129-420%) are observed over a concentration range of 10-1,000 nM. Maximal stimulation was not reached even at 1,000 nM. Temporally [3H]InsP1 and [3H]InsP3 levels increased linearly during incubation periods of 15-60 min. We further analyzed ET-1 stimulated phosphoinositide hydrolysis in 10.5-day conceptuses cultured for 24 hr in media containing high concentrations of glucose (23.3-56.6 mM) or scyllo-inositol (0.55, 5.5 mM). Under these dysmorphogenic conditions that concomitantly decrease the phosphoinositide precursor pool the response to ET-1 was blunted 28-76% for glucose and 29-65% for scyllo-inositol. This suggests that the effect of glucose and scyllo-inositol on lowering phosphoinositide precursor pools also results in a decrease in the response to agonists using the inositol/lipid intracellular pathway. This impaired signaling response may contribute to initiating dysmorphogenic events in diabetic embryopathy.
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Affiliation(s)
- P J Strieleman
- Center for Endocrinology, Metabolism and Nutrition, Northwestern University, Chicago, Illinois 60611
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Srinivasan M, Srinivasan GR, Mathé AA, Theodorsson E. Endothelin concentrations in respiration-related structures of the medulla during the perinatal period of the rat. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1993; 74:117-21. [PMID: 8403364 DOI: 10.1016/0165-3806(93)90090-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Endothelin-like immunoreactivity (ET-LI) was quantified in the developing (foetal and postnatal) rat brain stem and cerebellum using radioimmunoassay. The brain stem structures chosen for this study were (a) dorsal medullary region (DMR) including the region of nucleus tractus solitarius where the peripheral chemoreceptor afferents are known to terminate, (b) ventral medullary region (VMR) where the central chemoreceptors are thought to be located and (c) cerebellum (CER), as a control area. Compared to the prenatal period, significantly elevated concentrations of ET-LI were detected in the early postnatal period and thereafter the concentrations decreased: DMR and VMR: in comparison to the prenatal concentrations, a two-fold increase was found on the day of birth which further increased significantly (P < 0.001) on postnatal day 1 only in the region of DMR; CER: low concentrations of ET-LI were found in the early postnatal period which were not significantly different from the prenatal values. No ET-LI could be detected in any of the three regions in the adult rats. The results are discussed in view of the hypothesis that (1) endothelin appears to play an important role in the perinatal period and (2) it is involved in the chemoreceptor pathway.
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Affiliation(s)
- M Srinivasan
- Nobel Institute for Neurophysiology, Karolinska Institutet, Stockholm, Sweden
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Rosenberg AA, Kennaugh J, Koppenhafer SL, Loomis M, Chatfield BA, Abman SH. Elevated immunoreactive endothelin-1 levels in newborn infants with persistent pulmonary hypertension. J Pediatr 1993; 123:109-14. [PMID: 8320603 DOI: 10.1016/s0022-3476(05)81552-5] [Citation(s) in RCA: 174] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To study the potential role of endothelin-1, a potent endothelium-derived vasoconstrictor peptide, in the pathophysiology of persistent pulmonary hypertension of the newborn (PPHN), we measured arterial concentrations of immunoreactive endothelin-1 (irET-1) in 24 neonates with PPHN. Secondary diagnoses included meconium aspiration syndrome (13 patients), sepsis (2), congenital diaphragmatic hernia (1), asphyxia (1), pulmonary hemorrhage (1), aspiration of blood (1), and respiratory distress syndrome (1). Compared with irET-1 levels in umbilical cord blood in normal infants (15.1 +/- 4.1 pg/ml; mean +/- SEM) and in newborn infants with hyaline membrane disease who were supported by mechanical ventilation (11.8 +/- 1.2 pg/ml), infants with PPHN had markedly elevated circulating irET-1 levels (27.6 +/- 3.6 pg/ml; p < 0.01 vs cord blood, hyaline membrane disease). Infants with severe PPHN requiring extracorporeal membrane oxygenation (ECMO) therapy had higher irET-1 levels than infants with milder disease (31.0 +/- 4.7 for ECMO-treated infants vs 21.2 +/- 2.0 for non-ECMO-treated infants; p < 0.05). In patients treated without ECMO, irET-1 progressively decreased during the following 3 to 5 days, paralleling clinical improvement. In contrast, irET-1 concentrations remained elevated in infants with severe PPHN during ECMO therapy. We conclude that circulating irET-1 levels are elevated in newborn infants with PPHN, are positively correlated with disease severity, and decline with resolution of disease in patients who do not require ECMO therapy. Whether endothelin-1 contributes directly to the pathophysiology of PPHN or is simply a marker of disease activity remains speculative.
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Affiliation(s)
- A A Rosenberg
- Department of Pediatrics, University of Colorado School of Medicine, Denver
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Ekblad H, Arjamaa O, Vuolteenaho O, Kääpä P, Kero P. Plasma endothelin-1 concentrations at different ages during infancy and childhood. Acta Paediatr 1993; 82:302-3. [PMID: 8495088 DOI: 10.1111/j.1651-2227.1993.tb12665.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- H Ekblad
- Department of Pediatrics, University of Turku, Finland
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Svane D, Larsson B, Alm P, Andersson KE, Forman A. Endothelin-1: immunocytochemistry, localization of binding sites, and contractile effects in human uteroplacental smooth muscle. Am J Obstet Gynecol 1993; 168:233-41. [PMID: 8420333 DOI: 10.1016/s0002-9378(12)90919-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE Our purpose was to study the localization, distribution of binding sites, and contractile effects of endothelin-1 in human uteroplacental smooth muscle. STUDY DESIGN The tissue localization of endothelin-1, the distribution of iodine 125-labeled endothelin-1 binding sites, and the mechanical effects of endothelin-1 were studied in isolated tissues from the human uterus and placenta by immunocytochemistry, autoradiography, and organ bath experiments. RESULTS No specific endothelin-1 immunoreactivity could be detected in fetal placental tissues or in myometrium or intramyometrial arteries from term pregnant and nonpregnant women. In placental tissues a high density of iodine 125-labeled endothelin-1 binding sites was found in vessels of various sizes and in the chorionic villi, whereas the density in the jelly of Wharton was low. In myometrial tissue from pregnant and nonpregnant women a high density of iodine 125-labeled endothelin-1 binding sites was found, which in myometrium from pregnant women was mainly located to the myometrium and vascular smooth muscle. Endothelin-1 produced marked contractile responses in maternal and fetal uteroplacental vessels and in myometrial preparations. CONCLUSION Endothelin-1 may be involved in the endogenous control of uteroplacental vascular and visceral smooth muscle.
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Affiliation(s)
- D Svane
- Department of Obstetrics and Gynecology, University of Aarhus, Denmark
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Gandhi CR, Behal RH, Harvey SA, Nouchi TA, Olson MS. Hepatic effects of endothelin. Receptor characterization and endothelin-induced signal transduction in hepatocytes. Biochem J 1992; 287 ( Pt 3):897-904. [PMID: 1332687 PMCID: PMC1133091 DOI: 10.1042/bj2870897] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Endothelin, a potent vasoactive peptide originally isolated from the vascular endothelial cells, exerts glycogenolytic and vasoconstrictive actions in the perfused rat liver. In this paper we demonstrate high-affinity binding sites for endothelin-1 (ET-1) on rat hepatocytes. Upon incubation at 37 degrees C, association of ET-1 with hepatocytes occurred in a time-dependent manner, was maximal between 3 and 6 h, and subsequently declined; at this temperature ET-1 was rapidly internalized with the internalized ligand exceeding the surface-bound ligand at all time points. The rate of association of 125I-ET-1 with hepatocytes was much slower when the binding assay was performed at 4 degrees C; sequestration of ET-1 in hepatocytes was also substantially reduced at this temperature. ET-1 was extremely potent in stimulating phosphoinositide metabolism in hepatocytes, with significant activation of this signal transduction process occurring at ET-1 concentrations as low as 0.1 pM, with an EC50 of 1 pM. The effect of ET-1 was coupled via a pertussis toxin-sensitive G-protein. Cholera toxin did not affect ET-1-mediated phosphoinositide metabolism and neither toxin influenced the association of 125I-ET-1 with hepatocytes. PAGE of hepatocyte membranes following exposure of the cells to 125I-ET-1 and cross-linking revealed labelling of three major proteins with apparent molecular masses of 32, 49 and 72 kDa. 125I-ET-1 labelling of each of these proteins was inhibited by unlabelled ET-1, whereas unlabelled ET-3 inhibited the labelling of only the 32 and 49 kDa proteins. 125I-ET-3 labelled the 49 kDa protein and this labelling was inhibited by both unlabelled ET-1 and ET-3. Each of these receptors appears to be functional, since both ET-1 and ET-3 stimulated phosphoinositide metabolism in hepatocytes. Down-regulation of ET-1 association and desensitization of ET-1-induced phosphoinositide metabolism occurred upon incubation of hepatocytes with the homologous ligand. Following down-regulation, the ET-1 receptor was restored to the surface of the hepatocyte by prolonged incubation, although the ET-1-stimulated phosphoinositide response remained inhibited even after complete recovery of the ET-1 association capability. These results demonstrate the presence of multiple high-affinity receptors for ET-1 on hepatocytes and the direct action of this peptide on hepatic parenchymal cells via the phosphoinositide signal transduction pathway.
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Affiliation(s)
- C R Gandhi
- Department of Biochemistry, University of Texas Health Science Center, San Antonio 78284-7760
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Bodelsson G, Sjöberg NO, Stjernquist M. Contractile effect of endothelin in the human uterine artery and autoradiographic localization of its binding sites. Am J Obstet Gynecol 1992; 167:745-50. [PMID: 1530033 DOI: 10.1016/s0002-9378(11)91582-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE The aim was to study the effects, mode of action, and binding sites of endothelin-1 in the human uterine artery. STUDY DESIGN The contractile effect of endothelin-1 on the human uterine artery with and without endothelium and the effect of verapamil and nicardipine on the contraction was investigated in vitro. The Student t test was used. Iodine 125-endothelin-1 binding sites were localized with autoradiography. RESULTS Endothelin-1 induced a contraction that was unaffected by removal of the endothelium. Verapamil antagonized the contraction, whereas nicardipine showed no effect. Iodine 125-endothelin-1 binding sites were demonstrated in the smooth muscle layer. CONCLUSIONS These results show that endothelin-1 is a vasoconstrictor in the human uterine artery and suggest that the effect is mediated by receptors on the smooth muscle cells. The mode of action seems to involve Ca++ influx by other than dihydropyridine-sensitive Ca++ channels. Endothelin-1 does not seem to stimulate release of other endothelium-derived vasoactive agents.
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Affiliation(s)
- G Bodelsson
- Department of Obstetrics and Gynecology, University of Lund, Malmö
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MacLean MR, Templeton AG, McGrath JC. The influence of endothelin-1 on human foeto-placental blood vessels: a comparison with 5-hydroxytryptamine. Br J Pharmacol 1992; 106:937-41. [PMID: 1393291 PMCID: PMC1907685 DOI: 10.1111/j.1476-5381.1992.tb14438.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
1. The vasoconstrictor effect of endothelin-1 (3 x 10(-11) M-10(-7) M) was studied in successive generations of blood vessels of the foeto-placental vascular tree. These were the human umbilical arteries and veins, primary surface chorionic plate arteries, secondary chorionic plate arteries, tertiary surface chorionic plate arteries and veins and the secondary stem villus arterioles. The responses to endothelin-1 were compared with those to 5-hydroxytryptamine (10(-9) M-10(-5) M). Arterial preparations were gassed with 2.5% O2, 8% CO2 balance N2 and venous preparations were gassed with 5% O2, 6% CO2 balance N2 to simulate the conditions prevalent in utero. The influence of increasing the oxygen tension to 16% (that prevalent at birth) on the response to endothelin-1 on the umbilical arteries was also investigated. 2. All the arterial vessels tested were some ten times more sensitive to endothelin-1 than to 5-hydroxytryptamine and the venous preparations were ten times more sensitive to endothelin-1 than were their equivalent arteries. Increasing oxygen tension did not affect the responses to endothelin-1 in the umbilical artery. 3. Whilst the amplitude of the endothelin-1-induced response was uniform throughout the foetoplacental vascular tree, including the stem villus arterioles, the maximum response to 5-hydroxytryptamine decrease with successive generations and it had no significant effect on the stem villus arterioles.The ratios of the responses to 10- M endothelin-1: 10-7M 5-hydroxytryptamine in human umbilical arteries, primary surface chorionic plate arteries, secondary chorionic plate arteries,tertiary surface chorionic plate arteries and the secondary stem villus arterioles in the vessels (listed in order of decreasing vessel size) were 1:1.2, 1:0.36, 1:0.33, 1:0.35 and 1:0.04 respectively.4. In conclusion, endothelin-1 is a powerful vasoconstrictor at all levels of the foeto-placental vascular system including the stem villus resistance vessels. It may play an important role in maintaining foeto-plancental vascular resistance at the low oxygen tension which exists in this vascular system in utero.
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Affiliation(s)
- M R MacLean
- Autonomic Physiology Unit, Institute of Physiology, Glasgow University
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41
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Salamonsen LA, Butt AR, Macpherson AM, Rogers PA, Findlay JK. Immunolocalization of the vasoconstrictor endothelin in human endometrium during the menstrual cycle and in umbilical cord at birth. Am J Obstet Gynecol 1992; 167:163-7. [PMID: 1442920 DOI: 10.1016/s0002-9378(11)91652-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Our objective was to determine the localization of immunoreactive endothelin in human cyclic endometrium and in umbilical cord during normal delivery and after cesarean section. STUDY DESIGN Fixed dated endometrial tissue (n = 41) and umbilical cord (n = 6) were subjected to immunohistochemistry with an antiserum cross reacting with endothelin-1, -2 and -3. RESULTS Low levels of stromal endometrial staining were seen throughout the cycle. The strongest staining was in luminal epithelium throughout the secretory phase and in glandular epithelium in the late-secretory phase. In umbilical cord the most intense immunoreactivity was present on the amnion cells on the outer cord, with some staining in intermittent cells in the Wharton's jelly and in umbilical vein cells. No differences were detected between cord from normal delivery or cesarean section. CONCLUSION A paracrine role is suggested for endothelin in regulation of endometrial function and a role in vasoconstriction in the umbilical cord at birth.
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Affiliation(s)
- L A Salamonsen
- Prince Henry's Institute of Medical Research, Monash University, Clayton, Australia
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42
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Leppäluoto J, Ruskoaho H. Endothelin peptides: biological activities, cellular signalling and clinical significance. Ann Med 1992; 24:153-61. [PMID: 1385714 DOI: 10.3109/07853899209147813] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Endothelins (ET-1, ET-2 and ET-3) are a family of 21 amino acid peptides produced by endothelial cells. They are thought to regulate the local vasomotor tone with endothelium-derived relaxing factors. ETs are the most potent vasoconstrictor substances yet identified and veins and renal vasculature are the most sensitive targets. They reduce cardiac output and have positive inotropic and chronotropic effects. ETs increase the secretion of atrial natriuretic peptide (ANP), aldosterone and catecholamines but reduce renal blood flow and glomerular filtration and they also have mitogenic properties. ETs bind to receptors (ETA and ETB), activate phospholipase C, modulate intracellular Ca2+ concentration and open Ca2+ channels. Vasoactive agents (adrenaline, angiotensin, vasopressin, thrombin, endotoxins) and hypoxia stimulate the release of ET and also ET gene expression. Raised concentrations of plasma ET have been found to occur in several clinical conditions such as hypertension, myocardial infarction, cardiogenic shock, pregnancy induced hypertension, arteriosclerosis, Raynaud's disease, subarachnoid haemorrhage, uraemia, ulcerative colitis, Crohn's disease and surgical operations suggesting that ETs have a role in several patophysiological processes.
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Affiliation(s)
- J Leppäluoto
- Department of Physiology, University of Oulu, Finland
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Clark BA, Halvorson L, Sachs B, Epstein FH. Plasma endothelin levels in preeclampsia: elevation and correlation with uric acid levels and renal impairment. Am J Obstet Gynecol 1992; 166:962-8. [PMID: 1532292 DOI: 10.1016/0002-9378(92)91372-h] [Citation(s) in RCA: 124] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE The purpose of this study was to determine if endothelin levels are elevated in women with preeclampsia and if these levels correlated with other laboratory features of disease severity. STUDY DESIGN Parameters were compared in four groups of women volunteers by means of analysis of variance: (1) 16 women with preeclamptic pregnancies, (2) 11 pregnant women without preeclampsia, of similar lengths of gestation, (3) six otherwise normal women with pregnancies at term or beyond (greater than 38 weeks), and (4) 22 normotensive young women. RESULTS Endothelin levels were elevated in women with preeclampsia as compared with those of gestation-matched pregnant and nonpregnant controls (22.6 +/- 2.0 vs 12.0 +/- 1.0 vs 10.4 +/- 1.3 pmol/L, p less than 0.005, preeclampsia vs controls) and also were increased in late gestation (17.7 +/- 2.0 pmol/L). Endothelin correlated positively with plasma levels of uric acid (r = 0.698, p less than 0.005) and inversely with creatinine clearance (r = -0.659, p less than 0.05). CONCLUSION Circulating endothelin levels are elevated in women with preeclampsia and correlate closely with serum uric acid levels and measures of renal dysfunction. These observations suggest that endothelin may contribute to renal vasoconstriction in preeclampsia.
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Affiliation(s)
- B A Clark
- Department of Medicine, Beth Israel Hospital, Harvard Medical School, Boston, MA 02215
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Romero R, Avila C, Edwin SS, Mitchell MD. Endothelin-1,2 levels are increased in the amniotic fluid of women with preterm labor and microbial invasion of the amniotic cavity. Am J Obstet Gynecol 1992; 166:95-9. [PMID: 1733226 DOI: 10.1016/0002-9378(92)91837-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The purpose of this study was to determine the effect of gestational age, labor, and microbial invasion of the amniotic cavity on amniotic fluid concentrations of endothelin-1,2. Amniotic fluid was retrieved by amniocentesis from 148 women: patients at term with and without labor, patients with preterm labor with and without intraamniotic infection, and women in the second trimester of pregnancy. Endothelin-1,2 was measured by a sensitive and specific radioimmunoassay. Immunoreactive endothelin-1,2 was detectable in all samples of human amniotic fluid. Advancing gestational age and spontaneous term labor did not result in changes in amniotic fluid concentrations of endothelin-1,2. Women with preterm labor and positive amniotic fluid cultures for microorganisms had higher amniotic fluid concentrations of endothelin-1,2 than did those without microbial invasion of the amniotic cavity (p less than 0.05). These results support a role for endothelins in the mechanisms responsible for preterm delivery associated with intraamniotic infection.
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Affiliation(s)
- R Romero
- Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut
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Abstract
1. The human fetal extracorporeal circulation is normally a vasodilated, low pressure system. 2. As this vasculature lacks innervation, autacoids have been postulated as being of great importance in controlling its tone. 3. This has now been confirmed by pharmacological in vitro techniques, particularly utilizing perfusion of the isolated umbilical cord and placental lobule. 4. The fetal umbilical-placental vessels are sensitive to a wide range of vasoconstrictor autacoids, some of which can cause intense vasospasm. 5. Thromboxane A2 receptors have been identified in both umbilical vein and placental villous vessels. 6. Prostacyclin and endothelial cell-derived relaxing factor (or nitric oxide) may be largely responsible for the low vascular resistance normally found in the fetal extracorporeal circulation. 7. Immediately after birth it is likely that stimuli such as cooling, stretching and handling of the umbilical cord cause release of eicosanoids and other autacoids from the vessels, leading to their complete closure.
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Affiliation(s)
- W A Walters
- Discipline of Reproductive Medicine, Faculty of Medicine, University of Newcastle, NSW Australia
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Samuelson UE, Hedén P, Jernbeck J, Wiklund NP. Endothelin reduces blood flow in experimental skin flaps. SCANDINAVIAN JOURNAL OF PLASTIC AND RECONSTRUCTIVE SURGERY AND HAND SURGERY 1992; 26:241-5. [PMID: 1470869 DOI: 10.3109/02844319209015265] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An island buttock flap based on the deep circumflex iliac artery and vein was raised in four pigs. Cutaneous laser Doppler blood flow (LDF) and total venous outflow (VO) from the flaps were measured. Intra-arterial infusion of endothelin-1 (0.3-2.5 nmol) through a branch of the deep circumflex iliac artery induced a pronounced and long lasting decrease in both LDF and VO. The maximal mean reductions being 95.3% and 73%, respectively, were seen within 5 minutes of the infusion. Intra-arterial infusions of endothelin in the circumflex iliac artery on the contralateral side caused a considerable reduction in intact skin LDF. Endothelin has potent vasoconstricting properties and its possible release and effect must be considered in reconstructive surgery.
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Affiliation(s)
- U E Samuelson
- Department of Plastic and Reconstructive Surgery, Sabbatsbergs Hospital, Stockholm, Sweden
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Hemsén A, Gillis C, Larsson O, Haegerstrand A, Lundberg JM. Characterization, localization and actions of endothelins in umbilical vessels and placenta of man. ACTA PHYSIOLOGICA SCANDINAVICA 1991; 143:395-404. [PMID: 1667718 DOI: 10.1111/j.1748-1716.1991.tb09251.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Endothelin-like immunoreactivity was observed in the endothelial lining of umbilical vein and artery as well as in the epithelium of the amniotic membrane. High levels of endothelin-like immunoreactivity (0.4-1.4 pmol g-1) were detected in human amniotic membrane, umbilical vessels and placenta. The concentration of endothelin-like immunoreactivity in the amniotic fluid was much higher (77 pmol l-1) than in umbilical cord plasma (10 pmol l-1). Characterization by reverse phase HPLC revealed that most of the endothelin-like immunoreactivity eluted in the position of synthetic endothelin-1 or oxidized endothelin-1. Specific, high affinity binding sites for endothelin-1 were present in placenta and umbilical artery. Endothelin binding sites were also found in cultured smooth muscle cells from the umbilical artery and vein. In the placenta, endothelin-1 and -3 were almost equipotent as competing ligands for endothelin-1 binding sites, whereas in the umbilical artery endothelin-3 was much less potent than endothelin-1. Scatchard analysis of the binding for placental membranes displayed a straight line (r = -0.994) indicating a single class of endothelin receptors with a Kd-value of 80 pmol l-1 and Bmax of 113 fmol mg-1. Endothelin-1 caused potent contractions of umbilical arteries and veins with threshold effects at 10 pmol l-1 while endothelin-3 had no contractile effect up to 10(-7) mol l-1. It is concluded that endothelin-1 predominates over other endothelins in umbilical vessels, amnion and placenta, and high levels of endothelin-1 was observed in foetal circulation and amniotic fluid. Endothelin-receptors seem to be of different types in placenta (ETB type) and umbilical vessels (ETA type).
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Affiliation(s)
- A Hemsén
- Department of Pharmacology, Karolinska Institute, Stockholm, Sweden
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Abstract
The effect of endothelin-1 on vascular tension has been investigated in human umbilical cord vessels perfused in vitro and compared to that of serotonin. Both autacoids induced vasoconstrictions in the arteries and in the veins, all responses being clearly dose-dependent. Endothelin-1 was found to be most potent, eliciting visible pressure changes in concentrations of 10(-11)-10(-10) M. The responses to 10(-9) M endothelin-1 in the veins increased markedly at repeated stimulations. In the arteries a potentiating effect on the serotonin response was observed after exposure to 10(-11) M of endothelin-1. The results signal that the peptide may be of significance in the regulation of umbilicoplacental blood flow.
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Affiliation(s)
- G Haugen
- Department of Obstetrics and Gynecology, National Hospital, University of Oslo, Norway
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49
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Affiliation(s)
- A L Boura
- Discipline of Reproductive Medicine, Faculty of Medicine, University of Newcastle, N.S.W., Australia
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Gu J, Pinheiro JM, Yu CZ, D'Andrea M, Muralidharan S, Malik A. Detection of endothelin-like immunoreactivity in epithelium and fibroblasts of the human umbilical cord. Tissue Cell 1991; 23:437-44. [PMID: 1926136 DOI: 10.1016/0040-8166(91)90002-b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We studied tissue sections of freshly obtained full-term and premature human umbilical cords using polyclonal antibody to endothelin and immunocytochemistry. Endothelin immunoreactivity was detected in the cytoplasm of epithelial cells and primitive fibroblasts, but not in the endothelial cells of both full-term and premature umbilical cords. Immunoelectron microscopy using indirect immunogold staining technique localized endothelin immunoreactivity to the cytoplasm of the epithelial cells and fibroblasts but not confined to any particular structures. No endothelin immunoreactivity was detected in the nucleus or on the cell membrane. Pre-absorption tests with synthetic endothelin-1, -2, and -3 independently established that the immunoreactivity represented endothelin-1 and -2, but not -3. The presence of endothelin-1 and -2-like immunoreactive materials in epithelial cells and fibroblasts of human umbilical cord suggests a role of endothelin in parturition.
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Affiliation(s)
- J Gu
- Deborah Research Institute, Browns Mills, New Jersey 08015-1799
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