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Darby JRT, Saini BS, Holman SL, Hammond SJ, Perumal SR, Macgowan CK, Seed M, Morrison JL. Acute-on-chronic: using magnetic resonance imaging to disentangle the haemodynamic responses to acute and chronic fetal hypoxaemia. Front Med (Lausanne) 2024; 11:1340012. [PMID: 38933113 PMCID: PMC11199546 DOI: 10.3389/fmed.2024.1340012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Introduction The fetal haemodynamic response to acute episodes of hypoxaemia are well characterised. However, how these responses change when the hypoxaemia becomes more chronic in nature such as that associated with fetal growth restriction (FGR), is less well understood. Herein, we utilised a combination of clinically relevant MRI techniques to comprehensively characterize and differentiate the haemodynamic responses occurring during acute and chronic periods of fetal hypoxaemia. Methods Prior to conception, carunclectomy surgery was performed on non-pregnant ewes to induce FGR. At 108-110 days (d) gestational age (GA), pregnant ewes bearing control (n = 12) and FGR (n = 9) fetuses underwent fetal catheterisation surgery. At 117-119 days GA, ewes underwent MRI sessions where phase-contrast (PC) and T2 oximetry were used to measure blood flow and oxygenation, respectively, throughout the fetal circulation during a normoxia and then an acute hypoxia state. Results Fetal oxygen delivery (DO2) was lower in FGR fetuses than controls during the normoxia state but cerebral DO2 remained similar between fetal groups. Acute hypoxia reduced both overall fetal and cerebral DO2. FGR increased ductus venosus (DV) and foramen ovale (FO) blood flow during both the normoxia and acute hypoxia states. Pulmonary blood flow (PBF) was lower in FGR fetuses during the normoxia state but similar to controls during the acute hypoxia state when PBF in controls was decreased. Conclusion Despite a prevailing level of chronic hypoxaemia, the FGR fetus upregulates the preferential streaming of oxygen-rich blood via the DV-FO pathway to maintain cerebral DO2. However, this upregulation is unable to maintain cerebral DO2 during further exposure to an acute episode of hypoxaemia. The haemodynamic alterations required at the level of the liver and lung to allow the DV-FO pathway to maintain cerebral DO2, may have lasting consequences on hepatic function and pulmonary vascular regulation after birth.
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Affiliation(s)
- Jack R. T. Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Brahmdeep S. Saini
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
| | - Stacey L. Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Sarah J. Hammond
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Sunthara Rajan Perumal
- Preclinical, Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, SA, Australia
| | - Christopher K. Macgowan
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
| | - Mike Seed
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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Darby JRT, Flouri D, Cho SKS, Williams GK, Holman SL, Meakin AS, Wiese MD, David AL, Macgowan CK, Seed M, Melbourne A, Morrison JL. Maternal tadalafil treatment does not increase uterine artery blood flow or oxygen delivery in the pregnant ewe. Exp Physiol 2024; 109:980-991. [PMID: 38606906 PMCID: PMC11140180 DOI: 10.1113/ep091593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/26/2024] [Indexed: 04/13/2024]
Abstract
Increasing placental perfusion (PP) could improve outcomes of growth-restricted fetuses. One way of increasing PP may be by using phosphodiesterase (PDE)-5 inhibitors, which induce vasodilatation of vascular beds. We used a combination of clinically relevant magnetic resonance imaging (MRI) techniques to characterize the impact that tadalafil infusion has on maternal, placental and fetal circulations. At 116-117 days' gestational age (dGA; term, 150 days), pregnant ewes (n = 6) underwent fetal catheterization surgery. At 120-123 dGA ewes were anaesthetized and MRI scans were performed during three acquisition windows: a basal state and then ∼15-75 min (TAD 1) and ∼75-135 min (TAD 2) post maternal administration (24 mg; intravenous bolus) of tadalafil. Phase contrast MRI and T2 oximetry were used to measure blood flow and oxygen delivery. Placental diffusion and PP were assessed using the Diffusion-Relaxation Combined Imaging for Detailed Placental Evaluation-'DECIDE' technique. Uterine artery (UtA) blood flow when normalized to maternal left ventricular cardiac output (LVCO) was reduced in both TAD periods. DECIDE imaging found no impact of tadalafil on placental diffusivity or fetoplacental blood volume fraction. Maternal-placental blood volume fraction was increased in the TAD 2 period. FetalD O 2 ${D_{{{\mathrm{O}}_2}}}$ andV ̇ O 2 ${\dot V_{{{\mathrm{O}}_2}}}$ were not affected by maternal tadalafil administration. Maternal tadalafil administration did not increase UtA blood flow and thus may not be an effective vasodilator at the level of the UtAs. The increased maternal-placental blood volume fraction may indicate local vasodilatation of the maternal intervillous space, which may have compensated for the reduced proportion of UtAD O 2 ${D_{{{\mathrm{O}}_2}}}$ .
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Affiliation(s)
- Jack R. T. Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Dimitra Flouri
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Steven K. S. Cho
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Georgia K. Williams
- Preclinical, Imaging & Research LaboratoriesSouth Australian Health & Medical Research InstituteAdelaideAustralia
| | - Stacey L. Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Ashley S. Meakin
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Michael D. Wiese
- Centre for Pharmaceutical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Anna L. David
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonUK
- National Institute for Health and Care Research (NIHR)University College London, Hospitals Biomedical Research CentreLondonUK
| | | | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
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3
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Dimasi CG, Darby JRT, Cho SKS, Saini BS, Holman SL, Meakin AS, Wiese MD, Macgowan CK, Seed M, Morrison JL. Reduced in utero substrate supply decreases mitochondrial abundance and alters the expression of metabolic signalling molecules in the fetal sheep heart. J Physiol 2023. [PMID: 37996982 DOI: 10.1113/jp285572] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/03/2023] [Indexed: 11/25/2023] Open
Abstract
Babies born with fetal growth restriction (FGR) are at higher risk of developing cardiometabolic diseases across the life course. The reduction in substrate supply to the developing fetus that causes FGR not only alters cardiac growth and structure but may have deleterious effects on metabolism and function. Using a sheep model of placental restriction to induce FGR, we investigated key cardiac metabolic and functional markers that may be altered in FGR. We also employed phase-contrast magnetic resonance imaging MRI to assess left ventricular cardiac output (LVCO) as a measure of cardiac function. We hypothesized that signalling molecules involved in cardiac fatty acid utilisation and contractility would be impaired by FGR and that this would have a negative impact on LVCO in the late gestation fetus. Key glucose (GLUT4 protein) and fatty acid (FATP, CD36 gene expression) substrate transporters were significantly reduced in the hearts of FGR fetuses. We also found reduced mitochondrial numbers as well as abundance of electron transport chain complexes (complexes II and IV). These data suggest that FGR diminishes metabolic and mitochondrial capacity in the fetal heart; however, alterations were not correlated with fetal LVCO. Overall, these data show that FGR alters fetal cardiac metabolism in late gestation. If sustained ex utero, this altered metabolic profile may contribute to poor cardiac outcomes in FGR-born individuals after birth. KEY POINTS: Around the time of birth, substrate utilisation in the fetal heart switches from carbohydrates to fatty acids. However, the effect of fetal growth restriction (FGR) on this switch, and thus the ability of the fetal heart to effectively metabolise fatty acids, is not fully understood. Using a sheep model of early onset FGR, we observed significant downregulation in mRNA expression of fatty acid receptors CD36 and FABP in the fetal heart. FGR fetuses also had significantly lower cardiac mitochondrial abundance than controls. There was a reduction in abundance of complexes II and IV within the electron transport chain of the FGR fetal heart, suggesting altered ATP production. This indicates reduced fatty acid metabolism and mitochondrial function in the heart of the FGR fetus, which may have detrimental long-term implications and contribute to increased risk of cardiovascular disease later in life.
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Affiliation(s)
- Catherine G Dimasi
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Steven K S Cho
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Brahmdeep S Saini
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
- Research Institute, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Ashley S Meakin
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Michael D Wiese
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Christopher K Macgowan
- Research Institute, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Biophysics, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mike Seed
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Research Institute, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Research Institute, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
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Domingues RR, Wiltbank MC, Hernandez LL. Maternal serotonin: implications for the use of selective serotonin reuptake inhibitors during gestation†. Biol Reprod 2023; 109:17-28. [PMID: 37098165 PMCID: PMC10344603 DOI: 10.1093/biolre/ioad046] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/10/2023] [Accepted: 04/17/2023] [Indexed: 04/27/2023] Open
Abstract
Maternal use of antidepressants has increased throughout the last decades; selective serotonin reuptake inhibitors (SSRI) are the most prescribed antidepressants. Despite the widespread use of SSRI by women during reproductive age and pregnant women, an increasing amount of research warns of possible detrimental effects of maternal use of SSRI during pregnancy including low birthweight/small for gestational age and preterm birth. In this review, we revisited the impact of maternal use of SSRI during pregnancy, its impact on serotonin homeostasis in the maternal and fetal circulation and the placenta, and its impact on pregnancy outcomes-particularly intrauterine growth restriction and preterm birth. Maternal use of SSRI increases maternal and fetal serotonin. The increase in maternal circulating serotonin and serotonin signaling likely promotes vasoconstriction of the uterine and placental vascular beds decreasing blood perfusion to the uterus and consequently to the placenta and fetus with potential impact on placental function and fetal development. Several adverse pregnancy outcomes are similar between women, sheep, and rodents (decreased placental size, decreased birthweight, shorter gestation length/preterm birth, neonatal morbidity, and mortality) highlighting the importance of animal studies to assess the impacts of SSRI. Herein, we address the complex interactions between maternal SSRI use during gestation, circulating serotonin, and the regulation of blood perfusion to the uterus and fetoplacental unit, fetal growth, and pregnancy complications.
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Affiliation(s)
- Rafael R Domingues
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Milo C Wiltbank
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Laura L Hernandez
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
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5
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Darby JRT, Williams GK, Cho SKS, Meakin AS, Holman SL, Quinn M, Wiese MD, Macgowan CK, Seed M, Morrison JL. Acute resveratrol exposure does not impact hemodynamics of the fetal sheep. Physiol Rep 2023; 11:e15749. [PMID: 37332034 PMCID: PMC10277215 DOI: 10.14814/phy2.15749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/29/2023] [Accepted: 05/29/2023] [Indexed: 06/20/2023] Open
Abstract
Babies born growth restricted are at an increased risk of both poor short-and long-term outcomes. Current interventions to improve fetal growth are ineffective and do not lower the lifetime risk of poor health status. Maternal resveratrol (RSV) treatment increases uterine artery blood flow, fetal oxygenation, and fetal weight. However, studies suggest that diets high in polyphenols such as RSV may impair fetal hemodynamics. We aimed to characterize the effect of RSV on fetal hemodynamics to further assess its safety as an intervention strategy. Pregnant ewes underwent magnetic resonance imaging (MRI) scans to measure blood flow and oxygenation within the fetal circulation using phase contrast-MRI and T2 oximetry. Blood flow and oxygenation measures were performed in a basal state and then repeated while the fetus was exposed to RSV. Fetal blood pressure and heart rate were not different between states. RSV did not impact fetal oxygen delivery (DO2 ) or consumption (VO2 ). Blood flow and oxygen delivery throughout the major vessels of the fetal circulation were not different between basal and RSV states. As such, acute exposure of the fetus to RSV does not directly impact fetal hemodynamics. This strengthens the rationale for the use of RSV as an intervention strategy against fetal growth restriction.
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Affiliation(s)
- Jack R. T. Darby
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Georgia K. Williams
- Preclinical, Imaging and Research LaboratoriesSouth Australian Health and Medical Research InstituteAdelaideSouth AustraliaAustralia
| | - Steven K. S. Cho
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Ashley S. Meakin
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Stacey L. Holman
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Megan Quinn
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Michael D. Wiese
- Centre for Pharmaceutical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | | | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Janna L. Morrison
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
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6
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Dimasi CG, Lazniewska J, Plush SE, Saini BS, Holman SL, Cho SKS, Wiese MD, Sorvina A, Macgowan CK, Seed M, Brooks DA, Morrison JL, Darby JRT. Redox ratio in the left ventricle of the growth restricted fetus is positively correlated with cardiac output. JOURNAL OF BIOPHOTONICS 2021; 14:e202100157. [PMID: 34499415 DOI: 10.1002/jbio.202100157] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Intrauterine growth restriction (IUGR) is a result of limited substrate supply to the developing fetus in utero, and can be caused by either placental, genetic or environmental factors. Babies born IUGR can have poor long-term health outcomes, including being at higher risk of developing cardiovascular disease. Limited substrate supply in the IUGR fetus not only changes the structure of the heart but may also affect metabolism and function of the developing heart. We have utilised two imaging modalities, two-photon microscopy and phase-contrast MRI (PC-MRI), to assess alterations in cardiac metabolism and function using a sheep model of IUGR. Two-photon imaging revealed that the left ventricle of IUGR fetuses (at 140-141 d GA) had a reduced optical redox ratio, suggesting a reliance on glycolysis for ATP production. Concurrently, the use of PC-MRI to measure foetal left ventricular cardiac output (LVCO) revealed a positive correlation between LVCO and redox ratio in IUGR, but not control fetuses. These data suggest that altered heart metabolism in IUGR fetuses is indicative of reduced cardiac output, which may contribute to poor cardiac outcomes in adulthood.
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Affiliation(s)
- Catherine G Dimasi
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Joanna Lazniewska
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Sally E Plush
- Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Steven K S Cho
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael D Wiese
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alexandra Sorvina
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Christopher K Macgowan
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mike Seed
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Doug A Brooks
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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7
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Ren J, Darby JRT, Lock MC, Holman SL, Saini BS, Bradshaw EL, Orgeig S, Perumal SR, Wiese MD, Macgowan CK, Seed M, Morrison JL. Impact of maternal late gestation undernutrition on surfactant maturation, pulmonary blood flow and oxygen delivery measured by magnetic resonance imaging in the sheep fetus. J Physiol 2021; 599:4705-4724. [PMID: 34487347 DOI: 10.1113/jp281292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 09/01/2021] [Indexed: 11/08/2022] Open
Abstract
Restriction of fetal substrate supply has an adverse effect on surfactant maturation in the lung and thus affects the transition from in utero placental oxygenation to pulmonary ventilation ex utero. The effects on surfactant maturation are mediated by alteration in mechanisms regulating surfactant protein and phospholipid synthesis. This study aimed to determine the effects of late gestation maternal undernutrition (LGUN) and LGUN plus fetal glucose infusion (LGUN+G) compared to Control on surfactant maturation and lung development, and the relationship with pulmonary blood flow and oxygen delivery ( D O 2 ) measured by magnetic resonance imaging (MRI) with molecules that regulate lung development. LGUN from 115 to 140 days' gestation significantly decreased fetal body weight, which was normalized by glucose infusion. LGUN and LGUN+G resulted in decreased fetal plasma glucose concentration, with no change in fetal arterial P O 2 compared to control. There was no effect of LGUN and LGUN+G on the mRNA expression of surfactant proteins (SFTP) and genes regulating surfactant maturation in the fetal lung. However, blood flow in the main pulmonary artery was significantly increased in LGUN, despite no change in blood flow in the left or right pulmonary artery and D O 2 to the fetal lung. There was a negative relationship between left pulmonary artery flow and D O 2 to the left lung with SFTP-B and GLUT1 mRNA expression, while their relationship with VEGFR2 was positive. These results suggest that increased pulmonary blood flow measured by MRI may have an adverse effect on surfactant maturation during fetal lung development. KEY POINTS: Maternal undernutrition during gestation alters fetal lung development by impacting surfactant maturation. However, the direction of change remains controversial. We examined the effects of maternal late gestation maternal undernutrition (LGUN) on maternal and fetal outcomes, signalling pathways involved in fetal lung development, pulmonary haemodynamics and oxygen delivery in sheep using a combination of molecular and magnetic resonance imaging (MRI) techniques. LGUN decreased fetal plasma glucose concentration without affecting arterial P O 2 . Surfactant maturation was not affected; however, main pulmonary artery blood flow was significantly increased in the LGUN fetuses. This is the first study to explore the relationship between in utero MRI measures of pulmonary haemodynamics and lung development. Across all treatment groups, left pulmonary artery blood flow and oxygen delivery were negatively correlated with surfactant protein B mRNA and protein expression in late gestation.
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Affiliation(s)
- Jiaqi Ren
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Emma L Bradshaw
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sandra Orgeig
- UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sunthara R Perumal
- Preclinical Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Michael D Wiese
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | | | - Mike Seed
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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8
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Lazniewska J, Darby JRT, Holman SL, Sorvina A, Plush SE, Massi M, Brooks DA, Morrison JL. In utero substrate restriction by placental insufficiency or maternal undernutrition decreases optical redox ratio in foetal perirenal fat. JOURNAL OF BIOPHOTONICS 2021; 14:e202000322. [PMID: 33389813 DOI: 10.1002/jbio.202000322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/04/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Intrauterine growth restriction (IUGR) can result from reduced delivery of substrates, including oxygen and glucose, during pregnancy and may be caused by either placental insufficiency or maternal undernutrition. As a consequence of IUGR, there is altered programming of adipose tissue and this can be associated with metabolic diseases later in life. We have utilised two sheep models of IUGR, placental restriction and late gestation undernutrition, to determine the metabolic effects of growth restriction on foetal perirenal adipose tissue (PAT). Two-photon microscopy was employed to obtain an optical redox ratio, which gives an indication of cell metabolism. PAT of IUGR foetuses exhibited higher metabolic activity, altered lipid droplet morphology, upregulation of cytochrome c oxidase subunit genes and decreased expression of genes involved in growth and differentiation. Our results indicate that there are adaptations in PAT of IUGR foetuses that might be protective and ensure survival in response to an IUGR insult.
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Affiliation(s)
- Joanna Lazniewska
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alexandra Sorvina
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sally E Plush
- Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Massimiliano Massi
- Department of Chemistry, Curtin University, Perth, Western Australia, Australia
| | - Doug A Brooks
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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9
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Saini BS, Darby JRT, Marini D, Portnoy S, Lock MC, Yin Soo J, Holman SL, Perumal SR, Wald RM, Windrim R, Macgowan CK, Kingdom JC, Morrison JL, Seed M. An MRI approach to assess placental function in healthy humans and sheep. J Physiol 2021; 599:2573-2602. [PMID: 33675040 DOI: 10.1113/jp281002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/15/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Human placental function is evaluated using non-invasive Doppler ultrasound of umbilical and uterine artery pulsatility indices as measures of resistance in placental vascular beds, while measurement of placental oxygen consumption ( V O 2 ) is only possible during Caesarean delivery. This study shows the feasibility of using magnetic resonance imaging (MRI) in utero to measure blood flow and oxygen content in uterine and umbilical vessels to calculate oxygen delivery to and V O 2 by the gravid uterus, uteroplacenta and fetus. Normal late gestational human uteroplacental V O 2 by MRI was ∼4 ml min-1 kg-1 fetal weight, which was similar to our MRI measurements in sheep and to those previously measured using invasive techniques. Our MRI approach can quantify uteroplacental V O 2 , which involves the quantification of maternal- and fetal-placental blood flows, fetal oxygen delivery and V O 2 , and the oxygen gradient between uterine- and umbilical-venous blood, providing a comprehensive assessment of placental function with clinical potential. ABSTRACT It has not been feasible to perform routine clinical measurement of human placental oxygen consumption ( V O 2 ) and in vitro studies do not reflect true metabolism in utero. Here we propose an MRI method to non-invasively quantify in utero placental and fetal oxygen delivery ( D O 2 ) and V O 2 in healthy humans and sheep. Women (n = 20) and Merino sheep (n = 10; 23 sets of measurements) with singleton pregnancies underwent an MRI in late gestation (36 ± 2 weeks and 128 ± 9 days, respectively; mean ± SD). Blood flow (phase-contrast) and oxygen content (T1 and T2 relaxometry) were measured in the major uterine- and umbilical-placental vessels, allowing calculation of uteroplacental and fetal D O 2 and V O 2 . Maternal D O 2 (ml min-1 kg-1 fetus) to the gravid uterus was similar in humans and sheep (human = 54 ± 15, sheep = 53 ± 21, P = 0.854), while fetal D O 2 (human = 25 ± 4, sheep = 22 ± 5, P = 0.049) was slightly lower in sheep. Uteroplacental and fetal V O 2 (ml min-1 kg-1 fetus; uteroplacental: human = 4.1 ± 1.5, sheep = 3.5 ± 1.9, P = 0.281; fetus: human = 6.8 ± 1.3, sheep = 7.2 ± 1.7, P = 0.426) were similar between species. Late gestational uteroplacental:fetal V O 2 ratio did not change with age (human, P = 0.256; sheep, P = 0.121). Human umbilical blood flow (ml min-1 kg-1 fetus) decreased with advancing age (P = 0.008), while fetal V O 2 was preserved through an increase in oxygen extraction (P = 0.046). By contrast, sheep fetal V O 2 was preserved through stable umbilical flow (ml min-1 kg-1 ; P = 0.443) and oxygen extraction (P = 0.582). MRI derived measurements of uteroplacental and fetal V O 2 between humans and sheep were similar and in keeping with prior data obtained using invasive techniques. Taken together, these data confirm the reliability of our approach, which offers a novel clinical 'placental function test'.
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Affiliation(s)
- Brahmdeep S Saini
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Division of Cardiology, Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Davide Marini
- Division of Cardiology, Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada
| | - Sharon Portnoy
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sunthara R Perumal
- Preclinical, Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, South Australia, 5086, Australia
| | - Rachel M Wald
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, ON, M5G 2N2, Canada
| | - Rory Windrim
- Maternal-Fetal Medicine Division, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1E2, Canada
| | - Christopher K Macgowan
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Medical Biophysics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - John C Kingdom
- Maternal-Fetal Medicine Division, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1E2, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Mike Seed
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Division of Cardiology, Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.,Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Obstetrics and Gynaecology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1E2, Canada
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10
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Aujla T, Darby JRT, Saini BS, Lock MC, Holman SL, Bradshaw EL, Perumal SR, McInnes SJP, Voelcker NH, Wiese MD, Macgowan CK, Seed M, Morrison JL. Impact of resveratrol-mediated increase in uterine artery blood flow on fetal haemodynamics, blood pressure and oxygenation in sheep. Exp Physiol 2021; 106:1166-1180. [PMID: 33600040 DOI: 10.1113/ep089237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/15/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Uterine artery blood flow helps to maintain fetal oxygen and nutrient delivery. We investigated the effects of increased uterine artery blood flow mediated by resveratrol on fetal growth, haemodynamics, blood pressure regulation and oxygenation in pregnant sheep. What is the main finding and its importance? Fetuses from resveratrol-treated ewes were significantly larger and exhibited a haemodynamic profile that might promote peripheral growth. Absolute uterine artery blood flow was positively correlated with umbilical vein oxygen saturation, absolute fetal oxygen delivery and fetal growth. Increasing uterine artery blood flow with compounds such as resveratrol might have clinical significance for pregnancy conditions in which fetal growth and oxygenation are compromised. ABSTRACT High placental vascular resistance hinders uterine artery (UtA) blood flow and fetal substrate delivery. In the same group of animals as the present study, we have previously shown that resveratrol (RSV) increases UtA blood flow, fetal weight and oxygenation in an ovine model of human pregnancy. However, the mechanisms behind changes in growth and the effects of increases in UtA blood flow on fetal circulatory physiology have yet to be investigated. Twin-bearing ewes received s.c. vehicle (VEH, n = 5) or RSV (n = 6) delivery systems at 113 days of gestation (term = 150 days). Magnetic resonance imaging was performed at 123-124 days to quantify fetal volume, blood flow and oxygen saturation of major fetal vessels. At 128 days, i.v. infusions of sodium nitroprusside and phenylephrine were administered to study the vascular tone of the fetal descending aorta. Maternal RSV increased fetal body volume (P = 0.0075) and weight (P = 0.0358), with no change in brain volume or brain weight. There was a positive relationship between absolute UtA blood flow and umbilical vein oxygen saturation, absolute fetal oxygen delivery and combined fetal twin volume (all P ≤ 0.05). There were no differences between groups in fetal haemodynamics or blood pressure regulation except for higher blood flow to the lower body in RSV fetuses (P = 0.0170). The observed increase in fetal weight might be helpful in pregnancy conditions in which fetal growth and oxygen delivery are compromised. Further preclinical investigations on the mechanism(s) accounting for these changes and the potential to improve growth in complicated pregnancies are warranted.
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Affiliation(s)
- Tanroop Aujla
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Emma L Bradshaw
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, South Australia, Australia
| | - Steven J P McInnes
- UniSA STEM, University of South Australia, Adelaide, South Australia, Australia
| | - Nicolas H Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Clayton, Victoria, Australia.,Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia
| | - Michael D Wiese
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Christopher K Macgowan
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mike Seed
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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11
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Abstract
Medical care is predicated on 'do no harm', yet the urgency to find drugs and vaccines to treat or prevent COVID-19 has led to an extraordinary effort to develop and test new therapies. Whilst this is an essential cornerstone of a united global response to the COVID-19 pandemic, the absolute requirements for meticulous efficacy and safety data remain. This is especially pertinent to the needs of pregnant women; a group traditionally poorly represented in drug trials, yet a group at heightened risk of unintended adverse materno-fetal consequences due to the unique physiology of pregnancy and the life course implications of fetal or neonatal drug exposure. However, due to the complexities of drug trial participation when pregnant (be they vaccines or therapeutics for acute disease), many clinical drug trials will exclude them. Clinicians must determine the best course of drug treatment with a dearth of evidence from either clinical or preclinical studies, where at least in the short term they may be more focused on the outcome of the mother than of her offspring.
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12
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Campbell KSJ, Collier AC, Irvine MA, Brain U, Rurak DW, Oberlander TF, Lim KI. Maternal Serotonin Reuptake Inhibitor Antidepressants Have Acute Effects on Fetal Heart Rate Variability in Late Gestation. Front Psychiatry 2021; 12:680177. [PMID: 34483982 PMCID: PMC8415315 DOI: 10.3389/fpsyt.2021.680177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 07/14/2021] [Indexed: 01/30/2023] Open
Abstract
Background: Prenatal exposure to serotonin reuptake inhibitor (SRI) antidepressants increases risk for adverse neurodevelopmental outcomes, yet little is known about whether effects are present before birth. In relation to maternal SRI pharmacokinetics, this study investigated chronic and acute effects of prenatal SRI exposure on third-trimester fetal heart rate variability (HRV), while evaluating confounding effects of maternal depressed mood. Methods: At 36-weeks' gestation, cardiotocograph measures of fetal HR and HRV were obtained from 148 pregnant women [four groups: SRI-Depressed (n = 31), SRI-Non-Depressed (n = 18), Depressed (unmedicated; n = 42), and Control (n = 57)] before, and ~5-h after, typical SRI dose. Maternal plasma drug concentrations were quantified at baseline (pre-dose) and four time-points post-dose. Mixed effects modeling investigated group differences between baseline/pre-dose and post-dose fetal HR outcomes. Post hoc analyses investigated sex differences and dose-dependent SRI effects. Results: Maternal SRI plasma concentrations were lowest during the baseline/pre-dose fetal assessment (trough) and increased to a peak at the post-dose assessment; concentration-time curves varied widely between individuals. No group differences in fetal HR or HRV were observed at baseline/pre-dose; however, following maternal SRI dose, short-term HRV decreased in both SRI-exposed fetal groups. In the SRI-Depressed group, these post-dose decreases were displayed by male fetuses, but not females. Further, episodes of high HRV decreased post-dose relative to baseline, but only among SRI-Non-Depressed group fetuses. Higher maternal SRI doses also predicted a greater number of fetal HR decelerations. Fetuses exposed to unmedicated maternal depressed mood did not differ from Controls. Conclusions: Prenatal SRI exposure had acute post-dose effects on fetal HRV in late gestation, which differed depending on maternal mood response to SRI pharmacotherapy. Importantly, fetal SRI effects were sex-specific among mothers with persistent depressive symptoms, as only male fetuses displayed acute HRV decreases. At trough (pre-dose), chronic fetal SRI effects were not identified; however, concurrent changes in maternal SRI plasma levels suggest that fetal drug exposure is inconsistent. Acute SRI-related changes in fetal HRV may reflect a pharmacologic mechanism, a transient impairment in autonomic functioning, or an early adaption to altered serotonergic signaling, which may differ between males and females. Replication is needed to determine significance with postnatal development.
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Affiliation(s)
- Kayleigh S J Campbell
- BC Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada
| | - Abby C Collier
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Michael A Irvine
- BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Ursula Brain
- BC Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Dan W Rurak
- BC Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada
| | - Tim F Oberlander
- BC Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Kenneth I Lim
- BC Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada
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13
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Schrauben EM, Darby JRT, Saini BS, Holman SL, Lock MC, Perumal SR, Seed M, Morrison JL, Macgowan CK. Technique for comprehensive fetal hepatic blood flow assessment in sheep using 4D flow MRI. J Physiol 2020; 598:3555-3567. [PMID: 32533704 DOI: 10.1113/jp279631] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 06/04/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The comprehensive visualization and quantification of in vivo fetal hepatic haemodynamics, particularly the shunting of ductus venosus blood, has been elusive and is not yet fully understood. We introduce the combination of chronically instrumented fetal sheep and 4D flow MRI of the whole fetal liver, which allows retrospective blood flow measurement in all visible vessels as well as qualitative assessment. The applicability and usefulness of this technique is exhibited in normally grown fetal Merino sheep in mid- and late-gestation with detailed dynamic distribution of hepatic blood flow presented. The feasibility of this approach in clinical pathology is demonstrated in two growth-restricted fetuses at mid-gestation. Further exemplification of blood flow quantification is performed over major hepatic vessels. ABSTRACT Although the fetal vasculature has been demarcated and well understood for several decades, the corresponding haemodynamics permitting oxygen- and nutrient-rich blood delivery to the fetal organs has been comparatively difficult to study. We married two well-established methods: 4D flow MRI, a volumetric and dynamic blood-flow measurement technique, and chronically instrumented sheep to broadly assess fetal hepatic circulation. We performed this technique in mid- and late-gestation fetal Merino sheep under normoxemic conditions and major hepatic vasculature was segmented to quantify blood flow and related parameters. Dynamic blood flow was visualized, exhibiting an acceleration of umbilical vein blood through the ductus venosus as well as spiralling into the inferior vena cava where its stream remained separate from that of the hepatic veins and lower body. Ductus venosus changes from mid- to late-gestation included larger diameter (mid: 5.8 ± 0.9 vs. late: 7.1 ± 1.1 mm; P = 0.003) and cross-sectional area (mid: 27.1 ± 8.6 vs. late: 40.4 ± 11.8 mm2 ; P = 0.003), and lower velocity averaged over the cardiac cycle (mid: 15.7 ± 5.4 vs. late: 9.8 ± 7.0 cm s-1 ; P = 0.020). This resulted in higher magnitude blood flow (indexed to umbilical vein input) at mid-gestation in the ductus venosus (mid: 0.73 ± 0.21; late: 0.46 ± 0.21; P = 0.008). The visualization and quantification results support the further use of this technique to better understand regional blood flow changes during normal or abnormal fetal growth, as well as to observe acute haemodynamic responses to physiological challenges or drug interventions.
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Affiliation(s)
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Brahmdeep S Saini
- Heart Centre, Hospital for Sick Children, Faculty of Medicine, Institute of Medical Science, University of Toronto
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute
| | - Mike Seed
- Division of Cardiology, Hospital for Sick Children, Department of Paediatrics, University of Toronto
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Christopher K Macgowan
- Translational Medicine, Hospital for Sick Children, Department of Medical Biophysics, University of Toronto
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14
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Darby JRT, Schrauben EM, Saini BS, Holman SL, Perumal SR, Seed M, Macgowan CK, Morrison JL. Umbilical vein infusion of prostaglandin I 2 increases ductus venosus shunting of oxygen-rich blood but does not increase cerebral oxygen delivery in the fetal sheep. J Physiol 2020; 598:4957-4967. [PMID: 32776527 DOI: 10.1113/jp280019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/27/2020] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS The ductus venosus (DV) is a dynamic fetal shunt that allows substrate-rich blood from the umbilical vein to bypass the hepatic circulation. In vitro studies suggest a direct role of prostaglandin I2 (PGI2 ) in the regulation of DV tone; however, the extent of this regulation has not been determined in utero. 4D flow and T2 oximetry magnetic resonance imaging can be combined to determine blood flow and oxygen delivery within the fetal circulation. PGI2 increases DV shunting of substrate-rich blood but this does not increase cerebral oxygen delivery. ABSTRACT During fetal development, the maintenance of adequate oxygen and nutrient supply to vital organs is regulated through specialized fetal shunts. One of these shunts, the ductus venosus (DV), allows oxygen-rich blood to preferentially stream from the placenta toward the heart and brain. Herein, we combine magnetic resonance imaging (MRI) techniques that measure blood flow (4D flow) and oxygen saturation (T2 oximetry) in the fetal circuit to determine whether umbilical vein infusion of prostaglandin I2 (PGI2 , regulator of DV tone ex utero) directly dilates the DV and thus increases the preferential streaming of oxygen-rich blood toward the brain. At 114-115 days gestational age (dGA; term = 150 days), fetal sheep (n = 6) underwent surgery to implant vascular catheters in the fetal femoral artery, femoral vein, amniotic cavity and umbilical vein. Fetal MRI scans were performed at 119-124 dGA. 4D flow and T2 oximetry were performed to measure blood flow and oxygen saturation across the fetal circulation in both a basal state and whilst the fetus was receiving a continuous infusion of PGI2 . The proportion of oxygenated blood that passed through the DV from the umbilical vein was increased by PGI2 . Cerebral oxygen delivery was unchanged in the PGI2 state. This may be a result of decreased flow from the right to left side of the heart as blood flow through the foramen ovale was decreased by PGI2 . We have shown that although PGI2 acts on the DV to increase the proportion of oxygen-rich blood that bypasses the liver, this does not increase cerebral oxygen delivery in the fetal sheep.
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Affiliation(s)
- Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Eric M Schrauben
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Brahmdeep S Saini
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Sunthara Rajan Perumal
- Preclinical, Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
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15
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Cho SKS, Darby JRT, Saini BS, Lock MC, Holman SL, Lim JM, Perumal SR, Macgowan CK, Morrison JL, Seed M. Feasibility of ventricular volumetry by cardiovascular MRI to assess cardiac function in the fetal sheep. J Physiol 2020; 598:2557-2573. [PMID: 32378201 DOI: 10.1113/jp279054] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS The application of fetal cardiovascular magnetic resonance imaging (CMR) to assess fetal cardiovascular physiology and cardiac function through the quantification of ventricular volumes has previously been investigated, but the approach has not yet been fully validated. Ventricular output measurements calculated from heart rate and stroke volumes (SV) of the right and left ventricles measured by ventricular volumetry (VV) exhibited a high level of agreement with phase-contrast (PC) blood flow measurements in the main pulmonary artery and ascending aorta, respectively. Ejection fraction of the right ventricle, which is lower than that of the left ventricle in postnatal subjects, was similar to the left ventricular ejection fraction in the fetus; probably due to the different loading conditions present in the fetal circulation. This study provides evidence to support the reliability of VV in the sheep fetus, providing evidence for its use in animal models of human diseases affecting the fetal circulation. ABSTRACT The application of ventricular volumetry (VV) by cardiovascular magnetic resonance imaging (CMR) in the fetus remains challenging due to the small size of the fetal heart and high heart rate. The reliability of this technique in utero has not yet been established. The aim of this study was to assess the feasibility and reliability of VV in a fetal sheep model of human pregnancy. Right and left ventricular outputs by stroke volume (SV) measured using VV were compared with 2D phase-contrast (PC) CMR measurements of blood flow in the main pulmonary artery (MPA) and ascending aorta (AAo). At 124-140 days (d) gestation, singleton bearing Merino ewes underwent CMR under general anaesthesia using fetal femoral artery catheters, implanted at 109-117d, to trigger cine steady state free precession acquisitions of ventricular short-axis stacks. The short-axis cine stacks were segmented at end-systole and end-diastole, yielding right and left ventricular SV, ejection fraction, and cardiac outputs (SV × heart rate). PC cine acquisitions of MPA and AAo were analysed to measure blood flow, which served as comparators for the right and left cardiac outputs by VV. There was good correlation and agreement between VV and PC measures of ventricular outputs with no significant bias (r2 = 0.926; P < 0.0001; Bias = -4.7 ± 10.5 ml min-1 kg-1 ; 95% limits of agreement: -15.9 to 25.2 ml min-1 kg-1 ). This study validates fetal VV by CMR in a large animal model of human pregnancy and provides preliminary reference values of fetal sheep right and left ventricles in late gestation.
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Affiliation(s)
- Steven K S Cho
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, 5001, Australia.,Division of Cardiology, Hospital for Sick Children, Toronto, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Brahmdeep S Saini
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada.,Division of Cardiology, Hospital for Sick Children, Toronto, Canada
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Jessie Mei Lim
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, Hospital for Sick Children, Toronto, Canada
| | - Sunthara Rajan Perumal
- Preclinical, Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Christopher K Macgowan
- Translational Medicine, Hospital for Sick Children, Toronto, Canada.,Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Mike Seed
- Division of Cardiology, Hospital for Sick Children, Toronto, Canada.,Department of Paediatrics, Faculty of Medicine, University of Toronto, Toronto, Canada
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16
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Saini BS, Darby JRT, Portnoy S, Sun L, van Amerom J, Lock MC, Soo JY, Holman SL, Perumal SR, Kingdom JC, Sled JG, Macgowan CK, Morrison JL, Seed M. Normal human and sheep fetal vessel oxygen saturations by T2 magnetic resonance imaging. J Physiol 2020; 598:3259-3281. [PMID: 32372463 DOI: 10.1113/jp279725] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/30/2020] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Human fetal Doppler ultrasound and invasive blood gas measurements obtained by cordocentesis or at the time of delivery reveal similarities with sheep (an extensively used model for human fetal cardiovascular physiology). Oxygen saturation (SO2 ) measurements in human fetuses have been limited to the umbilical and scalp vessels, providing little information about normal regional SO2 differences in the fetus. Blood T2 MRI relaxometry presents a non-invasive measure of SO2 in the major fetal vessels. This study presents the first in vivo validation of fetal vessel T2 oximetry against the in vitro T2-SO2 relationship using catheterized sheep fetuses and compares the normal SO2 in the major vessels between the human and sheep fetal circulations. Human fetal vessel SO2 by T2 MRI confirms many similarities with the sheep fetal circulation and is able to demonstrate regional differences in SO2 ; in particular the significantly higher SO2 in the left versus right heart. ABSTRACT Blood T2 magnetic resonance imaging (MRI) relaxometry non-invasively measures oxygen saturation (SO2 ) in major vessels but has not been validated in fetuses in vivo. We compared the blood T2-SO2 relationship in vitro (tubes) and in vivo (vessels) in sheep, and measured SO2 across the normal human and sheep fetal circulations by T2. Singleton pregnant ewes underwent surgery to implant vascular catheters. In vitro and in vivo sheep blood T2 measurements were related to corresponding SO2 measured using a blood gas analyser, as well as relating T2 and SO2 of human fetal blood in vitro. MRI oximetry was performed in the major vessels of 30 human fetuses at 36 weeks (term, 40 weeks) and 10 fetal sheep (125 days; term, 150 days). The fidelity of in vivo fetal T2 oximetry was confirmed through comparison of in vitro and in vivo sheep blood T2-SO2 relationships (P = 0.1). SO2 was similar between human and sheep fetuses, as was the fetal oxygen extraction fraction (human, 33 ± 11%; sheep, 34 ± 7%; P = 0.798). The presence of streaming in the human fetal circulation was demonstrated by the SO2 gradient between the ascending aorta (68 ± 10%) and the main pulmonary artery (49 ± 9%; P < 0.001). Human and sheep fetal vessel MRI oximetry based on T2 is a validated approach that confirms the presence of streaming of umbilical venous blood towards the heart and brain. Streaming is important in ensuring oxygen delivery to these organs and its disruption may have important implications for organ development, especially in conditions such as congenital heart disease and fetal growth restriction.
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Affiliation(s)
- Brahmdeep S Saini
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sharon Portnoy
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Liqun Sun
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Joshua van Amerom
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, South Australia, 5086, Australia
| | - John C Kingdom
- Department of Obstetrics and Gynaecology, Maternal-Fetal Medicine, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
| | - John G Sled
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Christopher K Macgowan
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Mike Seed
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
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Whitaker-Fornek JR, Nelson JK, Lybbert CW, Pilarski JQ. Development and regulation of breathing rhythms in embryonic and hatchling birds. Respir Physiol Neurobiol 2019; 269:103246. [DOI: 10.1016/j.resp.2019.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/19/2019] [Accepted: 06/23/2019] [Indexed: 11/28/2022]
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Darby JRT, Saini BS, Soo JY, Lock MC, Holman SL, Bradshaw EL, McInnes SJP, Voelcker NH, Macgowan CK, Seed M, Wiese MD, Morrison JL. Subcutaneous maternal resveratrol treatment increases uterine artery blood flow in the pregnant ewe and increases fetal but not cardiac growth. J Physiol 2019; 597:5063-5077. [PMID: 31483497 DOI: 10.1113/jp278110] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 08/28/2019] [Indexed: 12/27/2022] Open
Abstract
KEY POINTS Substrate restriction during critical developmental windows of gestation programmes offspring for a predisposition towards cardiovascular disease in adult life. This study aimed to determine the effect of maternal resveratrol (RSV) treatment in an animal model in which chronic fetal catheterisation is possible and the timing of organ maturation reflects that of the human. Maternal RSV treatment increased uterine artery blood flow, fetal oxygenation and fetal weight. RSV was not detectable in the fetal circulation, indicating that it may not cross the sheep placenta. This study highlights RSV as a possible intervention to restore fetal substrate supply in pregnancies affected by placental insufficiency. ABSTRACT Suboptimal in utero environments with reduced substrate supply during critical developmental windows of gestation predispose offspring to non-communicable diseases such as cardiovascular disease (CVD). Improving fetal substrate supply in these pregnancies may ameliorate the predisposition these offspring have toward adult-onset CVD. This study aimed to determine the effect of maternal resveratrol (RSV) supplementation on uterine artery blood flow and the direct effects of RSV on the fetal heart in a chronically catheterised sheep model of human pregnancy. Maternal RSV treatment significantly increased uterine artery blood flow as measured by phase contrast magnetic resonance imaging, mean gestational fetal P a O 2 and S a O 2 as well as fetal weight. RSV was not detectable in the fetal circulation, and mRNA and protein expression of the histone/protein deacetylase SIRT1 did not differ between treatment groups. No effect of maternal RSV supplementation on AKT/mTOR or CAMKII signalling in the fetal left ventricle was observed. Maternal RSV supplementation is capable of increasing fetal oxygenation and growth in an animal model in which cardiac development parallels that of the human.
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Affiliation(s)
- Jack R T Darby
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Brahmdeep S Saini
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Emma L Bradshaw
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Steven J P McInnes
- Future Industries Institute, University of South Australia, Adelaide, SA, Australia.,School of Engineering, Division of Information Technology, Engineering and the Environment, University of South Australia, Adelaide, SA, Australia, 5095
| | - Nicolas H Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Victoria, Australia.,Department of Materials Science and Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | | | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael D Wiese
- School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
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Schrauben EM, Saini BS, Darby JRT, Soo JY, Lock MC, Stirrat E, Stortz G, Sled JG, Morrison JL, Seed M, Macgowan CK. Fetal hemodynamics and cardiac streaming assessed by 4D flow cardiovascular magnetic resonance in fetal sheep. J Cardiovasc Magn Reson 2019; 21:8. [PMID: 30661506 PMCID: PMC6340188 DOI: 10.1186/s12968-018-0512-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 12/04/2018] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND To date it has not been possible to obtain a comprehensive 3D assessment of fetal hemodynamics because of the technical challenges inherent in imaging small cardiac structures, movement of the fetus during data acquisition, and the difficulty of fusing data from multiple cardiac cycles when a cardiac gating signal is absent. Here we propose the combination of volumetric velocity-sensitive cardiovascular magnetic resonance imaging ("4D flow" CMR) and a specialized animal preparation (catheters to monitor fetal heart rate, anesthesia to immobilize mother and fetus) to examine fetal sheep cardiac hemodynamics in utero. METHODS Ten pregnant Merino sheep underwent surgery to implant arterial catheters in the target fetuses. Anesthetized ewes underwent 4D flow CMR with acquisition at 3 T for fetal whole-heart coverage with 1.2-1.5 mm spatial resolution and 45-62 ms temporal resolution. Flow was measured in the heart and major vessels, and particle traces were used to visualize circulatory patterns in fetal cardiovascular shunts. Conservation of mass was used to test internal 4D flow consistency, and comparison to standard 2D phase contrast (PC) CMR was performed for validation. RESULTS Streaming of blood from the ductus venosus through the foramen ovale was visualized. Flow waveforms in the major thoracic vessels and shunts displayed normal arterial and venous patterns. Combined ventricular output (CVO) was 546 mL/min per kg, and the distribution of flows (%CVO) were comparable to values obtained using other methods. Internal 4D flow consistency across 23 measurement locations was established with differences of 14.2 ± 12.1%. Compared with 2D PC CMR, 4D flow showed a strong correlation (R2 = 0.85) but underestimated flow (bias = - 21.88 mL/min per kg, p < 0.05). CONCLUSIONS The combination of fetal surgical preparation and 4D flow CMR enables characterization and quantification of complex flow patterns in utero. Visualized streaming of blood through normal physiological shunts confirms the complex mechanism of substrate delivery to the fetal heart and brain. Besides offering insight into normal physiology, this technology has the potential to qualitatively characterize complex flow patterns in congenital heart disease phenotypes in a large animal model, which can support the development of new interventions to improve outcomes in this population.
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Affiliation(s)
| | - Brahmdeep Singh Saini
- Heart Centre, Hospital for Sick Children, Toronto, Canada
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Jack R. T. Darby
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Mitchell C. Lock
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Elaine Stirrat
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
| | - Greg Stortz
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
| | - John G. Sled
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Mike Seed
- Division of Cardiology, Hospital for Sick Children, Toronto, Canada
- Department of Paediatrics, University of Toronto, Toronto, Canada
| | - Christopher K. Macgowan
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
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Morrison JL, Berry MJ, Botting KJ, Darby JRT, Frasch MG, Gatford KL, Giussani DA, Gray CL, Harding R, Herrera EA, Kemp MW, Lock MC, McMillen IC, Moss TJ, Musk GC, Oliver MH, Regnault TRH, Roberts CT, Soo JY, Tellam RL. Improving pregnancy outcomes in humans through studies in sheep. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1123-R1153. [PMID: 30325659 DOI: 10.1152/ajpregu.00391.2017] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Experimental studies that are relevant to human pregnancy rely on the selection of appropriate animal models as an important element in experimental design. Consideration of the strengths and weaknesses of any animal model of human disease is fundamental to effective and meaningful translation of preclinical research. Studies in sheep have made significant contributions to our understanding of the normal and abnormal development of the fetus. As a model of human pregnancy, studies in sheep have enabled scientists and clinicians to answer questions about the etiology and treatment of poor maternal, placental, and fetal health and to provide an evidence base for translation of interventions to the clinic. The aim of this review is to highlight the advances in perinatal human medicine that have been achieved following translation of research using the pregnant sheep and fetus.
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Affiliation(s)
- Janna L Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mary J Berry
- Department of Paediatrics and Child Health, University of Otago , Wellington , New Zealand
| | - Kimberley J Botting
- Department of Physiology, Development, and Neuroscience, University of Cambridge , Cambridge , United Kingdom
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Martin G Frasch
- Department of Obstetrics and Gynecology, University of Washington , Seattle, Washington
| | - Kathryn L Gatford
- Robinson Research Institute and Adelaide Medical School, University of Adelaide , Adelaide, South Australia , Australia
| | - Dino A Giussani
- Department of Physiology, Development, and Neuroscience, University of Cambridge , Cambridge , United Kingdom
| | - Clint L Gray
- Department of Paediatrics and Child Health, University of Otago , Wellington , New Zealand
| | - Richard Harding
- Department of Anatomy and Developmental Biology, Monash University , Clayton, Victoria , Australia
| | - Emilio A Herrera
- Pathophysiology Program, Biomedical Sciences Institute (ICBM), Faculty of Medicine, University of Chile , Santiago , Chile
| | - Matthew W Kemp
- Division of Obstetrics and Gynecology, University of Western Australia , Perth, Western Australia , Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Timothy J Moss
- The Ritchie Centre, Hudson Institute of Medical Research, Department of Obstetrics and Gynaecology, Monash University , Clayton, Victoria , Australia
| | - Gabrielle C Musk
- Animal Care Services, University of Western Australia , Perth, Western Australia , Australia
| | - Mark H Oliver
- Liggins Institute, University of Auckland , Auckland , New Zealand
| | - Timothy R H Regnault
- Department of Obstetrics and Gynecology and Department of Physiology and Pharmacology, Western University, and Children's Health Research Institute , London, Ontario , Canada
| | - Claire T Roberts
- Robinson Research Institute and Adelaide Medical School, University of Adelaide , Adelaide, South Australia , Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Ross L Tellam
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
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Hutchison SM, Mâsse LC, Pawluski JL, Oberlander TF. Perinatal selective serotonin reuptake inhibitor (SSRI) effects on body weight at birth and beyond: A review of animal and human studies. Reprod Toxicol 2018; 77:109-121. [DOI: 10.1016/j.reprotox.2018.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 02/04/2018] [Accepted: 02/09/2018] [Indexed: 02/07/2023]
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Soo JY, Wiese MD, Berry MJ, Morrison JL. Does poor fetal growth influence the extent of fetal exposure to maternal medications? Pharmacol Res 2018; 130:74-84. [DOI: 10.1016/j.phrs.2018.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/18/2017] [Accepted: 02/01/2018] [Indexed: 10/18/2022]
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Sorvina A, Bader CA, Lock MC, Brooks DA, Morrison JL, Plush SE. Label-free imaging of healthy and infarcted fetal sheep hearts by two-photon microscopy. JOURNAL OF BIOPHOTONICS 2018; 11:e201600296. [PMID: 28464439 DOI: 10.1002/jbio.201600296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/15/2017] [Accepted: 03/12/2017] [Indexed: 06/07/2023]
Abstract
Coronary heart disease is one of the largest causes of death worldwide, making this a significant health care issue. A critical problem for the adult human heart is that it does not undergo effective repair in response to damage, leaving patients with a poor prognosis. Unlike the adult, fetal hearts have the ability to repair after myocardial damage. Using two-photon microscopy, we have visualised the morphological and metabolic changes following myocardial infarction in sheep fetuses, to characterise response to cardiac injury in a mammalian model. Following myocardial infarction, fetal hearts showed no significant increase in collagen deposition in the region of the infarction, when compared to either the surrounding tissue or shams. In contrast, metabolic activity (i. e. NAD(P)H and FAD) was significantly reduced in the region of myocardial infarction, when compared to either the surrounding tissue or sham hearts. For comparison, we also imaged two hearts from preadolescent sheep (sham and myocardial infarction) and showed highly ordered collagen deposition with decreased metabolic activity within the infarcted area. Therefore, two-photon imaging had the capacity to image both morphological and metabolic changes in response to myocardial infarction and showed differences in the response with age. Picture: Two-photon imaging of myocardial infarction (b and d) enabled the visualisation of increased collagen (blue; Em=431 nm) and changes in other tissue autofluorescence (green; Em=489-606 nm) in fetal (a and b) and preadolescent (c and d) hearts, compared to shams (a and c). The excitation wavelength was 840 nm. Scale bars: 10 μm.
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Affiliation(s)
- Alexandra Sorvina
- Mechanisms in Cell Biology and Disease Research Group, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Christie A Bader
- Mechanisms in Cell Biology and Disease Research Group, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Douglas A Brooks
- Mechanisms in Cell Biology and Disease Research Group, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sally E Plush
- Mechanisms in Cell Biology and Disease Research Group, University of South Australia, Adelaide, South Australia, 5000, Australia
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Antenatal exposure to antidepressants is associated with altered brain development in very preterm-born neonates. Neuroscience 2017; 342:252-262. [DOI: 10.1016/j.neuroscience.2016.11.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 11/15/2016] [Accepted: 11/17/2016] [Indexed: 11/21/2022]
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A review of fundamental principles for animal models of DOHaD research: an Australian perspective. J Dev Orig Health Dis 2016; 7:449-472. [DOI: 10.1017/s2040174416000477] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Epidemiology formed the basis of ‘the Barker hypothesis’, the concept of ‘developmental programming’ and today’s discipline of the Developmental Origins of Health and Disease (DOHaD). Animal experimentation provided proof of the underlying concepts, and continues to generate knowledge of underlying mechanisms. Interventions in humans, based on DOHaD principles, will be informed by experiments in animals. As knowledge in this discipline has accumulated, from studies of humans and other animals, the complexity of interactions between genome, environment and epigenetics, has been revealed. The vast nature of programming stimuli and breadth of effects is becoming known. As a result of our accumulating knowledge we now appreciate the impact of many variables that contribute to programmed outcomes. To guide further animal research in this field, the Australia and New Zealand DOHaD society (ANZ DOHaD) Animals Models of DOHaD Research Working Group convened at the 2nd Annual ANZ DOHaD Congress in Melbourne, Australia in April 2015. This review summarizes the contributions of animal research to the understanding of DOHaD, and makes recommendations for the design and conduct of animal experiments to maximize relevance, reproducibility and translation of knowledge into improving health and well-being.
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Brummelte S, Mc Glanaghy E, Bonnin A, Oberlander TF. Developmental changes in serotonin signaling: Implications for early brain function, behavior and adaptation. Neuroscience 2016; 342:212-231. [PMID: 26905950 DOI: 10.1016/j.neuroscience.2016.02.037] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/10/2016] [Accepted: 02/16/2016] [Indexed: 02/07/2023]
Abstract
The neurotransmitter serotonin (5-HT) plays a central role in brain development, regulation of mood, stress reactivity and risk of psychiatric disorders, and thus alterations in 5-HT signaling early in life have critical implications for behavior and mental health across the life span. Drawing on preclinical and emerging human evidence this narrative review paper will examine three key aspects when considering the consequences of early life changes in 5-HT: (1) developmental origins of variations of 5-HT signaling; (2) influence of genetic and epigenetic factors; and (3) preclinical and clinical consequences of 5-HT-related changes associated with antidepressant exposure (SSRIs). The developmental consequences of altered prenatal 5-HT signaling varies greatly and outcomes depend on an ongoing interplay between biological (genetic/epigenetic variations) and environmental factors, both pre and postnatally. Emerging evidence suggests that variations in 5-HT signaling may increase sensitivity to risky home environments, but may also amplify a positive response to a nurturing environment. In this sense, factors that change central 5-HT levels may act as 'plasticity' rather than 'risk' factors associated with developmental vulnerability. Understanding the impact of early changes in 5-HT levels offers critical insights that might explain the variations in early typical brain development that underlies behavioral risk.
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Affiliation(s)
- S Brummelte
- Department of Psychology, Wayne State University, 5057 Woodward Avenue, Detroit, MI 48202, USA.
| | - E Mc Glanaghy
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada; Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - A Bonnin
- Zilkha Neurogenetic Institute and Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - T F Oberlander
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada; Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
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McGillick EV, Orgeig S, Morrison JL. Structural and molecular regulation of lung maturation by intratracheal vascular endothelial growth factor administration in the normally grown and placentally restricted fetus. J Physiol 2015; 594:1399-420. [PMID: 26537782 DOI: 10.1113/jp271113] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/31/2015] [Indexed: 12/11/2022] Open
Abstract
Inhibition of hypoxia signalling leads to respiratory distress syndrome (RDS), whereas administration of vascular endothelial growth factor (VEGF), the most widely characterized hypoxia responsive factor, protects from RDS. In the lung of the chronically hypoxaemic placentally restricted (PR) fetus, there is altered regulation of hypoxia signalling. This leads to reduced surfactant maturation in late gestation and provides evidence for the increased risk of RDS in growth restricted neonates at birth. We evaluated the effect of recombinant human VEGF administration with respect to bypassing the endogenous regulation of hypoxia signalling in the lung of the normally grown and PR sheep fetus. There was no effect of VEGF administration on fetal blood pressure or fetal breathing movements. We examined the effect on the expression of genes regulating VEGF signalling (FLT1 and KDR), angiogenesis (ANGPT1, AQP1, ADM), alveolarization (MMP2, MMP9, TIMP1, COL1A1, ELN), proliferation (IGF1, IGF2, IGF1R, MKI67, PCNA), inflammation (CCL2, CCL4, IL1B, TNFA, TGFB1, IL10) and surfactant maturation (SFTP-A, SFTP-B, SFTP-C, SFTP-D, PCYT1A, LPCAT, LAMP3, ABCA3). Despite the effects of PR on the expression of genes regulating airway remodelling, inflammatory signalling and surfactant maturation, there were very few effects of VEGF administration on gene expression in the lung of both the normally grown and PR fetus. There were, however, positive effects of VEGF administration on percentage tissue, air space and numerical density of SFTP-B positive alveolar epithelial cells in fetal lung tissue. These results provide evidence for the stimulatory effects of VEGF administration on structural maturation in the lung of both the normally grown and PR fetus.
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Affiliation(s)
- Erin V McGillick
- Early Origins of Adult Health Research Group.,Molecular & Evolutionary Physiology of the Lung Laboratory, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Sandra Orgeig
- Molecular & Evolutionary Physiology of the Lung Laboratory, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
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Kiryanova V, McAllister BB, Dyck RH. Long-term outcomes of developmental exposure to fluoxetine: a review of the animal literature. Dev Neurosci 2014; 35:437-9. [PMID: 24247012 DOI: 10.1159/000355709] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 09/17/2013] [Indexed: 11/19/2022] Open
Abstract
During and following pregnancy, women are at high risk of experiencing depression, for which fluoxetine (FLX; brand names Prozac, Sarafem, Rapiflux) is the most commonly prescribed treatment. An estimated 1.4-2.1% of pregnant women use this medication, which inhibits the reuptake of serotonin and thereby increases serotonergic activity at the synapse. Serotonin acts as a cue guiding numerous neurodevelopmental processes, and changes in the concentration of serotonin can disrupt normal in utero brain development and organization in humans and other animals, thus providing a mechanism by which maternal intake of FLX might alter neural development and ultimately behaviour. Despite this possibility, long-term alterations of behaviour and the brain have not been well studied in individuals exposed to FLX during pregnancy or soon after birth, perhaps because conducting such studies beyond infancy presents significant challenges. To remedy this problem, many researchers have turned to modelling the effects of developmental FLX exposure in non-human animals, primarily rodents. The body of literature on this topic has expanded considerably over the past several years, yet a comprehensive review is lacking. In order to fill this gap, we have summarized the findings of those studies describing the long-term behavioural and neurophysiological effects of FLX exposure in non-human animals in early development. We also discuss methodological considerations and common shortcomings of research in this area. The precise nature of the long-term effects of developmental FLX exposure remains difficult to specify, as these effects appear to be highly variable and dependent on numerous factors. Overall, however, it is clear that early FLX exposure in non-human animals can alter the development of the brain in ways that are relevant to behaviour in adulthood, decreasing exploration and social interaction, and in some cases altering anxiety- and depression-like behaviours..
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Bourke CH, Stowe ZN, Owens MJ. Prenatal antidepressant exposure: clinical and preclinical findings. Pharmacol Rev 2014; 66:435-65. [PMID: 24567054 DOI: 10.1124/pr.111.005207] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Pharmacological treatment of any maternal illness during pregnancy warrants consideration of the consequences of the illness and/or medication for both the mother and unborn child. In the case of major depressive disorder, which affects up to 10-20% of pregnant women, the deleterious effects of untreated depression on the offspring can be profound and long lasting. Progress has been made in our understanding of the mechanism(s) of action of antidepressants, fetal exposure to these medications, and serotonin's role in development. New technologies and careful study designs have enabled the accurate sampling of maternal serum, breast milk, umbilical cord serum, and infant serum psychotropic medication concentrations to characterize the magnitude of placental transfer and exposure through human breast milk. Despite this progress, the extant clinical literature is largely composed of case series, population-based patient registry data that are reliant on nonobjective means and retrospective recall to determine both medication and maternal depression exposure, and limited inclusion of suitable control groups for maternal depression. Conclusions drawn from such studies often fail to incorporate embryology/neurotransmitter ontogeny, appropriate gestational windows, or a critical discussion of statistically versus clinically significant. Similarly, preclinical studies have predominantly relied on dosing models, leading to exposures that may not be clinically relevant. The elucidation of a defined teratological effect or mechanism, if any, has yet to be conclusively demonstrated. The extant literature indicates that, in many cases, the benefits of antidepressant use during pregnancy for a depressed pregnant woman may outweigh potential risks.
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Wang KCW, Brooks DA, Thornburg KL, Morrison JL. Activation of IGF-2R stimulates cardiomyocyte hypertrophy in the late gestation sheep fetus. J Physiol 2012; 590:5425-37. [PMID: 22930271 DOI: 10.1113/jphysiol.2012.238410] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In vitro studies using rat and fetal sheep cardiomyocytes indicate that, in addition to its role as a clearance receptor, the insulin-like growth factor 2 receptor (IGF-2R) can induce cardiomyocyte hypertrophy. In the present study, we have determined the effect of specific activation of the IGF-2R in the heart of the late gestation fetus on cardiomyocyte development. Leu(27)IGF-2, an IGF-2R agonist, was infused into the fetal left circumflex coronary artery for 4 days beginning at 128.1 ± 0.4 days gestation. Ewes were humanely killed at 132.2 ± 1.2 days gestation (term, 150 days). Fetuses were delivered and hearts dissected to isolate the cardiomyocytes and to collect and snap-freeze tissue. Leu(27)IGF-2 infusion into the left circumflex coronary artery of fetal sheep increased the area of binucleated cardiomyocytes in the left, but not the right, ventricle. However, this infusion of Leu(27)IGF-2 did not change fetal weight, heart weight, blood pressure, blood gases or cardiomyocyte proliferation/binucleation. The increase in cardiomyocyte size in the Leu(27)IGF-2-infused group was associated with increased expression of proteins in the Gαs, but not the Gαq, signalling pathway. We concluded that infusion of Leu(27)IGF-2 into the left circumflex coronary artery causes cardiac IGF-2R activation in the left ventricle of the heart, and this stimulates cardiomyocyte hypertrophy in a Gαs-dependent manner.
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Affiliation(s)
- Kimberley C W Wang
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA, Australia 5001
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Oberlander TF. Fetal serotonin signaling: setting pathways for early childhood development and behavior. J Adolesc Health 2012; 51:S9-16. [PMID: 22794534 DOI: 10.1016/j.jadohealth.2012.04.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 04/20/2012] [Accepted: 04/23/2012] [Indexed: 02/07/2023]
Abstract
Finely tuning levels of the key neurotransmitter serotonin (5-hydroxytryptamine [5-HT]) during early life is essential for brain development and setting pathways for health and disorder across the early life span. Given the central role of 5-HT in brain development, regulation of mood, stress reactivity, and risk for psychiatric disorders, alterations in 5-HT signaling early in life have critical implications for behavior and mental health in childhood and adolescence. This article reviews the developmental consequences of two key influences that alter fetal 5-HT signaling: (1) in utero exposure to 5-HT reuptake inhibitor antidepressants, and (2) genetic variations in the 5-HT transporter gene (SLC6A4). The consequences of altered prenatal 5-HT signaling vary greatly, and developmental outcomes depend on an ongoing interplay between biological (genetic/epigenetic variations), experiential (prenatal drug or maternal mood exposure), and contextual (postnatal social environment) variables. Emerging evidence suggests both exposure to 5-HT reuptake inhibitors and genetic variations that affect 5-HT signaling may increase sensitivity to negative social contexts for some individuals, whereas for others, they may confer sensitivity to positive life circumstances. In this sense, factors that change central 5-HT levels may function less like influences that predict "vulnerability," but rather act like "plasticity factors." Understanding the impact of early changes in serotonergic programming offers critical insights that might explain patterns of individual differences in developmental risk and resilience.
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Affiliation(s)
- Tim F Oberlander
- Department of Pediatrics, Child and Family Research Institute, Vancouver, British Columbia, Canada.
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Lim K, Sanders A, Brain U, Riggs W, Oberlander TF, Rurak D. Third trimester fetal pulmonary artery Doppler blood flow velocity characteristics following prenatal selective serotonin reuptake inhibitor (SSRI) exposure. Early Hum Dev 2012; 88:609-15. [PMID: 22305713 DOI: 10.1016/j.earlhumdev.2012.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 01/04/2012] [Accepted: 01/15/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND There have been contradictory reports on the risks of persistent pulmonary hypertension (PPHN) in infants exposed to SSRIs in utero. However, there has been no assessment of fetal pulmonary arterial dynamics in such pregnancies. AIMS AND SUBJECTS: To measure fetal right pulmonary artery (RPA) variables using Doppler ultrasound at 36 weeks gestation in fetuses of mothers taking SSRI antidepressants (n=23) and in a control, normal pregnancy group (n=35). OUTCOME MEASURES At 36 weeks gestation, Doppler ultrasound estimates of Pulsatility Index (PI), Resistance Index (RI), vessel diameter, peak systolic velocity, mean velocity and volume flow were obtained from the fetal right pulmonary artery in a morning session (~0830), before the SSRI mothers took their daily drug dose and in an afternoon session (~1300). Venous blood was drawn at 5 time points across the day (~08:30AM, ~10:30AM, ~13:00PM, ~13:45PM, and ~15:00PM) from the SSRI treated mothers for measurement of plasma SSRI concentration using high performance liquid chromatography tandem mass spectrometry. RESULTS There were no differences in the RPA Doppler measures between the control and SSRI-exposed fetuses. However 8 of the 23 latter fetuses experience transient respiratory difficulties at birth and, in these RPA flow was significantly higher than in the SSR-exposed fetuses without respiratory problems. There were, however, no differences in RPA PI and RI between the 2 groups. CONCLUSIONS In SSRI-exposed infants with transient postnatal respiratory difficulties, fetal RPA flow in increased, likely due to partial constriction of the ductus arteriosus. However, this was not associated with PPHN.
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Affiliation(s)
- Ken Lim
- Department of Obstetrics & Gynecology, University of British Columbia, 50 West 28th Avenue, Vancouver, BC, Canada
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Hanley GE, Oberlander TF. Neurodevelopmental outcomes following prenatal exposure to serotonin reuptake inhibitor antidepressants: A “social teratogen” or moderator of developmental risk? ACTA ACUST UNITED AC 2012; 94:651-9. [DOI: 10.1002/bdra.23032] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 03/28/2012] [Accepted: 04/19/2012] [Indexed: 11/10/2022]
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Rurak D, Lim K, Sanders A, Brain U, Riggs W, Oberlander TF. Third trimester fetal heart rate and Doppler middle cerebral artery blood flow velocity characteristics during prenatal selective serotonin reuptake inhibitor exposure. Pediatr Res 2011; 70:96-101. [PMID: 21436759 DOI: 10.1203/pdr.0b013e31821ba11a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Prenatal selective serotonin reuptake inhibitor (SSRI) exposure increases the risk for adverse neonatal behavioral outcomes; although it is unknown whether altered brain function is present before birth. We investigated fetal vascular and heart rate changes at 36-wk gestation in SSRI-treated women with mood disorders (n = 29) [exposed (EXP)] and controls (n = 45) [non-EXP (NEXP)]. Fetal middle cerebral artery (MCA) flow parameters and heart rate characteristics were obtained during pre-SSRI dose morning and postdose afternoon sessions. Maternal mood and cord Hb and hematocrit were measured. Basal fetal heart rate (fHR) did not differ between groups or across the day. The fHR short- and long-term variations, accelerations, and duration of high variability episodes remained lower and did not change across the day in EXP, whereas all increased significantly in NEXP. In both groups, MCA flow velocity and volume flow increased significantly across the day. EXP MCA pulsatility index was significantly lower, as was MCA cross-sectional area. EXP cord Hb and hematocrit were significantly increased. Prenatal SSRI exposure reduced fetal MCA flow resistance and fHR variability, before and after an SSRI dose, controlling for maternal mood. These changes and the SSRI-related increased red cell indices suggest possible fetal hypoxia.
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Affiliation(s)
- Dan Rurak
- Department of Obstetrics & Gynecology, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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Kinney HC, Broadbelt KG, Haynes RL, Rognum IJ, Paterson DS. The serotonergic anatomy of the developing human medulla oblongata: implications for pediatric disorders of homeostasis. J Chem Neuroanat 2011; 41:182-99. [PMID: 21640183 DOI: 10.1016/j.jchemneu.2011.05.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 04/25/2011] [Accepted: 05/06/2011] [Indexed: 12/18/2022]
Abstract
The caudal serotonergic (5-HT) system is a critical component of a medullary "homeostatic network" that regulates protective responses to metabolic stressors such as hypoxia, hypercapnia, and hyperthermia. We define anatomically the caudal 5-HT system in the human medulla as 5-HT neuronal cell bodies located in the raphé (raphé obscurus, raphé magnus, and raphé pallidus), extra-raphé (gigantocellularis, paragigantocellularis lateralis, intermediate reticular zone, lateral reticular nucleus, and nucleus subtrigeminalis), and ventral surface (arcuate nucleus). These 5-HT neurons are adjacent to all of the respiratory- and autonomic-related nuclei in the medulla where they are positioned to modulate directly the responses of these effector nuclei. In the following review, we highlight the topography and development of the caudal 5-HT system in the human fetus and infant, and its inter-relationships with nicotinic, GABAergic, and cytokine receptors. We also summarize pediatric disorders in early life which we term "developmental serotonopathies" of the caudal (as well as rostral) 5-HT domain and which are associated with homeostatic imbalances. The delineation of the development and organization of the human caudal 5-HT system provides the critical foundation for the neuropathologic elucidation of its disorders directly in the human brain.
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Affiliation(s)
- Hannah C Kinney
- Department of Pathology, Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, United States
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Yates DT, Strosser GL, Black PL, Halalsheh RA, Lankford LM, Hernandez LL, Löest CA, Ross TT. Technical note: Effects of rumen passage on fluoxetine bioavailability in serum and effects of fluoxetine on serum prolactin concentration and demeanor in ewes1. J Anim Sci 2010; 88:3611-6. [DOI: 10.2527/jas.2010-3076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Sustained neurobehavioral effects of exposure to SSRI antidepressants during development: molecular to clinical evidence. Clin Pharmacol Ther 2009; 86:672-7. [PMID: 19890255 DOI: 10.1038/clpt.2009.201] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Selective serotonin reuptake inhibitor (SSRI) antidepressants are frequently used in the management of antenatal maternal mood disturbances. SSRIs readily cross the placenta and increase central serotonergic tone in the fetus. Given serotonin's key neurodevelopmental role, such prenatal exposure raises concerns about its impact on child development. Preclinical studies report enduring molecular, physiological, and behavioral consequences of developmental SSRI exposure. In humans, sustained developmental outcomes remain largely unstudied, and distinguishing between the effects of prenatal SSRI exposure and the impact of maternal mental illness remains a key challenge.
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Abstract
Depression has a female sex predilection with 2 to 3% of the pregnant women population presently requiring treatment with selective serotonin reuptake inhibitors (SSRI). Exposure to SSRIs in late gestation leads to clinical manifestations in as much as 30% of the neonates. These include neurobehavioral, respiratory, gastrointestinal, and somatic symptoms. Among the respiratory manifestations, persistent pulmonary hypertension syndrome is a newly recognized and concerning side effect of SSRI exposure in utero. This causal association has been reproduced in an animal model where fluoxetine administration to pregnant rats induces fetal pulmonary hypertension. The pharmacological effects of SSRI on the fetus and newborn, available treatment, and prevention strategies are discussed in this review.
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Affiliation(s)
- Jaques Belik
- The Hospital for Sick Children, University of Toronto, Toronto, Ontario, CA.
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Morrison JL, Botting KJ, Dyer JL, Williams SJ, Thornburg KL, McMillen IC. Restriction of placental function alters heart development in the sheep fetus. Am J Physiol Regul Integr Comp Physiol 2007; 293:R306-13. [PMID: 17428893 DOI: 10.1152/ajpregu.00798.2006] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Placental insufficiency, resulting in restriction of fetal substrate supply, is a major cause of intrauterine growth restriction (IUGR) and increased neonatal morbidity. Fetal adaptations to placental restriction maintain the growth of key organs, including the heart, but the impact of these adaptations on individual cardiomyocytes is unknown. Placental and hence fetal growth restriction was induced in fetal sheep by removing the majority of caruncles in the ewe before mating (placental restriction, PR). Vascular surgery was performed on 13 control and 11 PR fetuses at 110-125 days of gestation (term: 150 +/- 3 days). PR fetuses with a mean gestational Po(2) < 17 mmHg were defined as hypoxic. At postmortem (<135 or >135 days), fetal hearts were collected, and cardiomyocytes were isolated and fixed. Proliferating cardiomyocytes were counted by immunohistochemistry of Ki67 protein. Cardiomyocytes were stained with methylene blue to visualize the nuclei, and the proportion of mononucleated cells and length and width of cardiomyocytes were measured. PR resulted in chronic fetal hypoxia, IUGR, and elevated plasma cortisol concentrations. Although there was no difference in relative heart weights between control and PR fetuses, there was an increase in the proportion of mononucleated cardiomyocytes in PR fetuses. Whereas mononucleated and binucleated cardiomyocytes were smaller, the relative size of cardiomyocytes when expressed relative to heart weight was larger in PR compared with control fetuses. The increase in the relative proportion of mononucleated cardiomyocytes and the relative sparing of the growth of individual cardiomyocytes in the growth-restricted fetus are adaptations that may have long-term consequences for heart development in postnatal life.
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Affiliation(s)
- J L Morrison
- Center for the Early Origins of Adult Health, Discipline of Physiology, University of Adelaide, Adelaide, SA, Australia.
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Maternal fluoxetine infusion does not alter fetal endocrine and biophysical circadian rhythms in pregnant sheep. ACTA ACUST UNITED AC 2006; 12:356-64. [PMID: 15979548 DOI: 10.1016/j.jsgi.2005.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Depression during pregnancy is frequently treated with the selective serotonin reuptake inhibitor (SSRI), fluoxetine (FX), commonly known as Prozac (Eli Lilly & Co, Indianapolis, IN). FX potentiates serotoninergic neurotransmission and serotonin has been implicated in the regulation of circadian rhythms. We have therefore investigated the effect of chronic administration of FX on maternal and fetal circadian rhythms in sheep. METHODS Following an initial bolus dose of 70 mg FX, an 8-day continuous infusion of FX (n = 11, 98.5 microg/kg x d) was performed. Controls (n = 13) were treated with sterile water vehicle only. Maternal and fetal plasma melatonin and prolactin concentrations were determined every 3 hours for 24 hours and then every 6 hours for 24 hours beginning on the fourth day of infusion. RESULTS FX treatment did not alter either the basal or circadian rhythms of either maternal or fetal plasma melatonin and prolactin concentrations. Fetal cardiovascular and behavioral state parameters were measured continuously. While the incidence of low-voltage (LV) electrocortical (ECOG) activity was significantly reduced in fetuses in the FX group, there was no effect of FX on the diurnal rhythms in fetal arterial pressure, heart rate, breathing movements, or behavioral state. CONCLUSION These results show that maternal FX treatment does not result in significant alterations in maternal and fetal hormonal and behavioral circadian rhythms.
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Hines RN, Adams J, Buck GM, Faber W, Holson JF, Jacobson SW, Keszler M, McMartin K, Segraves RT, Singer LT, Sipes IG, Williams PL. NTP-CERHR Expert Panel Report on the reproductive and developmental toxicity of fluoxetine. ACTA ACUST UNITED AC 2005; 71:193-280. [PMID: 15334524 DOI: 10.1002/bdrb.20014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Oberlander TF, Grunau RE, Fitzgerald C, Papsdorf M, Rurak D, Riggs W. Pain reactivity in 2-month-old infants after prenatal and postnatal serotonin reuptake inhibitor medication exposure. Pediatrics 2005; 115:411-25. [PMID: 15687451 DOI: 10.1542/peds.2004-0420] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE In this prospective study, we examined biobehavioral responses to acute procedural pain at 2 months of age in infants with prenatal and postnatal selective serotonin reuptake inhibitor (SSRI) medication exposure. Based on previous findings showing reduced pain responses in newborns after prenatal exposure, we hypothesized that altered pain reactivity would also be found at 2 months of age. METHODS Facial action (Neonatal Facial Coding System) and cardiac autonomic reactivity derived from the respiratory activity and heart rate variability (HRV) responses to a painful event (heel-lance) were compared between 3 groups of infants: (1) infants with prenatal SSRI exposure alone (n = 11; fluoxetine, n = 2; paroxetine, n = 9); (2) infants with prenatal and postnatal SSRI (via breast milk) exposure (total n = 30; fluoxetine, n = 6; paroxetine, n = 20; sertraline, n = 4); and (3) control infants (n = 22; nonexposed) during baseline, lance, and recovery periods. Measures of maternal mood and drug levels were also obtained, and Bayley Scales of Infant Development-II were administered at ages 2 and 8 months. RESULTS Facial action increased in all groups immediately after the lance but was significantly lower in the pSE group during the lance period. HR among infants in the pSE and ppSE groups was significantly lower during recovery. Using measures of HRV and the transfer relationship between heart rate and respiration, exposed infants had a greater return of parasympathetic cardiac modulation in the recovery period, whereas a sustained sympathetic response continued in control infants. Although postnatal exposure via breast milk was extremely low when infant drug levels could be detected in ppSE infants, changes in HR and HRV from lance to recovery were greater compared among infants with levels too low to be quantified. Neither maternal mood nor the presence of clonazepam influenced pain responses. CONCLUSIONS Blunted facial-action responses were observed among infants with prenatal SSRI exposure alone, whereas both prenatal and postnatal exposure was associated with reduced parasympathetic withdrawal and increased parasympathetic cardiac modulation during recovery after an acute noxious event. These findings are consistent with patterns of pain reactivity observed in the newborn period in the same cohort. Given that postnatal exposure via breast milk was extremely low and altered biobehavioral pain reactivity was not associated with levels of maternal reports of depression, these data suggest possible sustained neurobehavioral outcomes beyond the newborn period. This is the first study of pain reactivity in infants with prenatal and postnatal SSRI exposure, and our findings were limited by the lack of a depressed nonmedicated control group, small sample size, and understanding of infant behaviors associated with pain reactivity that could have also have been influenced by prenatal SSRI exposure. The developmental and clinical implications of our findings remain unclear, and the mechanisms that may have altered 5-hydroxytryptamine-mediated pain modulation in infants after SSRI exposure remain to be studied. Treating maternal depression with antidepressants during and after pregnancy and promoting breastfeeding in this setting should remain a key goal for all clinicians. Additional study is needed to understand the long-term effects of prenatal and early postnatal SSRI exposure.
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Affiliation(s)
- Tim F Oberlander
- Department of Pediatrics, Biobehavioral Research Unit, Centre for Community Child Health Research, Room L408, 4480 Oak St, Vancouver, BC, Canada.
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Danielson L, McMillen IC, Dyer JL, Morrison JL. Restriction of placental growth results in greater hypotensive response to alpha-adrenergic blockade in fetal sheep during late gestation. J Physiol 2005; 563:611-20. [PMID: 15649982 PMCID: PMC1665578 DOI: 10.1113/jphysiol.2004.080523] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Placental insufficiency resulting in restriction of fetal substrate supply and fetal hypoxaemia is a major cause of restricted fetal growth and increased neonatal morbidity. Fetal adaptations to placental restriction (PR) include increases in circulating catecholamines and cortisol and decreased fetal body growth, with relative sparing of brain growth. The mechanisms underlying the redistribution of fetal cardiac output in PR fetuses are not known and the aim of this study was to determine whether maintenance of fetal blood pressure (BP) in the PR fetus is dependent on alpha-adrenergic stimulation. PR was induced by removing the majority of uterine caruncles in the ewe before conception. Sterile vascular surgery was performed on seven PR and six control fetuses at 113-120 days' gestation (term = 150 +/- 3 days). Fetuses with a mean arterial PO2 < 17 mmHg between 123 and 127 days' gestation were defined as hypoxic. There was a greater fall (P < 0.05) in fetal BP during phentolamine infusion (i.v: 5 mg bolus, 0.2 mg kg(-1) min(-1) for 2 h) in the hypoxic PR group (-15 +/- 2 mmHg) compared with normoxic controls (-5 +/- 1 mmHg). The fall in fetal BP during phentolamine infusion was directly related to the level of fetal PO2. Fetal BP and HR responses to phenylephrine (i.v.: 40 microg kg(-1)) were not different between PR and control fetuses. The maintenance of BP in the chronically hypoxic fetus is therefore dependent on alpha-adrenergic activation, and this fetal adaptation to a suboptimal intrauterine environment pre-dates the development of significant growth restriction. While this adaptation may play a critical role in the redistribution of fetal cardiac output to ensure the sparing of brain growth, it may have adverse consequences for peripheral vascular function in the neonatal period and in adult life.
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Affiliation(s)
- Li Danielson
- Centre for the Early Origins of Adult Health, Discipline of Physiology, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, SA 5005, Australia
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Morrison JL, Riggs KW, Rurak DW. Fluoxetine during pregnancy: impact on fetal development. Reprod Fertil Dev 2005; 17:641-50. [PMID: 16263070 DOI: 10.1071/rd05030] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 06/12/2005] [Indexed: 11/23/2022] Open
Abstract
Women are at greatest risk of suffering from depression during the childbearing years and thus may either become pregnant while taking an antidepressant or may require a prescription for one during pregnancy. The antidepressant fluoxetine (FX) is a selective serotonin reuptake inhibitor (SSRI), which increases serotonin neurotransmission. Serotonin is involved in the regulation of a variety of physiological systems, including the sleep–wake cycle, circadian rhythms and the hypothalamic–pituitary–adrenal axis. Each of these systems also plays an important role in fetal development. Compared with other antidepressant drugs, the SSRIs, such as FX, have fewer side effects. Because of this, they are now frequently prescribed, especially during pregnancy. Clinical studies suggest poor neonatal outcome after exposure to FX in utero. Recent studies in the sheep fetus describe the physiological effects of in utero exposure to FX with an 8 day infusion during late gestation in the sheep. This is a useful model for determining the effects of FX on fetal physiology. The fetus can be studied for weeks in its normal intrauterine environment with serial sampling of blood, thus permitting detailed studies of drug disposition in both mother and fetus combined with monitoring of fetal behavioural state and cardiovascular function. Fluoxetine causes an acute increase in plasma serotonin levels, leading to a transient reduction in uterine blood flow. This, in turn, reduces the delivery of oxygen and nutrients to the fetus, thereby presenting a mechanism for reducing growth and/or eliciting preterm delivery. Moreover, because FX crosses the placenta, the fetus is exposed directly to FX, as well as to the effects of the drug on the mother. Fluoxetine increases high-voltage/non-rapid eye movement behavioural state in the fetus after both acute and chronic exposure and, thus, may interfere with normal fetal neurodevelopment. Fluoxetine also alters hypothalamic function in the adult and increases the magnitude of the prepartum rise in fetal cortisol concentrations in sheep. Fetal FX exposure does not alter fetal circadian rhythms in melatonin or prolactin. Studies of the effects of FX exposure on fetal development in the sheep are important in defining possible physiological mechanisms that explain human clinical studies of birth outcomes after FX exposure. To date, there have been insufficient longer-term follow-up studies in any precocial species of offspring exposed to SSRIs in utero. Thus, further investigation of the long-term consequences of in utero exposure to FX and other SSRIs, as well as the mechanisms involved, are required for a complete understanding of the impact of these agents on development. This should involve studies in both humans and appropriate animal models.
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Affiliation(s)
- Janna L Morrison
- Discipline of Physiology, School of Molecular and Biomedical Science, Centre for the Early Origins of Adult Disease, University of Adelaide, Australia.
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Morrison JL, Riggs KW, Chien C, Gruber N, McMillen IC, Rurak DW. Chronic maternal fluoxetine infusion in pregnant sheep: effects on the maternal and fetal hypothalamic-pituitary-adrenal axes. Pediatr Res 2004; 56:40-6. [PMID: 15128928 DOI: 10.1203/01.pdr.0000128981.38670.28] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Depression during pregnancy is frequently treated with the selective serotonin reuptake inhibitor, fluoxetine (FX). FX increases serotonergic neurotransmission and serotonin plays a role in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. We have therefore investigated the effect of chronic administration of FX to the pregnant ewe on the maternal and fetal HPA axes. Nineteen late-gestation sheep were surgically prepared for chronic study of the fetus. FX (n = 7, 98.5 microg/kg/d) or sterile water (control, n = 8) was administered to the ewe for 8 d by constant rate i.v. infusion with an initial FX bolus dose of 70 mg. Maternal and fetal plasma ACTH and cortisol concentrations were determined at 0700 h each day. Maternal plasma ACTH concentrations fell on infusion d 2, but no changes were observed in maternal plasma cortisol concentrations. Fetal plasma ACTH concentrations increased on infusion d 7, and fetal plasma cortisol concentrations increased on infusion d 6, 7, and 8 in the FX group. In addition, the regression coefficient for the relationship between fetal ACTH and cortisol levels was significantly greater in the FX group compared with the control group. Thus, maternal FX treatment increased fetal plasma cortisol concentration. These results are of particular interest in the context that exposure of the fetus to excess glucocorticoids at critical windows during development has been shown to increase the risk of poor health outcomes in later life.
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Affiliation(s)
- Janna L Morrison
- Department of Obstetrics and Gynecology, British Columbia Research Institute for Children's & Women's Health, Vancouver, British Columbia, Canada.
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Costa LG, Steardo L, Cuomo V. Structural Effects and Neurofunctional Sequelae of Developmental Exposure to Psychotherapeutic Drugs: Experimental and Clinical Aspects. Pharmacol Rev 2004; 56:103-47. [PMID: 15001664 DOI: 10.1124/pr.56.1.5] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The advent of psychotherapeutic drugs has enabled management of mental illness and other neurological problems such as epilepsy in the general population, without requiring hospitalization. The success of these drugs in controlling symptoms has led to their widespread use in the vulnerable population of pregnant women as well, where the potential embryotoxicity of the drugs has to be weighed against the potential problems of the maternal neurological state. This review focuses on the developmental toxicity and neurotoxicity of five broad categories of widely available psychotherapeutic drugs: the neuroleptics, the antiepileptics, the antidepressants, the anxiolytics and mood stabilizers, and a newly emerging class of nonprescription drugs, the herbal remedies. A brief review of nervous system development during gestation and following parturition in mammals is provided, with a description of the development of neurochemical pathways that may be involved in the action of the psychotherapeutic agents. A thorough discussion of animal research and human clinical studies is used to determine the risk associated with the use of each drug category. The potential risks to the fetus, as demonstrated in well described neurotoxicity studies in animals, are contrasted with the often negative findings in the still limited human studies. The potential risk fo the human fetus in the continued use of these chemicals without more adequate research is also addressed. The direction of future research using psychotherapeutic drugs should more closely parallel the methodology developed in the animal laboratories, especially since these models have already been used extremely successfully in specific instances in the investigation of neurotoxic agents.
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Affiliation(s)
- Lucio G Costa
- Department of Pharmacology and Human Physiology, University of Bari Medical School, Italy
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