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Yarboro MT, Boatwright N, Sekulich DC, Hooper CW, Wong T, Poole SD, Berger CD, Brown AJ, Jetter CS, Sucre JMS, Shelton EL, Reese J. A novel role for PGE 2-EP 4 in the developmental programming of the mouse ductus arteriosus: consequences for vessel maturation and function. Am J Physiol Heart Circ Physiol 2023; 325:H687-H701. [PMID: 37566109 PMCID: PMC10643004 DOI: 10.1152/ajpheart.00294.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/11/2023] [Accepted: 07/24/2023] [Indexed: 08/12/2023]
Abstract
The ductus arteriosus (DA) is a vascular shunt that allows oxygenated blood to bypass the developing lungs in utero. Fetal DA patency requires vasodilatory signaling via the prostaglandin E2 (PGE2) receptor EP4. However, in humans and mice, disrupted PGE2-EP4 signaling in utero causes unexpected patency of the DA (PDA) after birth, suggesting another role for EP4 during development. We used EP4-knockout (KO) mice and acute versus chronic pharmacological approaches to investigate EP4 signaling in DA development and function. Expression analyses identified EP4 as the primary EP receptor in the DA from midgestation to term; inhibitor studies verified EP4 as the primary dilator during this period. Chronic antagonism recapitulated the EP4 KO phenotype and revealed a narrow developmental window when EP4 stimulation is required for postnatal DA closure. Myography studies indicate that despite reduced contractile properties, the EP4 KO DA maintains an intact oxygen response. In newborns, hyperoxia constricted the EP4 KO DA but survival was not improved, and permanent remodeling was disrupted. Vasomotion and increased nitric oxide (NO) sensitivity in the EP4 KO DA suggest incomplete DA development. Analysis of DA maturity markers confirmed a partially immature EP4 KO DA phenotype. Together, our data suggest that EP4 signaling in late gestation plays a key developmental role in establishing a functional term DA. When disrupted in EP4 KO mice, the postnatal DA exhibits signaling and contractile properties characteristic of an immature DA, including impairments in the first, muscular phase of DA closure, in addition to known abnormalities in the second permanent remodeling phase.NEW & NOTEWORTHY EP4 is the primary EP receptor in the ductus arteriosus (DA) and is critical during late gestation for its development and eventual closure. The "paradoxical" patent DA (PDA) phenotype of EP4-knockout mice arises from a combination of impaired contractile potential, altered signaling properties, and a failure to remodel associated with an underdeveloped immature vessel. These findings provide new mechanistic insights into women who receive NSAIDs to treat preterm labor, whose infants have unexplained PDA.
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Affiliation(s)
- Michael T Yarboro
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States
| | - Naoko Boatwright
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Deanna C Sekulich
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Christopher W Hooper
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Ting Wong
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Stanley D Poole
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Courtney D Berger
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Alexus J Brown
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Christopher S Jetter
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Jennifer M S Sucre
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Elaine L Shelton
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States
| | - Jeff Reese
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States
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2
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Owen JC, Garrick SP, Peterson BM, Berger PJ, Nold MF, Sehgal A, Nold-Petry CA. The role of interleukin-1 in perinatal inflammation and its impact on transitional circulation. Front Pediatr 2023; 11:1130013. [PMID: 36994431 PMCID: PMC10040554 DOI: 10.3389/fped.2023.1130013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 02/13/2023] [Indexed: 03/31/2023] Open
Abstract
Preterm birth is defined as delivery at <37 weeks of gestational age (GA) and exposes 15 million infants worldwide to serious early life diseases. Lowering the age of viability to 22 weeks GA entailed provision of intensive care to a greater number of extremely premature infants. Moreover, improved survival, especially at extremes of prematurity, comes with a rising incidence of early life diseases with short- and long-term sequelae. The transition from fetal to neonatal circulation is a substantial and complex physiologic adaptation, which normally happens rapidly and in an orderly sequence. Maternal chorioamnionitis or fetal growth restriction (FGR) are two common causes of preterm birth that are associated with impaired circulatory transition. Among many cytokines contributing to the pathogenesis of chorioamnionitis-related perinatal inflammatory diseases, the potent pro-inflammatory interleukin (IL)-1 has been shown to play a central role. The effects of utero-placental insufficiency-related FGR and in-utero hypoxia may also be mediated, in part, via the inflammatory cascade. In preclinical studies, blocking such inflammation, early and effectively, holds great promise for improving the transition of circulation. In this mini-review, we outline the mechanistic pathways leading to abnormalities in transitional circulation in chorioamnionitis and FGR. In addition, we explore the therapeutic potential of targeting IL-1 and its influence on perinatal transition in the context of chorioamnionitis and FGR.
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Affiliation(s)
- Josephine C. Owen
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Steven P. Garrick
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Briana M. Peterson
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Philip J. Berger
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Marcel F. Nold
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
| | - Arvind Sehgal
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
| | - Claudia A. Nold-Petry
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- Correspondence: Claudia A. Nold-Petry
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3
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Abstract
The microcirculation maintains tissue homeostasis through local regulation of blood flow and oxygen delivery. Perturbations in microvascular function are characteristic of several diseases and may be early indicators of pathological changes in the cardiovascular system and in parenchymal tissue function. These changes are often mediated by various reactive oxygen species and linked to disruptions in pathways such as vasodilation or angiogenesis. This overview compiles recent advances relating to redox regulation of the microcirculation by adopting both cellular and functional perspectives. Findings from a variety of vascular beds and models are integrated to describe common effects of different reactive species on microvascular function. Gaps in understanding and areas for further research are outlined. © 2020 American Physiological Society. Compr Physiol 10:229-260, 2020.
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Affiliation(s)
- Andrew O Kadlec
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - David D Gutterman
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Department of Medicine-Division of Cardiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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4
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Villamor E, Moreno L, Mohammed R, Pérez-Vizcaíno F, Cogolludo A. Reactive oxygen species as mediators of oxygen signaling during fetal-to-neonatal circulatory transition. Free Radic Biol Med 2019; 142:82-96. [PMID: 30995535 DOI: 10.1016/j.freeradbiomed.2019.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 03/22/2019] [Accepted: 04/08/2019] [Indexed: 12/20/2022]
Abstract
Reactive oxygen species (ROS) are frequently seen as pathological agents of oxidative stress. However, ROS are not always deleterious and can also act as cell signaling molecules. Vascular oxygen sensing and signaling during fetal-to-neonatal circulatory transition is a remarkable example of the physiological regulatory actions of ROS. The fetal relative hypoxic environment induces hypoxic pulmonary vasoconstriction (HPV) and ductus arteriosus (DA) relaxation favoring the presence of high pulmonary vascular resistance and right-to-left ductal shunt. At birth, the increase in oxygen tension causes relaxation of pulmonary arteries (PAs) and normoxic DA vasoconstriction (NDAV), thus diverting blood flow to the lungs. Although the response to changes in oxygen tension is diametrically opposite, the mechanisms responsible for HPV and NDAV appear to be the result of a similar interaction between triggering and modulating factors that lead to an increase in cytosolic Ca2+ concentration and Ca2+ sensitization of the contractile apparatus. Growing evidence points to an increase in ROS (mitochondria- and/or NADPH-derived superoxide and/or H2O2), leading to inhibition of voltage-gated K+ channels, membrane depolarization, and activation of voltage-gated L-type Ca2+ channels as critical events in the signaling pathway of both HPV and NDAV. Several groups of investigators have completed this pathway adding other elements such as neutral sphingomyelinase-derived ceramide, the sarcoplasmic/endoplasmic reticulum (through ryanodine and inositol 1,4,5-trisphosphate receptors), Rho kinase-mediated Ca2+ sensitization, or transient receptor potential channels. The present review focus on the role of ROS as mediators of the homeostatic oxygen sensing system during fetal and neonatal life not only in the PAs and DA but also in systemic arteries.
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Affiliation(s)
- Eduardo Villamor
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, the Netherlands.
| | - Laura Moreno
- Department of Pharmacology, School of Medicine, Universidad Complutense de Madrid, Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Riazzudin Mohammed
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Developmental Biology (GROW), Maastricht, the Netherlands
| | - Francisco Pérez-Vizcaíno
- Department of Pharmacology, School of Medicine, Universidad Complutense de Madrid, Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Angel Cogolludo
- Department of Pharmacology, School of Medicine, Universidad Complutense de Madrid, Centro de Investigaciones Biomédicas en Red de Enfermedades Respiratorias (CIBERES), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
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5
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Crockett SL, Berger CD, Shelton EL, Reese J. Molecular and mechanical factors contributing to ductus arteriosus patency and closure. CONGENIT HEART DIS 2018; 14:15-20. [PMID: 30468303 DOI: 10.1111/chd.12714] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 10/16/2018] [Indexed: 12/30/2022]
Abstract
Regulation of the ductus arteriosus, an essential fetal vessel connecting the pulmonary artery and aorta, is complex. Failure of this vessel to close after birth may result in a persistent left-to-right shunt through the patent ductus arteriosus, a condition associated with significant morbidities. Numerous factors contribute to the shift from fetal ductus patency to postnatal closure, requiring precise coordination of molecular cues with biomechanical forces and underlying genetic influences. Despite significant advances, questions remain regarding signaling dynamics and the natural time course of ductus closure, particularly in preterm neonates. This review highlights the contributions of early investigators and more recent clinician scientists to our understanding of the molecular and mechanical factors that mediate ductus patency and closure.
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Affiliation(s)
- Stacey L Crockett
- Mildred T. Stahlman Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Courtney D Berger
- Mildred T. Stahlman Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Elaine L Shelton
- Mildred T. Stahlman Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Jeff Reese
- Mildred T. Stahlman Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
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6
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Yarboro MT, Durbin MD, Herington JL, Shelton EL, Zhang T, Ebby CG, Stoller JZ, Clyman RI, Reese J. Transcriptional profiling of the ductus arteriosus: Comparison of rodent microarrays and human RNA sequencing. Semin Perinatol 2018; 42:212-220. [PMID: 29910032 PMCID: PMC6064668 DOI: 10.1053/j.semperi.2018.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
DA closure is crucial for the transition from fetal to neonatal life. This closure is supported by changes to the DA's signaling and structural properties that distinguish it from neighboring vessels. Examining transcriptional differences between these vessels is key to identifying genes or pathways responsible for DA closure. Several microarray studies have explored the DA transcriptome in animal models but varied experimental designs have led to conflicting results. Thorough transcriptomic analysis of the human DA has yet to be performed. A clear picture of the DA transcriptome is key to guiding future research endeavors, both to allow more targeted treatments in the clinical setting, and to understand the basic biology of DA function. In this review, we use a cross-species cross-platform analysis to consider all available published rodent microarray data and novel human RNAseq data in order to provide high priority candidate genes for consideration in future DA studies.
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Affiliation(s)
- Michael T. Yarboro
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232
| | - Matthew D. Durbin
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, 46202
| | - Jennifer L. Herington
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | - Elaine L. Shelton
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | - Tao Zhang
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Cris G. Ebby
- Rutgers New Jersey Medical School, Newark, NJ 08901
| | - Jason Z. Stoller
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Ronald I. Clyman
- Department of Pediatrics, Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94143
| | - Jeff Reese
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Vanderbilt University, 1125 Light Hall/MRB IV Bldg., 2215 B Garland Ave., Nashville, TN 37232; Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232.
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7
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Abstract
The ductus arteriosus is typically viewed as a mammalian fetal blood vessel providing a right-to-left shunt of right ventricular outflow away from the lungs and to the systemic circuit, that must close at birth. This review provides a wider comparative examination of the ductus arteriosus in lungfish, reptiles, birds, and mammals. The ductus arteriosus evolved with the lung in the ancestors of the lungfish as a connection between the pulmonary arteries and dorsal aorta. During embryonic development, reptiles, birds, and mammals all possess either one or two paired ductus arteriosi that provide a fetal shunt of blood away from the lungs. Differences in the fetal circulatory arrangement are seen between these groups and this influences the importance of the ductus arteriosus as an embryonic shunt. The ductus arteriosus from lungfish and tetrapod vertebrates is an oxygen sensitive blood vessel, with shared conserved pathways involved in oxygen sensing. By expanding studies into more comparative models such as lungfish or developing birds a better understanding of the physiology of the ductus arteriosus can be developed.
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Affiliation(s)
- Edward M Dzialowski
- Developmental Integrative Biology Research Group, Department of Biological Science, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203.
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8
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Toyoshima K, Momma K, Ishii T, Nakanishi T. Dilatation of the ductus arteriosus by diazoxide in fetal and neonatal rats. Pediatr Int 2017; 59:1246-1251. [PMID: 28901668 DOI: 10.1111/ped.13424] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 07/04/2017] [Accepted: 07/12/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Diazoxide, an ATP-sensitive potassium channel opener, is the main therapeutic agent for treating hyperinsulinemic hypoglycemia. The aim of this study was to determine the in vivo ductus arteriosus (DA)-dilating effects of diazoxide in fetal and neonatal rats. METHODS Near-term rat pups delivered via cesarean section were housed at 33°C. After rapid whole-body freezing, the ductus arteriosus (DA) diameter was measured using a microscope and a micrometer. Full-term pregnant rats (gestational day 21) were injected i.p. with diazoxide (10 and 100 mg/kg) 4 h before delivery, and the neonatal DA diameter was measured at 0, 30, or 60 min after birth. The newborn rats were also injected i.p. with diazoxide (10 and 100 mg/kg) at birth or 60 min after birth. DA was measured at 0, 30, or 60 min after injection. In the fetal investigation, the effect of diazoxide was studied via simultaneous application of indomethacin (10 mg/kg) and L-nitroarginine methyl ester (L-NAME) on gestational days 21 and 19. RESULTS The control rats had rapid postnatal DA constriction (diameter, 0.80 and 0.08 mm at 0 and 60 min after birth, respectively). Diazoxide had a dose-dependent inhibitory effect on postnatal DA constriction. Prenatal diazoxide (10 mg/kg) inhibited postnatal DA closure (0.20 mm at 60 min after birth). The diazoxide injection (10 mg) at birth inhibited postnatal DA closure (0.14 mm at 60 min after birth). Diazoxide injection in 60-min-old rats dilated the constricted DA at 60 min (0.10 mm vs. 0.02 mm in the controls). In the fetal investigation, diazoxide inhibited the fetal DA constrictive effect of indomethacin and L-NAME. CONCLUSION Diazoxide attenuates postnatal DA constriction and dilates a closing DA in fetal and neonatal rats.
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Affiliation(s)
- Katsuaki Toyoshima
- Division of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan.,Division of Neonatology, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Kazuo Momma
- Division of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan
| | - Tetsuko Ishii
- Division of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan
| | - Toshio Nakanishi
- Division of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan
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9
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Hooper CW, Delaney C, Streeter T, Yarboro MT, Poole S, Brown N, Slaughter JC, Cotton RB, Reese J, Shelton EL. Selective serotonin reuptake inhibitor exposure constricts the mouse ductus arteriosus in utero. Am J Physiol Heart Circ Physiol 2016; 311:H572-81. [PMID: 27371685 DOI: 10.1152/ajpheart.00822.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 06/18/2016] [Indexed: 12/22/2022]
Abstract
Use of selective serotonin reuptake inhibitors (SSRIs) is common during pregnancy. Fetal exposure to SSRIs is associated with persistent pulmonary hypertension of the newborn (PPHN); however, a direct link between the two has yet to be established. Conversely, it is well known that PPHN can be caused by premature constriction of the ductus arteriosus (DA), a fetal vessel connecting the pulmonary and systemic circulations. We hypothesized that SSRIs could induce in utero DA constriction. Using isolated vessels and whole-animal models, we sought to determine the effects of two commonly prescribed SSRIs, fluoxetine and sertraline, on the fetal mouse DA. Cannulated vessel myography studies demonstrated that SSRIs caused concentration-dependent DA constriction and made vessels less sensitive to prostaglandin-induced dilation. Moreover, in vivo studies showed that SSRI-exposed mice had inappropriate DA constriction in utero. Taken together, these findings establish that SSRIs promote fetal DA constriction and provide a potential mechanism by which SSRIs could contribute to PPHN.
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Affiliation(s)
- Christopher W Hooper
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Cassidy Delaney
- Department of Pediatrics, University of Colorado, Denver, Colorado
| | - Taylor Streeter
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Michael T Yarboro
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Stanley Poole
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Naoko Brown
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - James C Slaughter
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Robert B Cotton
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jeff Reese
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Elaine L Shelton
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee;
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Kajimura I, Akaike T, Minamisawa S. Lipopolysaccharide Delays Closure of the Rat Ductus Arteriosus by Induction of Inducible Nitric Oxide Synthase But Not Prostaglandin E 2. Circ J 2016; 80:703-11. [DOI: 10.1253/circj.cj-15-1053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ichige Kajimura
- Department of Cell Physiology, The Jikei University School of Medicine
| | - Toru Akaike
- Department of Cell Physiology, The Jikei University School of Medicine
| | - Susumu Minamisawa
- Department of Cell Physiology, The Jikei University School of Medicine
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11
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Effects of Advancing Gestation and Non-Caucasian Race on Ductus Arteriosus Gene Expression. J Pediatr 2015; 167:1033-41.e2. [PMID: 26265282 PMCID: PMC4661123 DOI: 10.1016/j.jpeds.2015.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 06/26/2015] [Accepted: 07/08/2015] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To identify genes affected by advancing gestation and racial/ethnic origin in human ductus arteriosus (DA). STUDY DESIGN We collected 3 sets of DA tissue (n = 93, n = 89, n = 91; total = 273 fetuses) from second trimester pregnancies. We examined four genes, with DNA polymorphisms that distribute along racial lines, to identify "Caucasian" and "non-Caucasian" DA. We used real time polymerase chain reaction to measure RNA expression of 48 candidate genes involved in functional closure of the DA, and used multivariable regression analyses to examine the relationships between advancing gestation, "non-Caucasian" race, and gene expression. RESULTS Mature gestation and non-Caucasian race are significant predictors for identifying infants who will close their patent DA when treated with indomethacin. Advancing gestation consistently altered gene expression in pathways involved with oxygen-induced constriction (eg, calcium-channels, potassium-channels, and endothelin signaling), contractile protein maturation, tissue remodeling, and prostaglandin and nitric oxide signaling in all 3 tissue sets. None of the pathways involved with oxygen-induced constriction appeared to be altered in "non-Caucasian" DA. Two genes, SLCO2A1 and NOS3, (involved with prostaglandin reuptake/metabolism and nitric oxide production, respectively) were consistently decreased in "non-Caucasian" DA. CONCLUSIONS Prostaglandins and nitric oxide are the most important vasodilators opposing DA closure. Indomethacin inhibits prostaglandin production, but not nitric oxide production. Because decreased SLCO2A1 and NOS3 expression can lead to increased prostaglandin and decreased nitric oxide concentrations, we speculate that prostaglandin-mediated vasodilation may play a more dominant role in maintaining the "non-Caucasian" patent DA, making it more likely to close when inhibited by indomethacin.
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12
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Loomba R, Nijhawan K. Ibuprofen Versus Indomethacin for Medical Closure of the Patent Arterial Duct: A Pooled Analysis by Route of Administration. Cureus 2015; 7:e274. [PMID: 26180698 PMCID: PMC4494534 DOI: 10.7759/cureus.274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 06/03/2015] [Indexed: 11/23/2022] Open
Abstract
Introduction: Preterm infants are at increased risk of having a patent arterial duct (PAD). PADs may cause congestive heart failure, respiratory distress, necrotizing enterocolitis, and renal impairment. Consequently, in some infants, it becomes necessary to attempt closure of the PAD. Surgical closure can be difficult in small infants and is not without its risks; thus, medical closure offers advantages. Cyclooxygenase inhibitors have been used for medical closure of the PAD with both ibuprofen and indomethacin having been used clinically. Methods: We performed a systematic review of the literature to identify all studies comparing ibuprofen and indomethacin. Studies comparing ibuprofen and indomethacin for closure of the PAD in premature infants were included in the meta-analysis. A subanalysis was performed to compare the route of administration. Efficacy endpoints studied were PAD closure and surgical ligation while adverse effects studied were death in the first month of life, necrotizing enterocolitis, gastrointestinal bleeding, intestinal perforation, bronchopulmonary dysplasia in the first month of life, Grade 3 or 4 intraventricular hemorrhage, and change in the serum creatinine after treatment. Results: Ibuprofen and indomethacin were equally effective in closing the PAD in premature infants and demonstrated no difference in the incidence of adverse events. In respect to the route of administration, oral ibuprofen was as effective as intravenous indomethacin. When comparing both drugs via the intravenous route, the only difference noted between the ibuprofen and indomethacin was that ibuprofen was associated with a lesser increase in serum creatinine after treatment. Conclusion: Ibuprofen and indomethacin are equally effective in PAD closure without any difference in the incidence of adverse events. Importantly, oral ibuprofen was as effective as intravenous indomethacin.
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Affiliation(s)
- Rohit Loomba
- Cardiology Dept., Children's Hospital of Wisconsin
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13
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El-Khuffash A, Jain A, Corcoran D, Shah PS, Hooper CW, Brown N, Poole SD, Shelton EL, Milne GL, Reese J, McNamara PJ. Efficacy of paracetamol on patent ductus arteriosus closure may be dose dependent: evidence from human and murine studies. Pediatr Res 2014; 76:238-44. [PMID: 24941212 PMCID: PMC4321957 DOI: 10.1038/pr.2014.82] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 02/19/2014] [Indexed: 01/14/2023]
Abstract
BACKGROUND We evaluated the clinical effectiveness of variable courses of paracetamol on patent ductus arteriosus (PDA) closure and examined its effect on the in vitro term and preterm murine ductus arteriosus (DA). METHODS Neonates received one of the following three paracetamol regimens: short course of oral paracetamol (SCOP), long course of oral paracetamol (LCOP), and intravenous paracetamol (IVP) for 2-6 d. Pressure myography was used to examine changes in vasomotor tone of the preterm and term mouse DA in response to paracetamol or indomethacin. Their effect on prostaglandin synthesis by DA explants was measured by mass spectroscopy. RESULTS Twenty-one preterm infants were included. No changes in PDA hemodynamics were seen in SCOP infants (n = 5). The PDA became less significant and eventually closed in six LCOP infants (n = 7). PDA closure was achieved in eight IVP infants (n = 9). On pressure myograph, paracetamol induced a concentration-dependent constriction of the term mouse DA, up to 30% of baseline (P < 0.01), but required >1 µmol/l. Indomethacin induced greater DA constriction and suppression of prostaglandin synthesis (P < 0.05). CONCLUSION The clinical efficacy of paracetamol on PDA closure may depend on the duration of treatment and the mode of administration. Paracetamol is less potent than indomethacin for constriction of the mouse DA in vitro.
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Affiliation(s)
| | - Amish Jain
- Department of Pediatrics, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - David Corcoran
- Department of Pediatrics, The Rotunda Hospital, Dublin, Ireland
| | - Prakesh S. Shah
- Department of Pediatrics, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Christopher W. Hooper
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Naoko Brown
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Stanley D. Poole
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Elaine L. Shelton
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Ginger L. Milne
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jeff Reese
- Division of Neonatology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Patrick J. McNamara
- Department of Neonatology, The Hospital for Sick Children, Toronto, Ontario, Canada,Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
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14
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Baragatti B, Ciofini E, Sodini D, Luin S, Scebba F, Coceani F. Hydrogen sulfide in the mouse ductus arteriosus: a naturally occurring relaxant with potential EDHF function. Am J Physiol Heart Circ Physiol 2013; 304:H927-34. [PMID: 23376828 DOI: 10.1152/ajpheart.00718.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We have previously reported that bradykinin relaxes the fetal ductus arteriosus via endothelium-derived hyperpolarizing factor (EDHF) when other naturally occurring relaxants (prostaglandin E2, nitric oxide, and carbon monoxide) are suppressed, but the identity of the agent could not be ascertained. Here, we have examined in the mouse whether hydrogen sulfide (H2S) is a relaxant of the ductus and, if so, whether it may also function as an EDHF. We found in the vessel transcripts for the H2S synthetic enzymes, cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS), and the presence of these enzymes was confirmed by immunofluorescence microscopy. CSE and CBS were distributed across the vessel wall with the former prevailing in the intimal layer. Both enzymes occurred within the endoplasmic reticulum of endothelial and muscle cells, whereas only CSE was located also in the plasma membrane. The isolated ductus contracted to inhibitors of CSE (d,l-propargylglycine, PPG) and CBS (amino-oxyacetic acid), and PPG contraction was attenuated by removal of the endothelium. EDHF-mediated bradykinin relaxation was curtailed by both PPG and amino-oxyacetic acid, whereas the relaxation to sodium nitroprusside was not affected by either treatment. The H2S donor sodium hydrogen sulfide (NaHS) was also a potent, concentration-dependent relaxant. We conclude that the ductus is endowed with a H2S system exerting a tonic relaxation. In addition, H2S, possibly via an overriding CSE source, qualifies as an EDHF. These findings introduce a novel vasoregulatory mechanism into the ductus, with implications for antenatal patency of the vessel and its transitional adjustments at birth.
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15
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Reese J, Veldman A, Shah L, Vucovich M, Cotton RB. Inadvertent relaxation of the ductus arteriosus by pharmacologic agents that are commonly used in the neonatal period. Semin Perinatol 2010; 34:222-30. [PMID: 20494739 PMCID: PMC2920501 DOI: 10.1053/j.semperi.2010.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Premature birth and disruption of the normal maturation process leave the immature ductus arteriosus unable to respond to postnatal cues for closure. Strategies that advocate conservative management of the patent ductus arteriosus (PDA) in premature infants are dependent on identification of the symptomatic PDA and understanding the risk factors that predispose to PDA. Exposure of premature infants to unintended vasodilatory stimuli may be one of the risk factors for PDA that is under recognized. In this article, we summarize the clinical factors that are associated with PDA and review commonly used neonatal drugs for their vasodilatory properties. Data demonstrating relaxation of the ductus arteriosus by gentamicin and other aminoglycoside antibiotics, by cimetidine and other H2 receptor antagonists, and by heparin are provided as examples of neonatal therapies that have unanticipated effects that may promote PDA.
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Affiliation(s)
- Jeff Reese
- Department of Pediatrics, Monroe Carrell Jr. Children's Hospital at Vanderbilt, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - Alex Veldman
- Monash Newborn and Ritchie Centre for Baby Health Research, Monash Medical Centre and Monash Institute of Medical Research, 246 Clayton Road, Clayton 3168, Melbourne, VIC, Australia
| | - Lisa Shah
- Southern Illinois University School of Medicine, Springfield, IL
| | - Megan Vucovich
- Department of Pediatrics, Vanderbilt University School of Medicine and the Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, TN
| | - Robert B. Cotton
- Department of Pediatrics, Vanderbilt University School of Medicine and the Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, TN
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16
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Toyoshima K, Momma K, Nakanishi T. In vivo dilatation of the ductus arteriosus induced by furosemide in the rat. Pediatr Res 2010; 67:173-6. [PMID: 19809378 DOI: 10.1203/pdr.0b013e3181c2df30] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Furosemide increases prostaglandin production and may be associated with patent ductus arteriosus (PDA). We aimed to clarify the in vivo ductus-dilating effects of furosemide in neonatal rats. Near-term rat pups delivered by a cesarean section were housed at 33 degrees C. After a rapid whole-body freezing, the DA diameter was measured using a microscope and a micrometer. Pregnant rats (gestational day 21) were s.c. injected with furosemide 4 h before delivery, and the neonatal DA was examined 0, 15, 30, 60, and 120 min after birth. Furosemide was also s.c. injected into 60-min-old rats and the DA diameter was examined 30, 60, and 120 min later. The control rats showed a rapid postnatal DA constriction (diameter: 0.80 and 0.08 mm at 0 and 60 min after birth, respectively). Prenatally administered furosemide delayed postnatal DA closure (0.36 mm at 60 min after birth). Furosemide injection in 60-min-old rats dilated the constricted DA at 60 min (0.25 versus 0.02 mm in the controls). Indomethacin inhibited furosemide-induced DA dilatation. Furosemide delays DA closure and dilates the constricted DA in neonatal rats. If furosemide has similar effects in human preterm neonates, caution may be warranted in its use in the treatment of infants with PDA.
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Affiliation(s)
- Katsuaki Toyoshima
- Section of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
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17
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Yamana R, Shirai M, Suzuki T, Tanaka K, Yamamoto M, Arishima K, Takizawa T. Corticosterone synthesis inhibitor-induced decrease in the age-dependant expression of nitric oxide synthase 3 in the preterm ductus arteriosus of rats. J Vet Med Sci 2010; 72:555-60. [PMID: 20057176 DOI: 10.1292/jvms.09-0440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies have shown that the dilating effect of nitric oxide (NO) on the fetal ductus arteriosus (DA) is age dependent and more marked in the premature stages in rats, but the factors that mediate this effect are poorly understood. The purpose of this study is to determine the changes in the expression of NO synthase (NOS) mRNA in the fetal DA and to examine the effect of an 11-beta-hydroxylase inhibitor of corticosterone synthesis, namely, metyrapone, on NOS expression. NOS 3 mRNA expression was observed in 17.5-day-old rat fetuses; thereafter, its level significantly increased and reached its peak on day 19.5 and then decreased until the end of the gestation period (day 21.5). To inhibit corticosterone synthesis, a constant infusion of metyrapone was administered to rats; this significantly decreased the fetal plasma corticosterone concentration as well as NOS 3 mRNA expression in the DA in a time-dependent manner. These results indicate that NO is generated by NOS 3 in the DA and that the age-dependant expression of NOS 3 in the premature DA is attributable to corticosterone-associated activity.
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Affiliation(s)
- Rei Yamana
- Graduate School of Veterinary Medicine, Azabu University, Fuchinobe, Sagamihara, Kanagawa Prefecture, Japan
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18
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Chiruvolu A, Jaleel MA. Pathophysiology of patent ductus arteriosus in premature neonates. Early Hum Dev 2009; 85:143-6. [PMID: 19223128 DOI: 10.1016/j.earlhumdev.2008.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Accepted: 12/11/2008] [Indexed: 11/28/2022]
Abstract
Failure of complete postnatal closure of the ductus arteriosus is associated with various neonatal morbidities. Functional closure resulting from smooth muscle constriction and permanent anatomic closure due to vascular remodeling are the results of a complex interaction of different mechanisms. Prostaglandins, oxygen, nitric oxide and various other factors play a key role in ductal closure. An understanding of the role of these factors, involved both in maintenance of vascular tone of the ductus in fetal life as well as stimulation of ductal closure in postnatal life, and the cardiovascular and respiratory consequences of a patent ductus arteriosus, is important for the clinician involved in management of premature neonates.
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Affiliation(s)
- Arpitha Chiruvolu
- Department of Pediatrics, Division of Neonatology, Baylor University Medical Center, Dallas, Texas 75246, USA.
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19
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Reese J, O'Mara PW, Poole SD, Brown N, Tolentino C, Eckman DM, Aschner JL. Regulation of the fetal mouse ductus arteriosus is dependent on interaction of nitric oxide and COX enzymes in the ductal wall. Prostaglandins Other Lipid Mediat 2008; 88:89-96. [PMID: 19049898 DOI: 10.1016/j.prostaglandins.2008.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Accepted: 11/04/2008] [Indexed: 12/16/2022]
Abstract
Nitric oxide (NO) and cyclooxygenase (COX)-derived prostaglandins are critical regulators of the fetal ductus arteriosus. To examine the interaction of these pathways within the ductus wall, the ductus arteriosus of term and preterm fetal mice was evaluated by pressurized myography. The isolated preterm ductus was more sensitive to NOS inhibition than at term. Sequential NOS and COX inhibition caused 36% constriction of the preterm ductus regardless of drug order. In contrast, constriction of the term ductus was dependent on the sequence of inhibition; NOS inhibition prior to COX inhibition produced greater constriction than when inhibitors were given in reverse order (36+/-6% versus 23+/-5%). Selective COX-1 or COX-2 inhibition prior to N(G)-nitro-l-arginine methyl ester (l-NAME) induced the expected degree of constriction. However, NOS inhibition followed by selective COX-2 inhibition caused unexpected ductal dilation. These findings are consistent with NO-induced activation of COX in the ductus arteriosus wall and the production of a COX-2-derived constrictor prostanoid that contributes to the balance of vasoactive forces that maintain fetal ductus arteriosus tone.
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Affiliation(s)
- Jeff Reese
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232-0656, USA.
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20
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Developmental changes in the effects of prostaglandin E2 in the chicken ductus arteriosus. J Comp Physiol B 2008; 179:133-43. [PMID: 18726601 DOI: 10.1007/s00360-008-0296-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 07/10/2008] [Accepted: 08/03/2008] [Indexed: 10/21/2022]
Abstract
Prostaglandin E(2) (PGE(2)) is the major vasodilator prostanoid of the mammalian ductus arteriosus (DA). In the present study we analyzed the response of isolated DA rings from 15-, 19- and 21-day-old chicken embryos to PGE(2) and other vascular smooth muscle relaxing agents acting through the cyclic AMP signaling pathway. PGE(2) exhibited a relaxant response in the 15-day DA, but not in the 19- and 21-day DA. Moreover, high concentrations of PGE(2) (>or= 3 microM in 15-day and >or= 1 microM in 19-day and 21-day DA) induced contraction of the chicken DA. The presence of the TP receptor antagonist SQ29,548, unmasked a relaxant effect of PGE(2) in the 19- and 21-day DA and increased the relaxation induced by PGE(2) in the 15-day DA. The presence of the EP receptor antagonist AH6809 abolished PGE(2)-mediated relaxation. The relaxant responses induced by PGE(2) and the beta-adrenoceptor agonist isoproterenol, but not those elicited by the adenylate cyclase activator forskolin or the phosphodiesterase 3 inhibitor milrinone, decreased with maturation. High oxygen concentrations (95%) decreased the relaxation to PGE(2). The relaxing potency and efficacy of isoproterenol and milrinone were higher in the pulmonary than in the aortic side of the DA, whereas no regional differences were found in the response to PGE(2). We conclude that, in contrast to the mammalian situation, PGE(2) is a weak relaxant agent of the chicken DA and, with advancing incubation, it even stimulates TP vasoconstrictive receptors.
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21
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Sodini D, Baragatti B, Barogi S, Laubach VE, Coceani F. Indomethacin promotes nitric oxide function in the ductus arteriosus in the mouse. Br J Pharmacol 2008; 153:1631-40. [PMID: 18297107 PMCID: PMC2438253 DOI: 10.1038/bjp.2008.36] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Accepted: 01/15/2008] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Prenatal patency of ductus arteriosus is maintained by prostaglandin (PG) E(2) in concert with nitric oxide (NO) and carbon monoxide (CO). Accordingly, we have previously found that NO activity increases upon deletion of either COX. Here, we have examined whether COX inhibition by indomethacin mimics COX deletion in promoting NO. EXPERIMENTAL APPROACH Experiments were performed in vitro and in vivo with wild-type (WT) and eNOS-/-, near-term mouse foetuses. Indomethacin was given p.o. to the mother as single (acute treatment) or repeated (daily for 3 days; chronic treatment) doses within a therapeutic range (2 mg kg(-1)). KEY RESULTS Indomethacin promoted eNOS mRNA expression in the WT ductus. Coincidentally, the drug enhanced the contraction of the isolated ductus to the NOS inhibitor, N(G)-nitro-L-arginine methyl ester, and its effect augmented with the length of treatment. No such enhancement was seen with the eNOS-/- ductus. Chronic indomethacin also increased, albeit marginally, the contraction of the WT ductus to the CO synthesis inhibitor, zinc protoporphyrin. Whether given acutely or chronically, indomethacin induced a little narrowing of the ductus antenatally and had no effect on postnatal closure of the vessel. CONCLUSIONS AND IMPLICATIONS We conclude that activation of NO and, to a much lesser degree, CO mechanisms is an integral part of the indomethacin effect on the ductus. This relaxing influence may oppose the contraction from PGE(2) suppression and could explain the failures of indomethacin therapy in premature infants with persistent duct.
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Affiliation(s)
- D Sodini
- Scuola Superiore Sant'Anna Pisa, Italy
| | - B Baragatti
- Scuola Superiore Sant'Anna Pisa, Italy
- Institute of Clinical Physiology CNR Pisa, Italy
| | - S Barogi
- Scuola Superiore Sant'Anna Pisa, Italy
- Institute of Clinical Physiology CNR Pisa, Italy
| | - V E Laubach
- Department of Surgery, University of Virginia Health System Charlottesville, VA, USA
| | - F Coceani
- Scuola Superiore Sant'Anna Pisa, Italy
- Institute of Clinical Physiology CNR Pisa, Italy
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22
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Baragatti B, Brizzi F, Barogi S, Laubach VE, Sodini D, Shesely EG, Regan RF, Coceani F. Interactions between NO, CO and an endothelium-derived hyperpolarizing factor (EDHF) in maintaining patency of the ductus arteriosus in the mouse. Br J Pharmacol 2007; 151:54-62. [PMID: 17351656 PMCID: PMC2012984 DOI: 10.1038/sj.bjp.0707211] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Prenatal patency of ductus arteriosus is maintained by prostaglandin (PG) E(2), possibly along with nitric oxide (NO) and carbon monoxide (CO), and cyclooxygenase (COX) deletion upregulates NO. Here, we have examined enzyme source and action of NO for ductus patency and whether NO and CO are upregulated by deletion of, respectively, heme oxygenase 2 (HO-2) and COX1 or COX2. EXPERIMENTAL APPROACH Experiments were performed in vitro and in vivo with wild-type and gene-deleted, near-term mouse fetuses. KEY RESULTS N(G)-nitro-L-arginine methyl ester (L-NAME) contracted the isolated ductus and its effect was reduced by eNOS, but not iNOS, deletion. L-NAME contraction was not modified by HO-2 deletion. Zinc protoporphyrin (ZnPP) also contracted the ductus, an action unaffected by deletion of either COX isoform. Bradykinin (BK) relaxed indomethacin-contracted ductus similarly in wild-type and eNOS-/- or iNOS-/-. BK relaxation was suppressed by either L-NAME or ZnPP. However, it reappeared with combined L-NAME and ZnPP to subside again with K(+) increase or K(+) channel inhibition. In vivo, the ductus was patent in wild-type and NOS-deleted fetuses. Likewise, no genotype-related difference was noted in postnatal closure. CONCLUSIONS AND IMPLICATIONS NO, formed mainly via eNOS, regulates ductal tone. NO and CO cooperatively mediate BK-induced relaxation in the absence of PGE(2). However, in the absence of PGE(2), NO and CO, BK induces a relaxant substance behaving as an endothelium-derived hyperpolarizing factor. Ductus patency is, therefore, sustained by a cohort of agents with PGE(2) and NO being preferentially coupled for reciprocal compensation.
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Affiliation(s)
- B Baragatti
- Scuola Superiore Sant'Anna Pisa, Italy
- Institute of Clinical Physiology CNR Pisa, Italy
| | - F Brizzi
- Scuola Superiore Sant'Anna Pisa, Italy
| | - S Barogi
- Scuola Superiore Sant'Anna Pisa, Italy
- Institute of Clinical Physiology CNR Pisa, Italy
| | - V E Laubach
- Department of Surgery, University of Virginia Health System Charlottesville, VA, USA
| | - D Sodini
- Scuola Superiore Sant'Anna Pisa, Italy
| | - E G Shesely
- Division of Hypertension and Vascular Research, Henry Ford Hospital Detroit, MI, USA
| | - R F Regan
- Department of Emergency Medicine, Thomas Jefferson University Philadelphia, PA, USA
| | - F Coceani
- Scuola Superiore Sant'Anna Pisa, Italy
- Institute of Clinical Physiology CNR Pisa, Italy
- Author for correspondence:
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Toyoshima K, Momma K, Imamura S, Nakanishi T. In vivo dilatation of the postnatal ductus arteriosus by atrial natriuretic peptide in the rat. Neonatology 2007; 92:139-44. [PMID: 17409775 DOI: 10.1159/000101526] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Accepted: 12/18/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND Alpha-human atrial natriuretic peptide (hANP) reportedly increases in premature infants with patent ductus arteriosus (PDA). OBJECTIVES To clarify a possible hANP effect to reopen the postnatal ductus, we studied in vivo reopening of the postnatal DA by a recombinant hANP, carperitide, in rats. METHODS Near-term rat pups were incubated at 33 degrees C following caesarean section. The inner diameter of the ductus was measured with a microscope and a micrometer following rapid whole-body freezing. The DA constricted quickly after birth, and the inner diameter was 0.80 and 0.08 mm at 0 min (fetal state) and 60 min after birth. hANP concentration in the pup blood and the ductus-dilating effect of hANP were studied by subcutaneous injection of hANP at 60 min after birth, and by measurement 7, 15, 30 and 60 min later. RESULTS The peak hANP concentration was 790 pg/ml at 7 min with 1 mg/kg, which is similar to the level seen in preterm infants with symptomatic PDA. hANP dilated the postnatal ductus dose dependently and maximally at 7 min after injection. hANP dilated the postnatal constricted ductus completely to 0.79 mm in diameter with a large dose (10 mg/kg) and to 0.55 mm with 1 mg/kg. CONCLUSIONS hANP reopens the constricted postnatal DA dose dependently in rats. The increased hANP, accompanying premature PDA, may delay closure of the DA.
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Affiliation(s)
- Katsuaki Toyoshima
- Section of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan
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24
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Ly LG, Hawes J, Whyte HE, Teixeira LS, McNamara PJ. The hemodynamically significant ductus arteriosus in critically ill full-term neonates. Two case reports? Neonatology 2007; 91:260-5. [PMID: 17568157 DOI: 10.1159/000098173] [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] [Received: 05/26/2006] [Accepted: 07/28/2006] [Indexed: 11/19/2022]
Abstract
In premature infants, the clinical effects and management of a hemodynamically significant patent ductus arteriosus (HSDA) are well-described. In full-term neonates the ductus arteriosus (DA) is rarely monitored except in cases of concomitant pulmonary hypertension or duct dependent congenital heart disease. Although systemic-pulmonary shunting commonly occurs in mature infants, coinciding with the normal postnatal fall in pulmonary vascular resistance, cardiac failure in the neonatal period is rarely attributed directly to the DA. In this case series, we report two full-term infants who were initially treated for pulmonary hypertension and myocardial dysfunction but developed clinical, radiographic and two-dimensional echocardiographic evidence of cardiac failure secondary to a large unrestrictive patent DA (PDA). One patient was treated with indomethacin, and, although transductal diameter decreased, there was no clinical benefit. Cardiac failure resolved and myocardial function improved in both cases after PDA ligation. We suggest that PDA be monitored closely in neonates recovering from PPHN who have ongoing oxygenation difficulties or myocardial failure. PDA ligation should be considered an option for full term neonates with cardiac failure secondary to a HSDA when other therapeutic options fail.
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Affiliation(s)
- Linh G Ly
- Division of Neonatology, The Hospital for Sick Children, Toronto, Canada
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25
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Takami T, Yoda H, Kawakami T, Yamamura H, Nakanishi T, Nakazawa M, Takei Y, Miyajima T, Hoshika A. Usefulness of indomethacin for patent ductus arteriosus in full-term infants. Pediatr Cardiol 2007; 28:46-50. [PMID: 17203336 DOI: 10.1007/s00246-006-1426-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 08/30/2006] [Indexed: 11/25/2022]
Abstract
The aim of this retrospective study was to evaluate the effectiveness of indomethacin therapy for patent ductus arteriosus (PDA) in full-term infants. The patients were 41 full-term infants with a PDA birth weight (BW) > or =2500 g and a gestational age (GA) > or =37 weeks. The echocardiographic evaluation and medical management of PDA in these infants was similar to that for PDA in low-birth-weight infants. Indomethacin (0.2-0.25 mg/kg/dose) was given intravenously at 12-24-hour intervals within 23 days of birth. Of the 41 infants, 12 showed complete closure, and 13 showed improvement of clinical symptoms. These 25 infants were classified as the responder group (61%). The other 16 infants, who did not show improvement in clinical symptoms, were classified as the nonresponder group. Statistical analysis revealed no difference between the two groups regarding GA, BW, Apgar score at 1 minute, minimum diameter of the DA before treatment, the average age at the initiation of treatment, and DA flow pattern. No severe adverse reactions were observed in any infant. Indomethacin therapy appears to be an effective medical treatment option for PDA in full-term symptomatic infants prior to considering surgical treatment.
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Affiliation(s)
- Takeshi Takami
- Department of Pediatrics, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, 160-0023 Shinjuku-ku, Tokyo, Japan.
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26
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Reese J, Anderson JD, Brown N, Roman C, Clyman RI. Inhibition of cyclooxygenase isoforms in late- but not midgestation decreases contractility of the ductus arteriosus and prevents postnatal closure in mice. Am J Physiol Regul Integr Comp Physiol 2006; 291:R1717-1723. [PMID: 16857891 PMCID: PMC2819844 DOI: 10.1152/ajpregu.00259.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Use of cyclooxygenase (COX) inhibitors to delay preterm birth is complicated by in utero constriction of the ductus arteriosus and delayed postnatal closure. Delayed postnatal closure has been attributed to loss of vasa vasorum flow and ductus wall ischemia resulting from constriction in utero. We used the murine ductus (which does not depend on vasa vasorum flow) to determine whether delayed postnatal closure may be because of mechanisms independent of in utero constriction. Acute inhibition of both COX isoforms constricted the fetal ductus on days 18 and 19 (term) but not earlier in gestation; COX-2 inhibition constricted the fetal ductus more than COX-1 inhibition. In contrast, mice exposed to prolonged inhibition of COX-1, COX-2, or both COX isoforms (starting on day 15, when the ductus does not respond to the inhibitors) had no contractile response to the inhibitors on days 18 or 19. Newborn mice closed their ductus within 4 h of birth. Prolonged COX inhibition on days 11-14 of gestation had no effect on newborn ductal closure; however, prolonged COX inhibition on days 15-19 resulted in delayed ductus closure despite exposure to 80% oxygen after birth. Similarly, targeted deletion of COX-2 alone, or COX-1/COX-2 together, impaired postnatal ductus closure. Nitric oxide inhibition did not prevent the delay in ductus closure. These data show that impaired postnatal ductus closure is not the result of in utero ductus constriction or upregulation of nitric oxide synthesis. They are consistent with a novel role for prostaglandins in ductus arteriosus contractile development.
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Affiliation(s)
- Jeff Reese
- Department of Pediatrics, Vanderbilt University Medical Center, 1125 MRB IV Bldg., 2215 B Garland Avenue, Nashville, TN 37232-0656, USA.
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Abstract
A patent ductus arteriosus (PDA) results in increased pulmonary blood flow and redistribution of flow to other organs. Several co-morbidities (i.e., necrotizing enterocolitis, intracranial hemorrhage, pulmonary edema/hemorrhage, bronchopulmonary dysplasia, and retinopathy) are associated with the presence of a PDA, but whether or not a PDA is responsible for their development is still unclear. In this review, comparative physiology between the full term and preterm newborn and the barriers preventing the necessary cascade of events leading to permanent constriction of the PDA are reviewed.
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Affiliation(s)
- Ronald I Clyman
- School of Medicine, Cardiovascular Research Institute, University of California, San Francisco, Calif., USA.
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Toyoshima K, Takeda A, Imamura S, Nakanishi T, Momma K. Constriction of the ductus arteriosus by selective inhibition of cyclooxygenase-1 and -2 in near-term and preterm fetal rats. Prostaglandins Other Lipid Mediat 2006; 79:34-42. [PMID: 16516808 DOI: 10.1016/j.prostaglandins.2004.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 10/24/2004] [Accepted: 11/19/2004] [Indexed: 11/20/2022]
Abstract
We studied the transplacental ductal constrictive effects of a selective cyclooxygenase (COX)-1 inhibitor (SC560), six selective COX-2 inhibitors including rofecoxib, and a non-selective COX inhibitor (indomethacin). Each drug was administered to the pregnant rats, and fetal ductus arteriosus (DA) was studied with a whole-body freezing method. The inner diameter ratio of the DA to the main pulmonary artery (DA/PA) was 1.02+/-0.03 (mean+/-S.E.M.) in controls. Every drug constricted the DA dose-dependently. In preterm rats on the 19th day of gestation, 10mg/kg of SC560, rofecoxib and indomethacin caused ductal constriction, with DA/PA reduced to 0.76+/-0.02, 0.80+/-0.03 and 0.75+/-0.02, respectively. In near-term on the 21st day, 10mg/kg of them caused ductal constriction, with DA/PA to 0.74+/-0.04, 0.26+/-0.02 and 0.33+/-0.05. In conclusion, both COX-1 and COX-2 selective inhibitors constrict fetal DA. They are not better alternatives for the fetus than non-selective COX inhibitors for tocolysis.
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Affiliation(s)
- Katsuaki Toyoshima
- Department of Pediatric Cardiology, The Heart Institute of Japan, Tokyo Women's Medical University, Tokyo, Japan.
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Keller RL, Tacy TA, Fields S, Ofenstein JP, Aranda JV, Clyman RI. Combined treatment with a nonselective nitric oxide synthase inhibitor (l-NMMA) and indomethacin increases ductus constriction in extremely premature newborns. Pediatr Res 2005; 58:1216-21. [PMID: 16306196 DOI: 10.1203/01.pdr.0000183659.20335.12] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Studies in premature animals suggest that 1) prolonged tight constriction of the ductus arteriosus is necessary for permanent anatomic closure and 2) endogenous nitric oxide (NO) and prostaglandins both play a role in ductus patency. We hypothesized that combination therapy with an NO synthase (NOS) inhibitor [N(G)-monomethyl-L-arginine (L-NMMA)] and indomethacin would produce tighter ductus constriction than indomethacin alone. Therefore, we conducted a phase I and II study of combined treatment with indomethacin and L-NMMA in newborns born at <28 weeks' gestation who had persistent ductus flow by Doppler after an initial three-dose prophylactic indomethacin course (0.2, 0.1, 0.1 mg/kg/24 h). Twelve infants were treated with the combined treatment protocol [three additional indomethacin doses (0.1 mg/kg/24 h) plus a 72-hour L-NMMA infusion]. Thirty-eight newborns received three additional indomethacin doses (without L-NMMA) and served as a comparison group. Ninety-two percent (11/12) of the combined treatment group had tight ductus constriction with elimination of Doppler flow. In contrast, only 42% (16/38) of the comparison group had a similar degree of constriction. L-NMMA infusions were limited in dose and duration by acute side effects. Doses of 10-20 mg/kg/h increased serum creatinine and systemic blood pressure. At 5 mg/kg/h, serum creatinine was stable but systemic hypertension still limited L-NMMA dose. We conclude that combined inhibition of NO and prostaglandin synthesis increased the degree of ductus constriction in newborns born at <28 weeks' gestation. However, the combined administration of L-NMMA and indomethacin was limited by acute side effects in this treatment protocol.
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Affiliation(s)
- Roberta L Keller
- Department of Pediatrics, Cardiovascular Research Institute, Pharmacy, University of California San Francisco, CA 94143, USA.
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Toyoshima K, Momma K, Imamura S, Nakanishi T. In vivo dilatation of the fetal and postnatal ductus arteriosus by inhibition of phosphodiesterase 3 in rats. Neonatology 2005; 89:251-6. [PMID: 16319452 DOI: 10.1159/000089954] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 09/12/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND Clinically, it appears that phosphodiesterase 3 (PDE 3) inhibitors, which are used for acute cardiac failure in premature infants, dilate the ductus arteriosus (DA). OBJECTIVES To clarify the ductus-dilating effects of PDE 3 inhibitors in near-term rat pups and their differential effects in near-term and preterm fetal rats, in in vivo studies. METHODS The in vivo ductal diameter of rat pups and fetuses was measured using a rapid whole-body freezing method, by cutting on a freezing microtome and measuring with a microscope and micrometer. Eight to twenty pups and fetuses were studied in each group. Milrinone and amrinone (specific inhibitors of PDE 3) were injected into 1-hour-old pups and the DA was studied 0.5 and 1 h later. The differential effects of these PDE 3 inhibitors on the near-term and preterm ductus were studied by injecting indomethacin (10 mg/kg) and PDE 3 inhibitors into 21D (21st day of pregnancy: term-21.5 days) and 19D dams and studying the fetal ductus 4 and 8 h later. RESULTS Milrinone and amrinone dilated the postnatal ductus dose-dependently. Large doses of these drugs dilated it completely, and clinically equivalent doses dilated it minimally. Milrinone and amrinone prevented constriction of the fetal ductus by indomethacin. Their ductus-dilating effects were more potent in the preterm than in the near-term fetuses, and clinically equivalent doses of these PDE 3 inhibitors dilated preterm ductus completely. CONCLUSION In rats, PDE 3 inhibitors reopen the constricted postnatal DA slightly. PDE 3 inhibitors dilate the fetal DA constricted with indomethacin effectively and more sensitively in preterm than in near-term fetuses.
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Affiliation(s)
- Katsuaki Toyoshima
- Department of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan.
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Takami T, Momma K, Imamura S. Increased constriction of the ductus arteriosus by dexamethasone, indomethacin, and rofecoxib in fetal rats. Circ J 2005; 69:354-8. [PMID: 15731544 DOI: 10.1253/circj.69.354] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND To find a better treatment for patent ductus arteriosus (PDA) in premature infants, the present study investigated the synergism of clinical doses of dexamethasone, indomethacin, and rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on the fetal ductus arteriosus (DA) in rats. METHODS AND RESULTS Dexamethasone (0.3 mg/kg), indomethacin (0.3 mg/kg), and rofecoxib (0.3 mg/kg), alone or in combination, were administered to preterm (d19) and near-term (d21) fetal rats. The ratio of the inner diameter of the DA to that of the main pulmonary artery (PA) (DA/PA) was studied at 2, 4 and 8 h after drug administration, using a rapid whole-body freezing method. In near-term rats, the combined administration of dexamethasone and indomethacin caused severe constriction, with a DA/PA ratio of 0.52+/-0.08 at 8 h, whereas the DA/PA ratios were 0.83+/-0.03 and 0.90+/-0.02 with dexamethasone and indomethacin, respectively. Combined administration of dexamethasone and rofecoxib also caused severe constriction, with a DA/PA ratio of 0.64+/-0.07 at 8 h, compared with the DA/PA ratio of 0.92+/-0.03 with rofecoxib alone. CONCLUSIONS Combined therapy may be an option in the medical management of PDA in premature infants before considering surgical treatment.
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Affiliation(s)
- Takeshi Takami
- Department of Pediatrics, Tokyo Medical University, Japan.
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Momma K, Toyoshima K, Imamura S, Nakanishi T. In vivo dilation of fetal and neonatal ductus arteriosus by inhibition of phosphodiesterase-5 in rats. Pediatr Res 2005; 58:42-5. [PMID: 15774847 DOI: 10.1203/01.pdr.0000156370.50874.3c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A recent in vitro study showed that sildenafil, a type 5 phosphodiesterase inhibitor, dilated the constricted ductus arteriosus of neonatal rabbits. We studied the in vivo ductus-dilating effects of sildenafil in fetal and neonatal rats. Ductus diameters were measured with whole-body freezing and cutting on a freezing microtome. Indomethacin (10 mg/kg) constricted the fetal ductus severely at 4 and 8 h after orogastric administration to the dams. Sildenafil, administered orogastrically and simultaneously with indomethacin, dilated the near-term fetal [21 fetal days (FD)] ductus constricted by indomethacin completely with 1 mg/kg at 8 h after administration. The preterm fetal ductus was more sensitive to sildenafil at 19FD. The ductus constricted rapidly after birth, and the ductal diameter was only 10% of the fetal diameter at 1 h after birth. The ductus-dilating effect of sildenafil was studied by i.p. injection at 1 h after birth, and the ductus diameter was studied 30 and 60 min later. Sildenafil dilated the neonatal constricted ductus moderately with a massive dose (100 mg/kg) and only minimally with 1 mg/kg. In conclusion, sildenafil, a type 5 phosphodiesterase inhibitor, dilated the constricted fetal ductus completely at 8 h with 1 mg/kg in the near-term fetus and completely with a smaller dose (0.1 mg/kg) in the preterm fetus. However, sildenafil dilated the neonatal constricted ductus only moderately with large doses and minimally with 1 mg/kg. Probably, sildenafil is useful clinically for treating idiopathic and secondary fetal ductal constriction and not useful for dilation of the neonatal constricted ductus.
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Affiliation(s)
- Kazuo Momma
- Department of Pediatric Cardiology, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
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Abstract
The ductus arteriosus is a fetal vessel that allows most of the blood leaving the right ventricle of the heart to bypass the lungs. Fetal patency of the ductus, and its spontaneous closure after birth, is the result of a balanced interaction of locally produced and circulating mediators (of which prostaglandins seem to be the most important), and the unique structure of the vessel wall. Persistent patency of the ductus occurs in almost 60% of very low birthweight infants. A significant left-to-right shunt through the ductus increases morbidity and mortality in premature infants. As prostaglandins play a major role in patency of the ductus, cyclooxygenase inhibitors are conventionally used to induce its closure. This chapter focuses on some of the basic mechanisms underlying ductal patency and the clinical attempts to diminish side effects associated with indomethacin, including the alternative use of ibuprofen.
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Affiliation(s)
- Bart Van Overmeire
- Department of Pediatrics, Neonatal Intensive Care Unit, Antwerp University Hospital, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem, Belgium.
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Coceani F, Barogi S, Brizzi F, Ackerley C, Seidlitz E, Kelsey L, Ballou LR, Baragatti B. Cyclooxygenase isoenzymes and patency of ductus arteriosus. Prostaglandins Leukot Essent Fatty Acids 2005; 72:71-7. [PMID: 15626588 DOI: 10.1016/j.plefa.2004.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Prenatal patency of the ductus arteriosus is maintained mainly by prostaglandin (PG) E(2). Accordingly, the vessel is endowed in its muscular component with a complete, cyclooxygenase (COX) and PGE synthase (PGES), system for the synthesis of the compound. COX1 is better expressed than COX2, particularly in the premature, but COX2 is more extensively coupled with microsomal PGES (mPGES). No evidence was obtained of either COX being coupled with cytosolic PGES (cPGES). Functionally, these data translate into a differential constrictor response of the ductus to dual, COX1/COX2, vs. COX2-specific inhibitors (indomethacin vs. L-745,337), with the latter being less effective specifically prior to term. This difference, however, subsides upon treatment with endotoxin and the attendant upregulation of COX2 and mPGES. Furthermore, when studied separately, COX1 and COX2 prove to be unevenly responsive to indomethacin, and an immediate and fast developing contraction of the vessel occurs only when COX2 is inhibited. Deletion of either COX gene results into upregulation of NO synthase, and a similar compensatory reaction is expected when enzymes are suppressed pharmacologically. We conclude that PGE(2) and NO can function synergistically in keeping the ductus patent. This arrangement provides a possible explanation for failures of indomethacin or ibuprofen treatment in the management of the prematurely born infant with persistent ductus. Coincidentally, it opens the way to new therapeutic possibilities being based on interference with the NO effector or a more selective disruption, possibly having mPGES as a target, of the PGE(2) synthetic cascade.
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Thébaud B, Michelakis ED, Wu XC, Moudgil R, Kuzyk M, Dyck JRB, Harry G, Hashimoto K, Haromy A, Rebeyka I, Archer SL. Oxygen-sensitive Kv channel gene transfer confers oxygen responsiveness to preterm rabbit and remodeled human ductus arteriosus: implications for infants with patent ductus arteriosus. Circulation 2004; 110:1372-9. [PMID: 15353504 DOI: 10.1161/01.cir.0000141292.28616.65] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Oxygen (O2)-sensitive K+ channels mediate acute O2 sensing in many tissues. At birth, initial functional closure of the ductus arteriosus (DA) results from O2-induced vasoconstriction. This mechanism often fails in premature infants, resulting in persistent DA, a common form of congenital heart disease. We hypothesized that the basis for impaired O2 constriction in preterm DA is reduced expression and function of O2-sensitive, voltage-gated (Kv) channels. METHODS AND RESULTS Preterm rabbit DA rings have reduced O2 constriction (even after inhibition of prostaglandin and nitric oxide synthases), and preterm DA smooth muscle cells (DASMCs) display reduced O2-sensitive K+ current. This is associated with decreased mRNA and protein expression of certain O2-sensitive Kv channels (Kv1.5 and Kv2.1) but equivalent expression of the L-type calcium channel. Transmural Kv1.5 or Kv2.1 gene transfer "rescues" the developmental deficiency, conferring O2 responsiveness to preterm rabbit DAs. Targeted SMC Kv1.5 gene transfer also enhances O2 constriction in human DAs. CONCLUSIONS These data demonstrate a central role for developmentally regulated DASMC O2-sensitive Kv channels in the functional closure of the DA. Modulation of Kv channels may have therapeutic potential in diseases associated with impaired O2 responsiveness, including persistent DA.
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Affiliation(s)
- Bernard Thébaud
- Vascular Biology Group, University of Alberta, Edmonton, Alberta, Canada
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Richard C, Gao J, LaFleur B, Christman BW, Anderson J, Brown N, Reese J. Patency of the preterm fetal ductus arteriosus is regulated by endothelial nitric oxide synthase and is independent of vasa vasorum in the mouse. Am J Physiol Regul Integr Comp Physiol 2004; 287:R652-60. [PMID: 15142832 DOI: 10.1152/ajpregu.00049.2004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patency of the fetal ductus arteriosus (DA) is maintained in an environment of low relative oxygen tension and a preponderance of vasodilating forces. In addition to prostaglandins, nitric oxide (NO), a potent vasodilator in the pulmonary and systemic vasculatures, has been implicated in regulation of the fetal DA. To further define the contribution of NO to DA patency, the expression and function of NO synthase (NOS) isoforms were examined in the mouse DA on days 17–19 of pregnancy and after birth. Our results show that endothelial NOS (eNOS) is the predominant isoform expressed in the mouse DA and is localized in the DA endothelium by in situ hybridization. Despite rapid constriction of the DA after birth, eNOS expression levels were unchanged throughout the fetal and postnatal period. Pharmacological inhibition of prostaglandin vs. NO synthesis in vivo showed that the preterm fetal DA on day 16 is more sensitive to NOS inhibition than the mature fetal DA on day 19, whereas prostaglandin inhibition results in marked DA constriction on day 19 but minimal effects on the day 16 DA. Combined prostaglandin and NO inhibition caused additional DA constriction on day 16. The contribution of vasa vasorum to DA regulation was also examined. Immunoreactive platelet endothelial cell adhesion molecule and lacZ tagged FLK1 localized to DA endothelial cells but revealed the absence of vasa vasorum within the DA wall. Similarly, there was no evidence of vasa vasorum by vascular casting. These studies indicate that eNOS is the primary source of NO in the mouse DA and that vasomotor tone of the preterm fetal mouse DA is regulated by eNOS-derived NO and is potentiated by prostaglandins. In contrast to other species, mechanisms for DA patency and closure appear to be independent of any contribution of the vasa vasorum.
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Affiliation(s)
- Charissa Richard
- Department of Pediatrics, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Archer SL, Wu XC, Thébaud B, Moudgil R, Hashimoto K, Michelakis ED. O2 sensing in the human ductus arteriosus: redox-sensitive K+ channels are regulated by mitochondria-derived hydrogen peroxide. Biol Chem 2004; 385:205-16. [PMID: 15134333 DOI: 10.1515/bc.2004.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The ductus arteriosus (DA) is a fetal artery that allows blood ejected from the right ventricle to bypass the pulmonary circulation in utero. At birth, functional closure of the DA is initiated by an O2-induced, vasoconstrictor mechanism which, though modulated by endothelial-derived endothelin and prostaglandins, is intrinsic to the smooth muscle cell (DASMC) [Michelakis et al., Circ. Res. 91 (2002); pp. 478-486]. As pO2 increases, a mitochondrial O2-sensor (electron transport chain complexes I or III) is activated, which generates a diffusible redox mediator (H2O2). H2O2 inhibits voltage-gated K+ channels (Kv) in DASMC. The resulting membrane depolarization activates L-type Ca2+ channels, thereby promoting vasoconstriction. Conversely, inhibiting mitochondrial ETC complexes I or III mimics hypoxia, depolarizing mitochondria, and decreasing H2O2 levels. The resulting increase in K+ current hyperpolarizes the DASMC and relaxes the DA. We have developed two models for study of the DA's O2-sensor pathway, both characterized by decreased O2-constriction and Kv expression: (i) preterm rabbit DA, (ii) ionically-remodeled, human term DA. The O2-sensitive channels Kv1.5 and Kv2.1 are important to DA O2-constriction and overexpression of either channel enhances DA constriction in these models. Understanding this O2-sensing pathway offers therapeutic targets to modulate the tone and patency of human DA in vivo, thereby addressing a common form of congenital heart disease in preterm infants.
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Affiliation(s)
- Stephen L Archer
- Vascular Biology Group, University of Alberta, WMC 2C2.36, 8440 112th Street, Edmonton, Alberta T6G 2B7, Canada.
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Nowicki MJ, Shi D, Cai Z, Bishop PR, May WL. Developmental expression of endothelial nitric oxide synthase (eNOS) in the rat liver. Pediatr Res 2003; 54:732-8. [PMID: 12904594 DOI: 10.1203/01.pdr.0000086904.52847.2a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Transition from fetal to postnatal life requires significant changes in cardiac, pulmonary, and hepatic blood flow. As such, there must be changes in vascular control in these vascular systems. Vascular resistance, a major contributor to blood flow, is mediated in the ductus arteriosus and pulmonary vasculature by endothelial nitric oxide synthase (eNOS). This study was conducted to determine the ontogeny of hepatic eNOS expression and activity. Additionally, the expression and activity of inducible nitric oxide synthase (iNOS) was measured to determine whether perinatal hypoxia resulted in detectable levels. NOS mRNA and proteins were determined by reverse transcription PCR assay and semiquantitative Western blot analysis, respectively. NOS activity was measured by the formation of [14C]-citrulline from [14C]-arginine. Localization of eNOS within the liver was determined by immunohistochemistry. eNOS mRNA was detectable at low levels at 18-d gestation and increased after birth, reaching a maximum level (4.5-fold increase) at 20 d of life. Parallel patterns for eNOS protein and activity were seen, with 6.9-fold and 16.1-fold increases, respectively. In the prenatal rat, eNOS was localized to areas of extramedullary hematopoiesis, with little signal in the sinusoids. Postnatally, there was a decrease in staining in the hematopoietic cells and a gradual increase in the staining of the endothelium of the sinusoids and central veins. iNOS mRNA and protein could not be detected at any age. eNOS expression and activity are developmentally regulated, increasing after birth coincident with an initial relative hypoxia and an increase in shear forces upon closure of the ductus venosus.
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Affiliation(s)
- Michael J Nowicki
- Division of Pediatric Gastroenterology, University of Mississippi Medical Center, Jackson, MS 39216, USA.
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Baragatti B, Brizzi F, Ackerley C, Barogi S, Ballou LR, Coceani F. Cyclooxygenase-1 and cyclooxygenase-2 in the mouse ductus arteriosus: individual activity and functional coupling with nitric oxide synthase. Br J Pharmacol 2003; 139:1505-15. [PMID: 12922938 PMCID: PMC1573985 DOI: 10.1038/sj.bjp.0705391] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2003] [Revised: 05/19/2003] [Accepted: 05/20/2003] [Indexed: 11/09/2022] Open
Abstract
1. Prenatal patency of the ductus arteriosus is maintained by prostaglandin (PG) E(2), conceivably in concert with nitric oxide (NO). Local PGE(2) formation is sustained by cyclooxygenase-1 (COX1) and cyclooxygenase-2 (COX2), a possible exception being the mouse in which COX1, or both COXs, are reportedly absent. Here, we have examined the occurrence of functional COX isoforms in the near-term mouse ductus and the possibility of COX deletion causing NO upregulation. 2. COX1 and COX2 were detected in smooth muscle cells by immunogold electronmicroscopy, both being located primarily in the perinuclear region. Cytosolic and microsomal PGE synthases (cPGES and mPGES) were also found, but they occurred diffusely across the cytosol. COX1 and, far more frequently, COX2 were colocalised with mPGES, while neither COX appeared to be colocalized with cPGES. 3. The isolated ductus from wild-type and COX1-/- mice contracted promptly to indomethacin (2.8 micro M). Conversely, the contraction of COX2-/- ductus to the same inhibitor started only after a delay and was slower. 4. N(G)-nitro-L-arginine methyl ester (L-NAME, 100 micro M) weakly contracted the isolated wild-type ductus. Its effect, however, increased three- to four-fold after deleting either COX, hence equalling that of indomethacin. 5. In vivo, the ductus was patent in all mice foetuses, whether wild-type or COX-deleted. Likewise, no genotype-related difference was noted in its postnatal closure. 6. We conclude that the mouse ductus has a complete system for PGE(2) synthesis comprising both COX1 and COX2. The two enzymes respond differently to indomethacin but, nevertheless, deletion of either one results in NO upregulation. PGE(2) and NO can function synergistically in keeping the ductus patent.
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Affiliation(s)
- B Baragatti
- Institute of Clinical Physiology CNR, 56127 Pisa, Italy
| | - F Brizzi
- Scuola Superiore S. Anna, 56127 Pisa, Italy
| | - C Ackerley
- Department of Pathology, Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8
| | - S Barogi
- Institute of Clinical Physiology CNR, 56127 Pisa, Italy
| | - L R Ballou
- Departments of Medicine and Molecular Sciences, University of Tennessee/Department of Veterans Affairs, Memphis, TN 38104, U.S.A
| | - F Coceani
- Institute of Clinical Physiology CNR, 56127 Pisa, Italy
- Scuola Superiore S. Anna, 56127 Pisa, Italy
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Momma K, Nakanishi T, Imamura S. Inhibition of in vivo constriction of fetal ductus arteriosus by endothelin receptor blockade in rats. Pediatr Res 2003; 53:479-85. [PMID: 12595598 DOI: 10.1203/01.pdr.0000049516.70216.2e] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The fetal ductus can be constricted by drugs, including cyclooxygenase inhibitors (indomethacin), nitric oxide synthesis antagonists [N-nitro-L-arginine monomethyl ester (L-NAME)], and glucocorticoid hormones (dexamethasone). Constriction of the fetal ductus by endothelin (ET) 1 was reported in an in vitro study. We studied the preventive effect of a dual ET receptor antagonist (bosentan) and a selective ET-A blocker (CI-1020) on pharmacologic fetal ductal constriction in rats. Near-term pregnant Wistar rats at d 21 and preterm rats at d 19 were used. The fetal ductus was constricted by four medications: orogastric administration of indomethacin (10 mg/kg) on fetal d 21, orogastric indomethacin 1 mg/kg combined with muscular injection of L-NAME (10 mg/kg) on fetal d 21, and muscular injection of L-NAME or dexamethasone (1 mg/kg) on fetal d 19. Bosentan (0.1, 1, 10, or 100 mg/kg) was injected intraperitoneally either simultaneously with indomethacin, L-NAME, or dexamethasone, or 4 h after administration of 10 mg/kg indomethacin. CI-1020 (0.01, 0.1, 1, or 10 mg/kg) was injected intraperitoneally simultaneously with indomethacin. After maternal atlas dislocation, cesarean section, fetal whole-body freezing, and cutting on the freezing microtome, measurements were made of the inner diameters of the ductus, main pulmonary artery, and ascending aorta. Bosentan blocked fetal ductal constriction by indomethacin, indomethacin plus L-NAME in the near-term rats, and constriction by L-NAME and dexamethasone in the preterm rats dose dependently. Fetal ductal constriction was nearly completely blocked by simultaneously administered 100 mg/kg of bosentan or 10 mg/kg of CI-1020. Dual ET receptor antagonist (bosentan) and selective ET-A blocker (CI-1020) prevent constriction of the fetal ductus arteriosus induced by ductus-constricting agents in rats, indicating that ET and ET-A receptors are essential in fetal ductal constriction.
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Affiliation(s)
- Kazuo Momma
- Department of Pediatric Cardiology, The Heart Institute of Japan, Tokyo Women's Medical University, Tokyo, Japan.
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Coceani F, Kelsey L, Seidlitz E. The response of the lamb ductus arteriosus to endothelin: developmental changes and influence of light. Life Sci 2002; 71:1209-17. [PMID: 12095541 DOI: 10.1016/s0024-3205(02)01822-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Endothelin-1 (ET-1) is a putative messenger of oxygen in the ductus arteriosus. Since the ability of the vessel to contract to oxygen increases with gestation, we wished to ascertain whether ET-1 action is also developmentally regulated. A corollary objective was to assess whether any gestational variation in the ET-1 contraction is due to a change in the ET(A)-mediated action or to a shift in the balance between opposing, contractile (ET(A) - mediated) and relaxant (ET(B)-mediated), actions. Experiments were performed with isolated ductal strips from preterm (0.7 gestation) and near-term fetal lambs. ET-1 contracted the ductus dose-dependently (10(-10)-10(-7) M) at both ages; however, the peak contraction was about double in magnitude at term. Regardless of age, ET-1 contraction was greater with preparations kept in the dark compared to those exposed to light. This effect of light was not seen after removing the endothelium or when treating the intact tissue with the ET(B) antagonist BQ788 (1 microM). In the dark, however, BQ788 did not modify significantly the ET-1 response at either age. We conclude that ET-1 becomes a stronger ductus constrictor with fetal age, conceivably by acting on ET(A) receptors. Hence, the concept of ET-1 mediating the oxygen contraction is further validated. Peculiarly, the ET-1 contraction is curtailed by light through a hitherto undefined ET(B) receptor-linked process.
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Affiliation(s)
- Flavio Coceani
- Integrative Biology Programme, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.
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Seidner SR, Chen YQ, Oprysko PR, Mauray F, Tse MM, Lin E, Koch C, Clyman RI. Combined prostaglandin and nitric oxide inhibition produces anatomic remodeling and closure of the ductus arteriosus in the premature newborn baboon. Pediatr Res 2001; 50:365-73. [PMID: 11518824 DOI: 10.1203/00006450-200109000-00012] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
After birth, the full-term ductus arteriosus actively constricts and undergoes extensive histologic changes that prevent subsequent reopening. These changes are thought to occur only if a region of intense hypoxia develops within the ductus wall after the initial active constriction. In preterm infants, indomethacin-induced constriction of the ductus is often transient and is followed by reopening. Prostaglandins and nitric oxide both play a role in inhibiting ductus closure in vitro. We hypothesized that combined inhibition of both prostaglandin and nitric oxide production (with indomethacin and N-nitro-L-arginine (L-NA), respectively) may be required to produce the degree of functional closure that is needed to cause intense hypoxia. We used preterm (0.67 gestation) newborn baboons that were mechanically ventilated for 6 d: 6 received indomethacin alone, 7 received indomethacin plus L-NA, and 16 received no treatment (control). Just before necropsy, only 25% of control ductus and 33% of indomethacin-treated ductus were closed on Doppler examination; in contrast, 100% of the indomethacin-plus-L-NA-treated ductus were closed. Control and indomethacin-treated baboons developed negligible-to-mild ductus hypoxia (EF5 technique). Similarly, there was minimal evidence of ductus remodeling. In contrast, indomethacin-plus-L-NA-treated baboons developed intense hypoxia in regions where the ductus was most constricted. The hypoxic muscle strongly expressed vascular endothelial growth factor, and proliferating luminal endothelial cells filled and occluded the lumen. In addition, cells in the most hypoxic regions were undergoing DNA fragmentation. In conclusion, preterm newborns are capable of remodeling their ductus, just like the full-term newborn, if they can reduce their luminal blood flow to a point that produces intense ductus wall hypoxia. Combined prostaglandin and nitric oxide inhibition may be necessary to produce permanent closure of the ductus and prevent reopening in preterm infants.
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Affiliation(s)
- S R Seidner
- Cardiovascular Research Institute, University of California San Francisco, CA 94143-0544, USA
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Kajino H, Chen YQ, Seidner SR, Waleh N, Mauray F, Roman C, Chemtob S, Koch CJ, Clyman RI. Factors that increase the contractile tone of the ductus arteriosus also regulate its anatomic remodeling. Am J Physiol Regul Integr Comp Physiol 2001; 281:R291-301. [PMID: 11404305 DOI: 10.1152/ajpregu.2001.281.1.r291] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Permanent closure of the full-term newborn ductus arteriosus (DA) occurs only if profound hypoxia develops within the vessel wall during luminal obliteration. We used fetal and newborn baboons and lambs to determine why the immature DA fails to remodel after birth. When preterm newborns were kept in a normoxic range (Pa(O(2)): 50-90 mmHg), 86% still had a small patent DA on the sixth day after birth; in addition, the preterm DA wall was only mildly hypoxic and had only minimal remodeling. The postnatal increase in Pa(O(2)) normally induces isometric contractile responses in rings of DA; however, the excessive inhibitory effects of endogenous prostaglandins and nitric oxide, coupled with a weaker intrinsic DA tone, make the preterm DA appear to have a smaller increment in tension in response to oxygen than the DA near term. We found that oxygen concentrations, beyond the normoxic range, produce an additional increase in tension in the preterm DA that is similar to the contractile response normally seen at term. We predicted that preterm newborns, kept at a higher Pa(O(2)), would have increased DA tone and would be more likely to obliterate their lumen. We found that preterm newborns, maintained at a Pa(O(2)) >200 mmHg, had only a 14% incidence of patent DA. Even though DA constriction was due to elevated Pa(O(2)), obliteration of the lumen produced profound hypoxia of the DA wall and the same features of remodeling that were observed at term. DA wall hypoxia appears to be both necessary and sufficient to produce anatomic remodeling in preterm newborns.
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Affiliation(s)
- H Kajino
- Cardiovascular Research Institute, University of California, San Francisco 94143-0544, California, USA
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Segi E. [A study for functions of prostaglandin E receptor EP4 subtype by analysing knockout mice]. YAKUGAKU ZASSHI 2001; 121:35-45. [PMID: 11201161 DOI: 10.1248/yakushi.121.35] [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: 11/22/2022]
Abstract
The physiological role of the prostaglandin (PG) E2 receptor EP4 subtype was investigated by the generation of EP4-deficient mice by gene targeting. Loss of the EP4 receptor was not lethal in utero, but most EP4 (-/-) neonates became pale and lethargic approximately 24 h after birth, and died within 72 h. Less than 5% of the EP4 (-/-) mice survived and grew normally more than a year. Marked congestion in the pulmonary capillaries were observed before death, suggesting that EP4 (-/-) neonates had left-sided heart failure. Histological examination revealed that the ductus arteriosus in dead neonates remained open, while it was partially closed in the survivors. In situ hybridization study showed that EP4 mRNA was strongly expressed in the ductus. The treatment of indomethacin, an inhibitor of PG synthesis, on wild-type fetus induced constriction of ductus arteriosus, while the ductus in EP4 (-/-) fetus was insensitive to indomethacin. These results suggest that neonatal death is at least partly due to patent ductus arteriosus, and that the EP4 receptor plays a role in the regulation of the patency of this vessel. They also indicate that the normal function of the EP4 receptor is essential in neonatal adaptation of the circulatory system.
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Affiliation(s)
- E Segi
- Faculty of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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Takizawa T, Kihara T, Kamata A, Yamamoto M, Arishima K. Role of nitric oxide in regulating the ductus arteriosus caliber in fetal rats. J Vet Med Sci 2000; 62:707-10. [PMID: 10945287 DOI: 10.1292/jvms.62.707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of nitric oxide (NO) on the ductus arteriosus (DA) patency was examined in fetal rats at various stages of gestation. N(G)-nitro-L-arginine methyl ester (L-NAME, 50 mg/kg, i.p.), an NO synthase (NOS) inhibitor, or indomethacin (3 mg/kg, p.o.), a cyclooxygenase inhibitor, was administered at 3 hr before cesarean section to pregnant rats ranging from day 17 to day 21 of gestation. Dams were decapitated and the fetuses were obtained by cesarean section. The fetuses were rapidly frozen in an acetone-dry ice mixture. Using rapid-freezing and shaving methods, the calibers of the DA and pulmonary artery were measured. The constrictive effect of L-NAME on the fetal DA caliber was stronger than that of indomethacin in 19-day-old and immature fetuses. In near-term fetuses, the constrictive effects of L-NAME were reduced, while indomethacin caused marked DA constriction. We conclude that endogenous NO may play a major role in regulating the patency of the DA in earlier fetal stages, while dilator prostaglandins may play a greater role in regulating the ductal patency in the near-term fetus.
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Affiliation(s)
- T Takizawa
- Department of Developmental Biotechnology, Azabu University School of Veterinary Medicine, Kanagawa, Japan
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