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Bechmann N, Westermann F, Eisenhofer G. HIF and MYC signaling in adrenal neoplasms of the neural crest: implications for pediatrics. Front Endocrinol (Lausanne) 2023; 14:1022192. [PMID: 37361539 PMCID: PMC10286580 DOI: 10.3389/fendo.2023.1022192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 05/09/2023] [Indexed: 06/28/2023] Open
Abstract
Pediatric neural crest-derived adrenal neoplasms include neuroblastoma and pheochromocytoma. Both entities are associated with a high degree of clinical heterogeneity, varying from spontaneous regression to malignant disease with poor outcome. Increased expression and stabilization of HIF2α appears to contribute to a more aggressive and undifferentiated phenotype in both adrenal neoplasms, whereas MYCN amplification is a valuable prognostic marker in neuroblastoma. The present review focuses on HIF- and MYC signaling in both neoplasms and discusses the interaction of associated pathways during neural crest and adrenal development as well as potential consequences on tumorigenesis. Emerging single-cell methods together with epigenetic and transcriptomic analyses provide further insights into the importance of a tight regulation of HIF and MYC signaling pathways during adrenal development and tumorigenesis. In this context, increased attention to HIF-MYC/MAX interactions may also provide new therapeutic options for these pediatric adrenal neoplasms.
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Affiliation(s)
- Nicole Bechmann
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Frank Westermann
- Hopp Children’s Cancer Center Heidelberg (KiTZ), Heidelberg, Germany
- Division of Neuroblastoma Genomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Graeme Eisenhofer
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Department of Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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2
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Horackova H, Vachalova V, Abad C, Karahoda R, Staud F. Perfused rat term placenta as a preclinical model to investigate placental dopamine and norepinephrine transport. Clin Sci (Lond) 2023; 137:149-161. [PMID: 36598165 DOI: 10.1042/cs20220726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/22/2022] [Accepted: 01/04/2023] [Indexed: 01/05/2023]
Abstract
The placenta represents a non-neuronal organ capable of transporting and metabolizing monoamines. Since these bioactive molecules participate in numerous processes essential for placental and fetal physiology, any imbalance in their levels during pregnancy may affect brain development, projecting a higher risk of behavioral disorders in childhood or adulthood. Notably, the monoamine system in the placenta is a target of various psychoactive drugs and can be disrupted in several pregnancy pathologies. As research in pregnant women poses significant ethical restrictions, animal models are widely employed to study monoamine homeostasis as a mechanism involved in fetal programming. However, detailed knowledge of monoamine transport in the rat placenta is still lacking. Moreover, relatability to the human placental monoamine system is not examined. The present study provides insights into the transplacental monoamine dynamics between maternal and fetal circulation. We show that norepinephrine maternal-to-fetal transport is <4% due to high metabolism within the trophoblast. In contrast, dopamine maternal-to-fetal transport exceeds 25%, likely through passive transport across the membrane. In addition, we show high clearance of norepinephrine and dopamine from the fetal circulation mediated by the organic cation transporter 3 (OCT3). Altogether, we present transcriptional and functional evidence that the in situ rat placenta perfusion represents a suitable model for (patho)physiological investigation of dopamine and norepinephrine homeostasis in the fetoplacental unit. With the rapid advancements in drug discovery and environmental toxicity, the use of rat placenta as a preclinical model could facilitate screening of possible xenobiotic effects on monoamine homeostasis in the placenta.
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Affiliation(s)
- Hana Horackova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Czech Republic
| | - Veronika Vachalova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Czech Republic
| | - Cilia Abad
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Czech Republic
| | - Rona Karahoda
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Czech Republic
| | - Frantisek Staud
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Czech Republic
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Functional characterization of dopamine and norepinephrine transport across the apical and basal plasma membranes of the human placental syncytiotrophoblast. Sci Rep 2022; 12:11603. [PMID: 35804076 PMCID: PMC9270497 DOI: 10.1038/s41598-022-15790-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/29/2022] [Indexed: 11/23/2022] Open
Abstract
The human placenta represents a unique non-neuronal site of monoamine transporter expression, with pathophysiological relevance during the prenatal period. Monoamines (serotonin, dopamine, norepinephrine) are crucial neuromodulators for proper placenta functions and fetal development, including cell proliferation, differentiation, and neuronal migration. Accumulating evidence suggests that even a transient disruption of monoamine balance during gestation may lead to permanent changes in the fetal brain structures and functions, projecting into adulthood. Nonetheless, little is known about the transfer of dopamine and norepinephrine across the placental syncytiotrophoblast. Employing the method of isolated membranes from the human term placenta, here we delineate the transport mechanisms involved in dopamine and norepinephrine passage across the apical microvillous (MVM) and basal membranes. We show that the placental uptake of dopamine and norepinephrine across the mother-facing MVM is mediated via the high-affinity and low-capacity serotonin (SERT/SLC6A4) and norepinephrine (NET/SLC6A2) transporters. In the fetus-facing basal membrane, however, the placental uptake of both monoamines is controlled by the organic cation transporter 3 (OCT3/SLC22A3). Our findings thus provide insights into physiological aspects of dopamine and norepinephrine transport across both the maternal and fetal sides of the placenta. As monoamine transporters represent targets for several neuroactive drugs such as antidepressants, our findings are pharmacologically relevant to ensure the safety of drug use during pregnancy.
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4
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Abstract
Successful outcome of pregnancy depends upon genetic, cellular, and hormonal interactions, which lead to implantation, placentation, embryonic, and fetal development, parturition and fetal adaptation to extrauterine life. The fetal endocrine system commences development early in gestation and plays a modulating role on the various physiological organ systems and prepares the fetus for life after birth. Our current article provides an overview of the current knowledge of several aspects of this vast field of fetal endocrinology and the role of endocrine system on transition to extrauterine life. We also provide an insight into fetal endocrine adaptations pertinent to various clinically important situations like placental insufficiency and maternal malnutrition.
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Affiliation(s)
- Sunil Kumar Kota
- Department of Endocrinology, Medwin Hospital, Hyderabad, Andhra Pradesh, India
| | - Kotni Gayatri
- Department of Obstetrics and Gynecology, Riyadh Care Hospital, Riyadh, Saudi Arabia
| | - Sruti Jammula
- Department of Pharmaceutics, Roland Institute of Pharmaceutical Sciences, Berhampur, Orissa, India
| | - Lalit Kumar Meher
- Department of Medicine, MKCG Medical College, Berhampur, Orissa, India
| | - Siva Krishna Kota
- Department of Anesthesia, Central Security Hospital, Riyadh, Saudi Arabia
| | - S. V. S. Krishna
- Department of Endocrinology, Medwin Hospital, Hyderabad, Andhra Pradesh, India
| | - Kirtikumar D. Modi
- Department of Endocrinology, Medwin Hospital, Hyderabad, Andhra Pradesh, India
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5
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Wang CC, Billett E, Borchert A, Kuhn H, Ufer C. Monoamine oxidases in development. Cell Mol Life Sci 2013; 70:599-630. [PMID: 22782111 PMCID: PMC11113580 DOI: 10.1007/s00018-012-1065-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/13/2012] [Accepted: 06/19/2012] [Indexed: 12/29/2022]
Abstract
Monoamine oxidases (MAOs) are flavoproteins of the outer mitochondrial membrane that catalyze the oxidative deamination of biogenic and xenobiotic amines. In mammals there are two isoforms (MAO-A and MAO-B) that can be distinguished on the basis of their substrate specificity and their sensitivity towards specific inhibitors. Both isoforms are expressed in most tissues, but their expression in the central nervous system and their ability to metabolize monoaminergic neurotransmitters have focused MAO research on the functionality of the mature brain. MAO activities have been related to neurodegenerative diseases as well as to neurological and psychiatric disorders. More recently evidence has been accumulating indicating that MAO isoforms are expressed not only in adult mammals, but also before birth, and that defective MAO expression induces developmental abnormalities in particular of the brain. This review is aimed at summarizing and critically evaluating the new findings on the developmental functions of MAO isoforms during embryogenesis.
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Affiliation(s)
- Chi Chiu Wang
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Shatin, Hong Kong
- Li Ka Shing Institute of Health Sciences, Shatin, Hong Kong
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Ellen Billett
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS UK
| | - Astrid Borchert
- Institute of Biochemistry, University Medicine Berlin-Charité, Oudenarder Str. 16, 13347 Berlin, Germany
| | - Hartmut Kuhn
- Institute of Biochemistry, University Medicine Berlin-Charité, Oudenarder Str. 16, 13347 Berlin, Germany
| | - Christoph Ufer
- Institute of Biochemistry, University Medicine Berlin-Charité, Oudenarder Str. 16, 13347 Berlin, Germany
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Richter S, Qin N, Pacak K, Eisenhofer G. Role of hypoxia and HIF2α in development of the sympathoadrenal cell lineage and chromaffin cell tumors with distinct catecholamine phenotypic features. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2013; 68:285-317. [PMID: 24054150 PMCID: PMC3785008 DOI: 10.1016/b978-0-12-411512-5.00014-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hypoxia has wide-ranging impact in normal physiology and disease processes. This stimulus evokes changes in gene expression mediated by transcription factors termed hypoxia-inducible factors (HIFs) that affect numerous processes: angiogenesis, cell survival, cellular metabolism, stem cell self-renewal and multipotency, migration, invasiveness, and metastatic progression in tumor cells. Over the past decade, increasing numbers of reports have emerged documenting differential roles of HIF1α and HIF2α in these processes. In cells of the sympathoadrenal lineage, both HIFs differentially mediate influences of hypoxia on catecholamine synthesis and secretion, but HIF2α signaling has particularly prominent functions in regulating developmental processes of growth and differentiation. This chapter discusses the role of HIF2α and HIF1α in the context of the development, phenotypic features, and functions of chromaffin cells. Moreover, current knowledge about tumor formation in cells of the sympathoadrenal lineage, leading to catecholamine-producing pheochromocytomas and paragangliomas, is analyzed in the light of the HIF2α signaling network.
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Affiliation(s)
- Susan Richter
- Department of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus Dresden, Dresden University of Technology, Dresden, Germany.
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7
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Pfeiffer S, Boyle J, Daly S, Dowd E, Haase J, McLaughlin D. Human amniocytes regulate serotonin levels by active uptake and express genes suggestive of a wider role in facilitating neurotransmitter regulation in the fetal environment. Stem Cells Dev 2010; 20:341-9. [PMID: 20528162 DOI: 10.1089/scd.2009.0500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Fetal serotonin levels, which mediate multiple developmental processes, are highly regulated. However, an incomplete picture exists on the component parts of such regulation during fetal growth. Serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) are found in the amniotic fluid, also containing significant numbers of amniocytes, previously thought to be the result of cell shedding as a byproduct of growth. The aim of the present study was to examine human amniocytes as a potentially active and dynamic component of serotonin regulation in the fetal environment. Using amniocytes derived from multiple donors of amniocentesis, we found all components necessary for serotonin metabolism. We identified a strong expression of the serotonin transporter and confirmed the high-affinity serotonin transporter-mediated uptake of serotonin (5-HT), along with uptake via the norepinephrine transporter, and an evidence of 5-HT breakdown due to the expression of the degradative enzymes monoamine oxidase A and B. Additionally, wider expression analysis for biogenic amine and cholinergic metabolism suggests a capability for cholinergic synthesis and release and for catecholamine storage. Our results shed new light on amniocytes, consistent with a role in the homeostasis of neurotransmitters during fetal development. Moreover, these results may provide clinical significance for amniocytes as new targets for uptake inhibitors such as tricyclic antidepressants, selective serotonin reuptake inhibitors, and drugs of abuse such as cocaine, with implications on their regulation during pregnancy. This work shows for the first time an inherent in vivo function of amniocytes and more broadly implicates them as a new and active component of the fetal-maternal regulatory system.
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Affiliation(s)
- Shona Pfeiffer
- Laboratory of Developmental Neurobiology, School of Biomolecular and Biomedical Sciences, University College Dublin, Conway Institute, Dublin, Ireland
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Abstract
Continuing advances in the care of premature infants has contributed to the increased survival of very low birth weight premature infants. These infants are characterized by a variety of organ and physiological systems immaturities predisposing to deficiencies of postnatal adaptation and a high prevalence of neonatal morbidities. These morbidities have a major impact on postnatal mental and neurological outcomes. Thyroid hormones play a critical role in central nervous system development and function, and thyroid system immaturities as well as morbidity-related thyroid dysfunction (the nonthyroidal illness syndrome) contribute to the transient hypothyroxinemia of premature infants (THOP). Several studies have demonstrated a correlation of THOP with subsequent low IQ and neurologic sequelae in very low birth weight premature infants, and there is suggestive evidence that thyroid hormone supplementation in very low birth weight infants can improve mental outcome. Here, we review normal fetal thyroid system development and the system immaturities contributing to THOP and predisposing to nonthyroidal illness in very low birth weight infants.
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Jögi A, Øra I, Nilsson H, Lindeheim A, Makino Y, Poellinger L, Axelson H, Påhlman S. Hypoxia alters gene expression in human neuroblastoma cells toward an immature and neural crest-like phenotype. Proc Natl Acad Sci U S A 2002; 99:7021-6. [PMID: 12011461 PMCID: PMC124521 DOI: 10.1073/pnas.102660199] [Citation(s) in RCA: 301] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Insufficient oxygen and nutrient supply often restrain solid tumor growth, and the hypoxia-inducible factors (HIF) 1 alpha and HIF-2 alpha are key transcription regulators of phenotypic adaptation to low oxygen levels. Moreover, mouse gene disruption studies have implicated HIF-2 alpha in embryonic regulation of tyrosine hydroxylase, a hallmark gene of the sympathetic nervous system. Neuroblastoma tumors originate from immature sympathetic cells, and therefore we investigated the effect of hypoxia on the differentiation status of human neuroblastoma cells. Hypoxia stabilized HIF-1 alpha and HIF-2 alpha proteins and activated the expression of known hypoxia-induced genes, such as vascular endothelial growth factor and tyrosine hydroxylase. These changes in gene expression also occurred in hypoxic regions of experimental neuroblastoma xenografts grown in mice. In contrast, hypoxia decreased the expression of several neuronal/neuroendocrine marker genes but induced genes expressed in neural crest sympathetic progenitors, for instance c-kit and Notch-1. Thus, hypoxia apparently causes dedifferentiation both in vitro and in vivo. These findings suggest a novel mechanism for selection of highly malignant tumor cells with stem-cell characteristics.
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Affiliation(s)
- Annika Jögi
- Department of Laboratory Medicine, Division of Molecular Medicine, Lund University, University Hospital MAS, S-205 02 Malmö, Sweden
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10
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Mulder AL, Golde JM, Goor AA, Giussani DA, Blanco CE. Developmental changes in plasma catecholamine concentrations during normoxia and acute hypoxia in the chick embryo. J Physiol 2000; 527 Pt 3:593-9. [PMID: 10990543 PMCID: PMC2270098 DOI: 10.1111/j.1469-7793.2000.00593.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
In the mammalian fetus, the cardiovascular responses to acute hypoxaemia include a redistribution of the cardiac output away from the periphery towards the adrenal, myocardial and cerebral circulations. A component of the peripheral vasoconstriction is mediated by increased release of catecholamines into the fetal circulation during acute hypoxaemia. Previously, we have shown that the chick embryo also shows an increase in peripheral vascular resistance during acute hypoxaemia and that this response becomes progressively larger towards the end of the incubation period. However, the ontogeny of the catecholaminergic response to acute hypoxaemia has not been investigated in this species. Fertilised chicken eggs were studied on days 10, 13, 16 and 19 of incubation (hatching is at 21 days). At each stage of incubation, blood samples were obtained from the chorioallantoic artery of the chick embryos during normoxia and after 5 min of hypoxaemia for measurement of plasma concentrations of adrenaline and noradrenaline by HPLC. Basal plasma adrenaline and noradrenaline concentrations by the end of the incubation period were much higher in the chick embryo than values reported for mammalian fetuses during late gestation. During normoxia, basal plasma noradrenaline concentration remained unchanged during development but plasma adrenaline concentration showed a developmental increase from < 25.1 pmol l-1 at day 10 to 3 nmol l-1 at day 19 of incubation. Acute hypoxaemia caused an increase in plasma noradrenaline and adrenaline from day 13 and day 16 of incubation, respectively. In addition, the increase in plasma adrenaline and noradrenaline and in the ratio of plasma adrenaline to noradrenaline during acute hypoxaemia became progressively larger by the end of the incubation period. These data show an ontogenic increase in basal plasma catecholamines and in the catecholaminergic response to acute hypoxaemia in the chick embryo during the last third of the incubation period.
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Affiliation(s)
- A L Mulder
- Department of Paediatrics, University Hospital Maastricht and Research Institute GROW, Maastricht University, Maastricht, The Netherlands.
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Ganapathy V, Prasad PD, Ganapathy ME, Leibach FH. Drugs of abuse and placental transport. Adv Drug Deliv Rev 1999; 38:99-110. [PMID: 10837749 DOI: 10.1016/s0169-409x(99)00009-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The placenta provides the only link between the mother and the developing fetus. The function of the placenta as a transport organ is obligatory for fetal development because this process, mediated by a variety of transport systems, is responsible for the delivery of nutrients from the mother to the fetus. Some of the transport systems in the placenta also play a role in the clearance of vasoactive compounds, thus maintaining optimal blood flow to this organ. There is strong supporting evidence to indicate that several of these placental transport systems are either direct or indirect targets for the abusable drugs cocaine, amphetamines, nicotine, and cannabinoids. These drugs of abuse compromise the placental transport function and consequently produce detrimental effects on the developing fetus.
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Affiliation(s)
- V Ganapathy
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta, GA, USA
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Kallio J, Karlsson R, Toppari J, Helminen T, Scheinin M, Kero P. Antenatal dexamethasone treatment decreases plasma catecholamine levels in preterm infants. Pediatr Res 1998; 43:801-7. [PMID: 9621991 DOI: 10.1203/00006450-199806000-00014] [Citation(s) in RCA: 15] [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
Antenatal corticosteroid therapy (ACT) has many beneficial effects on preterm infants. The cellular mechanisms of action of ACT include beta-adrenergic receptor-mediated cAMP generation. This study investigated the effects of ACT on sympathoadrenal mechanisms during immediate postnatal adaptation of preterm infants. Plasma epinephrine, norepinephrine, 3,4-dihydroxyphenylglycol, and cAMP were measured within 12 h after birth in 103 preterm infants (gestational age 24-36 wk), who were divided into two groups (non-ACT and ACT group) according to whether the mother had received dexamethasone treatment. Infants in the ACT group had significantly lower concentrations of plasma catecholamines than infants in the non-ACT group; plasma epinephrine was 38% lower, and plasma norepinephrine was 20-40% lower in the ACT group, depending on gestational age (r = -0.37 in the non-ACT group and r = -0.28 in the ACT group, p < 0.05). Plasma cAMP concentrations were similar in the two groups. Antihypertensive treatment of the mother was associated with low plasma cAMP (p < 0.001), whereas tocolytic treatment was associated with high plasma cAMP (p = 0.001) of the infant. The results indicate that ACT attenuates the birth-related increase in plasma catecholamines. Still, plasma cAMP levels remain high, which suggests enhanced beta-adrenoceptor signaling after ACT.
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Affiliation(s)
- J Kallio
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Finland
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Soulier V, Peyronnet J, Pequignot JM, Cottet-Emard JM, Lagercrantz H, Dalmaz Y. Long-term impairment in the neurochemical activity of the sympathoadrenal system after neonatal hypoxia in the rat. Pediatr Res 1997; 42:30-8. [PMID: 9212034 DOI: 10.1203/00006450-199707000-00006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The study evaluates the long-term effect of neonatal hypoxia on the neurochemical activity of the sympathoadrenal system in the rat. One-day-old male pups were exposed to hypoxia (10% O2) for 6 d and thereafter reared under normoxia. Neonatal hypoxia reduced the body weight of 3- and 8-wk-old rats and did not change the blood pressure at 6 wk of age. In sympathetic ganglia, the content and/or turnover rates of norepinephrine were reduced in neonatal-hypoxic rats of 3 and 8 wk of age, but the content and turnover rates of dopamine were unaltered. The effect was not dependent on the type of ganglion. In the superior cervical ganglion, neonatal hypoxia had a selective effect on the type of catecholamine (dopamine versus norepinephrine), thus suggesting a selective-altered maturation of noradrenergic neurons, but presumably not of the dopaminergic small, intensely fluorescent cells. A long-term deficiency in adrenal activity was the consequence of neonatal hypoxia, as shown by the decrease in the content and turnover rate of dopamine. Neonatal hypoxia elicited a long-term decrease in the content and turnover rates of norepinephrine in heart and lungs but failed to induce a significant effect in kidneys. However, this effect was not tissue-specific. Data provide evidence that a hypoxic episode occurring during a critical period of development in the rat induces a long lasting decrease in the neurochemical activity of the sympathoadrenal system. These results are discussed in terms of their implications for human pathology.
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Affiliation(s)
- V Soulier
- UMR 5578, Physiologie des régulations énergétiques, cellulaires et moléculaires, Faculté de Médecine Grange Blanche, Lyon, France
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Bzoskie L, Yen J, Tseng YT, Blount L, Kashiwai K, Padbury JF. Human placental norepinephrine transporter mRNA: expression and correlation with fetal condition at birth. Placenta 1997; 18:205-10. [PMID: 9089783 DOI: 10.1016/s0143-4004(97)90094-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The purpose of this study was to determine the primary form of human placental norepinephrine transporter (hNET) mRNA expressed in the human placenta and to compare the level of expression in normal pregnancies and in pregnancies complicated by drug exposure or other forms of physiological derangement. We used the hNET cDNA to measure RNA extracted from placenta and examined placental RNA following complicated and uncomplicated pregnancies. To compare transporter expression and its relation to fetal condition at birth, umbilical arterial plasma catecholamine levels, umbilical arterial blood gases and placental transporter mRNA level were compared by linear regression analysis. Uncomplicated pregnancies had a higher level of placental norepinephrine transporter mRNA than complicated pregnancies. An inverse relationship between umbilical cord norepinephrine level and transporter expression was demonstrated. We conclude that placental transporter expression represents an important and newly described metabolic function of the placenta. Placental catecholamine clearance mediated via the placental NET may be important in the pathophysiology of disorders associated with placental dysfunction, impaired placental blood flow or intrauterine growth retardation. This may also explain the adverse effects of drugs, such as cocaine, which block catecholamine transport.
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Affiliation(s)
- L Bzoskie
- Department of Pediatrics, Harbor-UCLA Medical Center, USA
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Stein HM, Martinez A, Oyama K, Blount L, Padbury JF. Effect of corticosteroids on free and sulfoconjugated catecholamines at birth in premature newborn sheep. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:E28-32. [PMID: 7840178 DOI: 10.1152/ajpendo.1995.268.1.e28] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We previously demonstrated that prenatal corticosteroids attenuated the expected exponential increase in circulating catecholamines at birth. The present studies were undertaken to determine if alteration in sulfoconjugation could account for this attenuation. Catheterized fetal lambs received saline (n = 6) or corticosteroids (n = 8) intravenously for 60 h. The lambs were delivered by cesarean section at 130 +/- 1 days gestation. Ventilatory and cardiovascular responses and plasma catecholamine concentrations were measured for 2 h after birth. Although plasma free catecholamines levels were higher in controls than in corticosteroid-treated fetuses, the sulfoconjugated levels were similar in the two groups. Thus the corticosteroid-treated fetuses had a higher proportion of plasma sulfoconjugated catecholamines consistent with the possibility that sulfoconjugation was augmented during intrauterine life. After birth, the corticosteroid-treated animals showed an attenuated increase in plasma free catecholamine levels compared with controls but a similar increase in sulfoconjugated catecholamine levels to the control animals. The proportion of plasma sulfoconjugated catecholamines was higher in the corticosteroid-treated animals; however, the increase in sulfoconjugated catecholamines was insufficient to account for the attenuated overall increase in total catecholamines in the corticosteroid-treated animals.
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Affiliation(s)
- H M Stein
- Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia 20007
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Affiliation(s)
- A Mehta
- Department of Child Health, Ninewells Hospital and Medical School, Dundee
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