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Gyselaers W, Lees C. Maternal Low Volume Circulation Relates to Normotensive and Preeclamptic Fetal Growth Restriction. Front Med (Lausanne) 2022; 9:902634. [PMID: 35755049 PMCID: PMC9218216 DOI: 10.3389/fmed.2022.902634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
This narrative review summarizes current evidence on the association between maternal low volume circulation and poor fetal growth. Though much work has been devoted to the study of cardiac output and peripheral vascular resistance, a low intravascular volume may explain why high vascular resistance causes hypertension in women with preeclampsia (PE) that is associated with fetal growth restriction (FGR) and, at the same time, presents with normotension in FGR itself. Normotensive women with small for gestational age babies show normal gestational blood volume expansion superimposed upon a constitutionally low intravascular volume. Early onset preeclampsia (EPE; occurring before 32 weeks) is commonly associated with FGR, and poor plasma volume expandability may already be present before conception, thus preceding gestational volume expansion. Experimentally induced low plasma volume in rodents predisposes to poor fetal growth and interventions that enhance plasma volume expansion in FGR have shown beneficial effects on intrauterine fetal condition, prolongation of gestation and birth weight. This review makes the case for elevating the maternal intravascular volume with physical exercise with or without Nitric Oxide Donors in FGR and EPE, and evaluating its role as a potential target for prevention and/or management of these conditions.
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Affiliation(s)
- Wilfried Gyselaers
- Department of Obstetrics, Ziekenhuis Oost Limburg, Genk, Belgium.,Department of Physiology, Hasselt University, Hasselt, Belgium
| | - Christoph Lees
- Centre for Fetal Care, Queen Charlotte's and Chelsea Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom.,Department of Metabolism, Digestion and Reproduction, Institute for Reproductive and Developmental Biology, Imperial College London, London, United Kingdom.,Department of Development and Regeneration, KU Leuven, Leuven, Belgium.,Centre for Fetal Care, Queen Charlotte's and Chelsea Hospital, London, United Kingdom
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Maréchal L, Sicotte B, Caron V, Brochu M, Tremblay A. Fetal Cardiac Lipid Sensing Triggers an Early and Sex-related Metabolic Energy Switch in Intrauterine Growth Restriction. J Clin Endocrinol Metab 2021; 106:3295-3311. [PMID: 34245263 PMCID: PMC8530737 DOI: 10.1210/clinem/dgab496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Indexed: 12/21/2022]
Abstract
CONTEXT Intrauterine growth restriction (IUGR) is an immediate outcome of an adverse womb environment, exposing newborns to developing cardiometabolic disorders later in life. OBJECTIVE This study investigates the cardiac metabolic consequences and underlying mechanism of energy expenditure in developing fetuses under conditions of IUGR. METHODS Using an animal model of IUGR characterized by uteroplacental vascular insufficiency, mitochondrial function, gene profiling, lipidomic analysis, and transcriptional assay were determined in fetal cardiac tissue and cardiomyocytes. RESULTS IUGR fetuses exhibited an upregulation of key genes associated with fatty acid breakdown and β-oxidation (Acadvl, Acadl, Acaa2), and mitochondrial carnitine shuttle (Cpt1a, Cpt2), instigating a metabolic gene reprogramming in the heart. Induction of Ech1, Acox1, Acox3, Acsl1, and Pex11a indicated a coordinated interplay with peroxisomal β-oxidation and biogenesis mainly observed in females, suggesting sexual dimorphism in peroxisomal activation. Concurring with the sex-related changes, mitochondrial respiration rates were stronger in IUGR female fetal cardiomyocytes, accounting for enhanced adenosine 5'-triphosphate production. Mitochondrial biogenesis was induced in fetal hearts with elevated expression of Ppargc1a transcript specifically in IUGR females. Lipidomic analysis identified the accumulation of arachidonic, eicosapentaenoic, and docosapentaenoic polyunsaturated long-chain fatty acids (LCFAs) in IUGR fetal hearts, which leads to nuclear receptor peroxisome proliferator-activated receptor α (PPARα) transcriptional activation in cardiomyocytes. Also, the enrichment of H3K27ac chromatin marks to PPARα-responsive metabolic genes in IUGR fetal hearts outlines an epigenetic control in the early metabolic energy switch. CONCLUSION This study describes a premature and sex-related remodeling of cardiac metabolism in response to an unfavorable intrauterine environment, with specific LCFAs that may serve as predictive effectors leading to IUGR.
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Affiliation(s)
- Loïze Maréchal
- Department of Pharmacology & Physiology, Faculty of Medicine, Université de Montréal, Montreal, Quebec H3T 1J4, Canada
- Research Center, CHU Ste-Justine, Montréal, Quebec H3T 1C5, Canada
| | - Benoit Sicotte
- Department of Pharmacology & Physiology, Faculty of Medicine, Université de Montréal, Montreal, Quebec H3T 1J4, Canada
| | - Véronique Caron
- Research Center, CHU Ste-Justine, Montréal, Quebec H3T 1C5, Canada
| | - Michèle Brochu
- Department of Pharmacology & Physiology, Faculty of Medicine, Université de Montréal, Montreal, Quebec H3T 1J4, Canada
| | - André Tremblay
- Research Center, CHU Ste-Justine, Montréal, Quebec H3T 1C5, Canada
- Department of Obstetrics & Gynecology, Faculty of Medicine, Université de Montréal, Montreal, Quebec H3T 1J4, Canada
- Centre de Recherche en Reproduction et Fertilité, Université de Montréal, Saint-Hyacinthe, Quebec J2S 2M2, Canada
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Sicotte B, Brochu M. Fetal Sex and Fetal Environment Interact to Alter Diameter, Myogenic Tone, and Contractile Response to Thromboxane Analog in Rat Umbilical Cord Vessels. Front Physiol 2021; 12:620058. [PMID: 34603067 PMCID: PMC8481594 DOI: 10.3389/fphys.2021.620058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 08/25/2021] [Indexed: 11/29/2022] Open
Abstract
Fetal growth needs adequate blood perfusion from both sides of the placenta, on the maternal side through the uterine vessels and on the fetal side through the umbilical cord. In a model of intrauterine growth restriction (IUGR) induced by reduced blood volume expansion, uterine artery remodeling was blunted. The aim of this study is to determine if IUGR and fetus sex alter the functional and mechanical parameters of umbilical cord blood vessels. Pregnant rats were given a low sodium (IUGR) or a control diet for the last 7 days of pregnancy. Umbilical arteries and veins from term (22 day) fetal rats were isolated and set-up in wire myographs. Myogenic tone, diameter, length tension curve and contractile response to thromboxane analog U46619 and serotonin (5-HT) were measured. In arteries from IUGR fetuses, myogenic tone was increased in both sexes while diameter was significantly greater only in male fetuses. In umbilical arteries collected from the control group, the maximal contraction to U46619 was lower in females than males. Compared to the control groups, the maximal response decreased in IUGR male arteries and increased in female ones, thus abolishing the sexual dimorphism observed in the control groups. Reduced contractile response to U46619 was observed in the IUGR vein of both sexes. No difference between groups was observed in response to 5HT in arteries. In conclusion, the change in parameters of the umbilical cord blood vessels in response to a mild insult seems to show adaptation that favors better exchange of deoxygenated and wasted blood from the fetus to the placenta with increased myogenic tone.
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Affiliation(s)
- Benoit Sicotte
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Michèle Brochu
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
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Chen L, Yue J, Zhou S, Hu Y, Li J. Ouabain Protects Nephrogenesis in Rats Experiencing Intrauterine Growth Restriction and Partially Restores Renal Function in Adulthood. Reprod Sci 2021; 28:186-196. [PMID: 32767217 DOI: 10.1007/s43032-020-00280-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 07/27/2020] [Indexed: 10/23/2022]
Abstract
Intrauterine growth restriction (IUGR) is, in general, accompanied by a reduction of the nephron number, which increases the risk of hypertension and renal dysfunction. Studies have revealed that ouabain can partially restore the number of nephrons during IUGR. However, there is limited information regarding the melioration of nephric structure and function. We used maternal malnutrition to induce an IUGR model in rats. Subsequently, we used a mini-pump to administer ouabain to IUGR rats during pregnancy. Male offspring were divided randomly into two groups. One group was fed a normal diet, whereas the other was fed an isocaloric 8% high-salt diet. Maternal malnutrition led to a reduction in the birth weight and number of nephrons in offspring. At the end of a 40-week follow-up period, offspring from the IUGR group had high blood pressure and abnormal excretion of urinary protein; these parameters were exacerbated in offspring fed a high-salt diet. However, ouabain administration during pregnancy could partially restore the number of nephrons in IUGR offspring, normalize blood pressure, and reduce urinary protein excretion, even when challenged with a high-salt diet. Pathology findings revealed that IUGR, particularly following feeding of a high-salt diet, damaged the ultrastructure of glomeruli, but these harmful effects were ameliorated in offspring treated with ouabain. Collectively, our data suggest that ouabain could rescue nephrogenesis in IUGR newborns and protect (at least in part) the structure and function of the kidney during adulthood even when encountering unfavorable environmental challenges in subsequent life.
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Affiliation(s)
- Liang Chen
- Department of Gynecology, Jiangsu Province Hospital (The First Affiliated Hospital of Nanjing Medical University), 300 Guangzhou Road, Nanjing, 210000, China.
| | - Jing Yue
- Department of Obstetrics and Gynecology, Nanjing Drum Tower Hospital (The Affiliated Hospital of Nanjing University Medical School), Nanjing, China
| | - Shulin Zhou
- Department of Gynecology, Jiangsu Province Hospital (The First Affiliated Hospital of Nanjing Medical University), 300 Guangzhou Road, Nanjing, 210000, China
| | - Yali Hu
- Department of Obstetrics and Gynecology, Nanjing Drum Tower Hospital (The Affiliated Hospital of Nanjing University Medical School), Nanjing, China
| | - Juan Li
- Department of Hematology, Nanjing Drum Tower Hospital (The Affiliated Hospital of Nanjing University Medical School), Nanjing, China
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Bigonnesse E, Sicotte B, Brochu M. Activated NO pathway in uterine arteries during pregnancy in an IUGR rat model. Am J Physiol Heart Circ Physiol 2018; 315:H415-H422. [PMID: 29727218 DOI: 10.1152/ajpheart.00457.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insufficient development of the uteroplacental circulation may contribute to the development of intrauterine growth restriction (IUGR). We developed a rat model of IUGR by administering a low-Na+ diet. This diet reduces maternal blood volume expansion and uteroplacental perfusion. We hypothesized that an impaired endothelial function in radial arteries decreases vasorelaxation and lowers placental perfusion in this IUGR model. The objective was to assess radial uterine artery responses to vasoactive agents in the IUGR model versus controls. The vasoactive agents included phenylephrine and carbachol, use of a pressurized artery myograph, in the absence or presence of inhibitors of nitric oxide (NO) synthase [ N-nitro-l-arginine methyl ester (l-NAME)], cyclooxygenase (Ibuprofen), and endothelium-dependent hyperpolarization {apamin/1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole}, allowing better characterization of the mechanism implicated in endothelium-dependent relaxation. The results show that 1) the diameter of uterine radial arteries was significantly decreased in the IUGR group; 2) sensitivity to phenylephrine was reduced in IUGR arteries, which could be returned to control group values by inhibition of NO production; 3) the relaxation response to carbachol was increased in IUGR rats, principally mediated by endothelium-dependent hyperpolarization in both groups; 4) NO synthase inhibition by l-NAME decreased the maximum relaxation to carbachol only in the IUGR group; and 5) relaxation response to NO donors is increased in IUGR compared with control radial arteries. Contrary to the hypothesis, results in the IUGR model indicate that the NO pathway is activated in radial uterine arteries, most likely in compensation for the reduction in blood uteroplacental perfusion. NEW & NOTEWORTHY In contrast to genetic or surgical models of intrauterine growth restriction, the diet-induced model of reduced maternal volume expansion shows the nitric oxide pathway to be activated in the uterine artery, possibly from increased shear stress and/or placental factors.
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Affiliation(s)
- Emilie Bigonnesse
- Department of Pharmacology and Physiology, Université de Montréal , Montreal, Quebec , Canada
| | - Benoit Sicotte
- Department of Pharmacology and Physiology, Université de Montréal , Montreal, Quebec , Canada
| | - Michèle Brochu
- Department of Pharmacology and Physiology, Université de Montréal , Montreal, Quebec , Canada
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Nagel C, Trenk L, Aurich J, Wulf M, Aurich C. Changes in blood pressure, heart rate, and blood profile in mares during the last 3 months of gestation and the peripartum period. Theriogenology 2016; 86:1856-64. [PMID: 27393220 DOI: 10.1016/j.theriogenology.2016.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 10/21/2022]
Abstract
In this study, peripartum changes in complete blood count, plasma electrolyte concentrations, blood pressure, heart rate, and heart rate variability (HRV) were determined in pregnant Warmblood mares (n = 10). Blood was collected from Days 245 to 330 of gestation (phase A), 2Days 3 to 1 before foaling (phase B), repeatedly within 12 hours after foaling (phase C), and on Days 1 to 3 postpartum (phase D). On the same days as blood collection, blood pressure and cardiac beat-to-beat intervals were measured and time domain HRV variables were calculated. Blood pressure decreased during the past 3 months of gestation, reached a nadir at foaling and increased rapidly thereafter (P < 0.001). Heart rate increased in phase A, reached a maximum in phase B, and decreased directly after foaling (P < 0.001) while HRV increased transiently after foaling (P < 0.001). The number of polymorphonuclear granulocytes was higher during phases B, C, and D than that during phase A (P < 0.001) and total leukocyte numbers peaked in phase C (P < 0.001). Erythrocyte counts and hematocrit increased immediately after foaling with a rapid decrease thereafter (P < 0.001), while plasma total protein was highest 1 hour after foaling (P < 0.001). Sodium and chloride concentrations increased from phases A to C and decreased in phase D (P < 0.001). Calcium concentrations were lowest immediately after foaling. In conclusion, changes in cardiovascular function and a transient hemoconcentration occur in peripartum mares. These changes may favor adequate uterine perfusion.
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Affiliation(s)
- Christina Nagel
- Graf Lehndorff Institute for Equine Science, Vetmeduni Vienna, Neustadt/Dosse, Germany.
| | - Lisa Trenk
- Centre for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni Vienna, Vienna, Austria
| | - Jörg Aurich
- Section for Obstetrics, Gynecology and Andrology, Department for Small Animals and Horses, Vetmeduni Vienna, Vienna, Austria
| | - Manuela Wulf
- Graf Lehndorff Institute for Equine Science, Vetmeduni Vienna, Neustadt/Dosse, Germany
| | - Christine Aurich
- Centre for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni Vienna, Vienna, Austria
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Bibeau K, Sicotte B, Béland M, Bhat M, Gaboury L, Couture R, St-Louis J, Brochu M. Placental Underperfusion in a Rat Model of Intrauterine Growth Restriction Induced by a Reduced Plasma Volume Expansion. PLoS One 2016; 11:e0145982. [PMID: 26727492 PMCID: PMC4703198 DOI: 10.1371/journal.pone.0145982] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/11/2015] [Indexed: 12/20/2022] Open
Abstract
Lower maternal plasma volume expansion was found in idiopathic intrauterine growth restriction (IUGR) but the link remains to be elucidated. An animal model of IUGR was developed by giving a low-sodium diet to rats over the last week of gestation. This treatment prevents full expansion of maternal circulating volume and the increase in uterine artery diameter, leading to reduced placental weight compared to normal gestation. We aimed to verify whether this is associated with reduced remodeling of uteroplacental circulation and placental hypoxia. Dams were divided into two groups: IUGR group and normal-fed controls. Blood velocity waveforms in the main uterine artery were obtained by Doppler sonography on days 14, 18 and 21 of pregnancy. On day 22 (term = 23 days), rats were sacrificed and placentas and uterine radial arteries were collected. Diameter and myogenic response of uterine arteries supplying placentas were determined while expression of hypoxia-modulated genes (HIF-1α, VEGFA and VEGFR2), apoptotic enzyme (Caspase -3 and -9) and glycogen cells clusters were measured in control and IUGR term-placentas. In the IUGR group, impaired blood velocity in the main uterine artery along with increased resistance index was observed without alteration in umbilical artery blood velocity. Radial uterine artery diameter was reduced while myogenic response was increased. IUGR placentas displayed increased expression of hypoxia markers without change in the caspases and increased glycogen cells in the junctional zone. The present data suggest that reduced placental and fetal growth in our IUGR model may be mediated, in part, through reduced maternal uteroplacental blood flow and increased placental hypoxia.
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Affiliation(s)
- Karine Bibeau
- Department of Molecular and Integrative Physiology, Université de Montréal, Montréal, Québec, Canada
| | - Benoit Sicotte
- Department of Molecular and Integrative Physiology, Université de Montréal, Montréal, Québec, Canada
| | - Mélanie Béland
- Department of Pathology and Cellular Biology, Université de Montréal, Montréal, Québec, Canada
| | - Menakshi Bhat
- Department of Molecular and Integrative Physiology, Université de Montréal, Montréal, Québec, Canada
| | - Louis Gaboury
- Department of Pathology and Cellular Biology, Université de Montréal, Montréal, Québec, Canada
| | - Réjean Couture
- Department of Molecular and Integrative Physiology, Université de Montréal, Montréal, Québec, Canada
| | - Jean St-Louis
- Department of Obstetrics-Gynecology, Université de Montréal, Montréal, Québec, Canada
| | - Michèle Brochu
- Department of Molecular and Integrative Physiology, Université de Montréal, Montréal, Québec, Canada
- * E-mail:
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Vaswani K, Chan HW, Verma P, Dekker Nitert M, Peiris HN, Wood-Bradley RJ, Armitage JA, Rice GE, Mitchell MD. The rat placental renin-angiotensin system - a gestational gene expression study. Reprod Biol Endocrinol 2015; 13:89. [PMID: 26260700 PMCID: PMC4532142 DOI: 10.1186/s12958-015-0088-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/03/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The placenta is an essential organ that provides nutrients and oxygen to the developing fetus and removes toxic waste products from the fetal circulation. Maintaining placental blood osmotic pressure and blood flow is crucial for viable offspring. The renin-angiotensin system (RAS) in the placenta is a key player in the regulation of maternal-fetal blood flow during pregnancy. Therefore, the aim of this study was to determine if RAS genes are differentially expressed in mid to late gestation in rat placenta. METHODS Whole placental tissue samples from pregnant Sprague Dawley rats at embryonic (E) days 14.25, 15.25, 17.25 and 20 (n = 6 for each gestational age) were used for genome-wide gene expression by microarray. RAS genes with expression differences of >2 fold were further analyzed. Quantitative Real-Time PCR (qPCR) was performed on independent samples to confirm and validate microarray data. Immunohistochemisty and Western blotting were performed on a differentially expressed novel RAS pathway gene (ANPEP). RESULTS Six out of 17 genes of the RAS pathway were differentially expressed at different gestational ages. Gene expression of four genes (Angiotensin converting enzyme (Ace), angiotensin converting enzyme 2 (Ace2), membrane metalloendopeptidase (Mme) and angiotensin II receptor 1A (Agtr1a)) were significantly upregulated at E20 whereas two others (Thimet oligopeptidase 1 (Thop1) and Alanyl aminopeptidase (Anpep)) were downregulated at E20 prior to the onset of labour. These changes were confirmed by qPCR. Western blots revealed no overall differences in ANPEP protein expression in the placentae. Immunohistochemical studies, however, indicated that the localization of ANPEP differed at E17.25 and E20 as ANPEP localization in the giant trophoblast cell of the junctional zone was no longer detectable at E20. CONCLUSIONS The current study investigated the expression of members of the RAS pathway in rat placentae and observed significantly altered expression of 6 RAS genes at 4 gestational ages. These findings present the need for further comprehensive investigation of RAS genes in normal and complicated pregnancies.
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Affiliation(s)
- Kanchan Vaswani
- Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research Royal Brisbane and Women's Hospital Campus, Building 71/918, Royal Brisbane Hospital, Herston, QLD, 4029, Australia.
| | - Hsiu-Wen Chan
- Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research Royal Brisbane and Women's Hospital Campus, Building 71/918, Royal Brisbane Hospital, Herston, QLD, 4029, Australia.
| | - Pali Verma
- Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research Royal Brisbane and Women's Hospital Campus, Building 71/918, Royal Brisbane Hospital, Herston, QLD, 4029, Australia.
| | - Marloes Dekker Nitert
- Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research Royal Brisbane and Women's Hospital Campus, Building 71/918, Royal Brisbane Hospital, Herston, QLD, 4029, Australia.
| | - Hassendrini N Peiris
- Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research Royal Brisbane and Women's Hospital Campus, Building 71/918, Royal Brisbane Hospital, Herston, QLD, 4029, Australia.
| | - Ryan J Wood-Bradley
- Department of Anatomy & Developmental Biology Monash University, Clayton, VIC, 3800, Australia.
- School of Medicine (Optometry), Deakin University, Pigdons Road, Waurn Ponds, VIC, 3800, Australia.
| | - James A Armitage
- Department of Anatomy & Developmental Biology Monash University, Clayton, VIC, 3800, Australia.
- School of Medicine (Optometry), Deakin University, Pigdons Road, Waurn Ponds, VIC, 3800, Australia.
| | - Gregory E Rice
- Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research Royal Brisbane and Women's Hospital Campus, Building 71/918, Royal Brisbane Hospital, Herston, QLD, 4029, Australia.
| | - Murray D Mitchell
- Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research Royal Brisbane and Women's Hospital Campus, Building 71/918, Royal Brisbane Hospital, Herston, QLD, 4029, Australia.
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West CA, Shaw S, Sasser JM, Fekete A, Alexander T, Cunningham MW, Masilamani SME, Baylis C. Chronic vasodilation increases renal medullary PDE5A and α-ENaC through independent renin-angiotensin-aldosterone system pathways. Am J Physiol Regul Integr Comp Physiol 2013; 305:R1133-40. [PMID: 24068049 PMCID: PMC3841800 DOI: 10.1152/ajpregu.00003.2013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 09/19/2013] [Indexed: 02/05/2023]
Abstract
We have previously observed that many of the renal and hemodynamic adaptations seen in normal pregnancy can be induced in virgin female rats by chronic systemic vasodilation. Fourteen-day vasodilation with sodium nitrite or nifedipine (NIF) produced plasma volume expansion (PVE), hemodilution, and increased renal medullary phosphodiesterase 5A (PDE5A) protein. The present study examined the role of the renin-angiotensin-aldosterone system (RAAS) in this mechanism. Virgin females were treated for 14 days with NIF (10 mg·kg(-1)·day(-1) via diet), NIF with spironolactone [SPR; mineralocorticoid receptor (MR) blocker, 200-300 mg·kg(-1)·day(-1) via diet], NIF with losartan [LOS; angiotensin type 1 (AT1) receptor blocker, 20 mg·kg(-1)·day(-1) via diet], enalapril (ENAL; angiotensin-converting enzyme inhibitor, 62.5 mg/l via water), or vehicle (CON). Mean arterial pressure (MAP) was reduced 7.4 ± 0.5% with NIF, 6.33 ± 0.5% with NIF + SPR, 13.3 ± 0.9% with NIF + LOS, and 12.0 ± 0.4% with ENAL vs. baseline MAP. Compared with CON (3.6 ± 0.3%), plasma volume factored for body weight was increased by NIF (5.2 ± 0.4%) treatment but not by NIF + SPR (4.3 ± 0.3%), NIF + LOS (3.6 ± 0.1%), or ENAL (4.0 ± 0.3%). NIF increased PDE5A protein abundance in the renal inner medulla, and SPR did not prevent this increase (188 ± 16 and 204 ± 22% of CON, respectively). NIF increased the α-subunit of the epithelial sodium channel (α-ENaC) protein in renal outer (365 ± 44%) and inner (526 ± 83%) medulla, and SPR prevented these changes. There was no change in either PDE5A or α-ENaC abundance vs. CON in rats treated with NIF + LOS or ENAL. These data indicate that the PVE and renal medullary adaptations in response to chronic vasodilation result from RAAS signaling, with increases in PDE5A mediated through AT1 receptor and α-ENaC through the MR.
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Affiliation(s)
- Crystal A West
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
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Maternal high-sodium intake alters the responsiveness of the renin–angiotensin system in adult offspring. Life Sci 2012; 90:785-92. [DOI: 10.1016/j.lfs.2012.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 03/16/2012] [Accepted: 04/03/2012] [Indexed: 01/13/2023]
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Cornock R, Langley-Evans SC, Mobasheri A, McMullen S. The impact of maternal protein restriction during rat pregnancy upon renal expression of angiotensin receptors and vasopressin-related aquaporins. Reprod Biol Endocrinol 2010; 8:105. [PMID: 20807409 PMCID: PMC2940793 DOI: 10.1186/1477-7827-8-105] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 08/31/2010] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Maternal protein restriction during rat pregnancy is known to impact upon fetal development, growth and risk of disease in later life. It is of interest to understand how protein undernutrition influences the normal maternal adaptation to pregnancy. Here we investigated the mechanisms regulating renal haemodynamics and plasma volume during pregnancy, in the context of both normal and reduced plasma volume expansion. The study focused on expression of renal angiotensin receptors (ATR) and vasopressin-related aquaporins (AQP), hypothesising that an alteration in the balance of these proteins would be associated with pregnancy per se and with compromised plasma volume expansion in rats fed a low-protein diet. METHODS Female Wistar rats were mated and fed a control (18% casein) or low-protein (9% casein) diet during pregnancy. Animals were anaesthetised on days 5, 10, 15 and 20 of gestation (n = 8/group/time-point) for determination of plasma volume using Evans Blue dye, prior to euthanasia and collection of tissues. Expression of the ATR subtypes and AQP2, 3 and 4 were assessed in maternal kidneys by PCR and western blotting. 24 non-pregnant Wistar rats underwent the same procedure at defined points of the oestrous cycle. RESULTS As expected, pregnancy was associated with an increase in blood volume and haemodilution impacted upon red blood cell counts and haemoglobin concentrations. Expression of angiotensin II receptors and aquaporins 2, 3 and 4 was stable across all stages of the oestrus cycle. Interesting patterns of intra-renal protein expression were observed in response to pregnancy, including a significant down-regulation of AQP2. In contrast to previous literature and despite an apparent delay in blood volume expansion in low-protein fed rats, blood volume did not differ significantly between groups of pregnant animals. However, a significant down-regulation of AT2R protein expression was observed in low-protein fed animals alongside a decrease in creatinine clearance. CONCLUSION Regulatory systems involved in the pregnancy-induced plasma volume expansion are susceptible to the effects of maternal protein restriction.
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Affiliation(s)
- Ruth Cornock
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - Simon C Langley-Evans
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - Ali Mobasheri
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - Sarah McMullen
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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West C, Zhang Z, Ecker G, Masilamani SME. Increased renal alpha-epithelial sodium channel (ENAC) protein and increased ENAC activity in normal pregnancy. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1326-32. [PMID: 20686170 DOI: 10.1152/ajpregu.00082.2010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pregnancy-mediated sodium (Na) retention is required to provide an increase in plasma volume for the growing fetus. The mechanisms responsible for this Na retention are not clear. We first used a targeted proteomics approach and found that there were no changes in the protein abundance compared with virgin rats of the β or γ ENaC, type 3 Na(+)/H(+) exchanger (NHE3), bumetanide-sensitive cotransporter (NKCC2), or NaCl cotransporter (NCC) in mid- or late pregnancy. In contrast, we observed marked increases in the abundance of the α-ENaC subunit. The plasma volume increased progressively during pregnancy with the greatest plasma volume being evident in late pregnancy. ENaC inhibition abolished the difference in plasma volume status between virgin and pregnant rats. To determine the in vivo activity of ENaC, we conducted in vivo studies of rats in late pregnancy (days 18-20) and virgin rats to measure the natriuretic response to ENaC blockade (with benzamil). The in vivo activity of ENaC (U(Na)V postbenzamil-U(Na)V postvehicle) was markedly increased in late pregnancy, and this difference was abolished by pretreatment with the mineralocorticoid receptor antagonist, eplerenone. These findings demonstrate that the increased α-ENaC subunit of pregnancy is associated with an mineralocorticoid-dependent increase in ENaC activity. Further, we show that ENaC activity is a major contributor of plasma volume status in late pregnancy. These changes are likely to contribute to the renal sodium retention and plasma volume expansion required for an optimal pregnancy.
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Affiliation(s)
- Crystal West
- Department of Internal Medicine/Division of Nephrology, Virginia Commonwealth University Medical Center, Richmond, Virginia 23298-0160, USA
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Bibeau K, Battista MC, Houde V, Brochu M. Fetal adrenal gland alterations in a rat model of adverse intrauterine environment. Am J Physiol Regul Integr Comp Physiol 2009; 298:R899-911. [PMID: 19923365 DOI: 10.1152/ajpregu.00238.2009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
By feeding a low-sodium diet to dams over the last third of gestation, we have developed an animal model of intrauterine growth restriction (IUGR). Given that fetal adrenal development and maturation occur during late gestation in rats, the aim of this study was to evaluate the expression of proteins and enzymes involved in steroidogenesis and catecholamine synthesis in adrenal glands from IUGR fetuses. A gene microarray was performed to investigate for alteration in the pathways participating in hormone production. Results show that increased aldosterone serum concentrations in IUGR fetuses were associated with higher mRNA adrenal levels of angiotensin II receptor type 1 (AT(1)R) and cytochrome P450 aldosterone synthase in response to decreased serum sodium content. Conversely, reduced serum corticosterone concentrations in these fetuses appear to result from alterations in gene expression involved in cholesterol metabolism, such as the augmented apolipoprotein E levels, and in steroidogenesis, like the decreased levels of cytochrome P45011beta-hydroxylase. Furthermore, increased AT(2)R expression and the presence of hypoxia and oxidative stress may, in turn, explain the higher adrenal mRNA levels of enzymes involved in catecholamine synthesis. Despite this increase, catecholamine adrenal content was reduced in males and was similar in females compared with sex-matched controls, suggesting higher catecholamine secretion. This could be associated with the induction of genes involved in inflammation-related, acute-phase response in IUGR fetuses. All of these alterations could have long-lasting health effects and may, hence, be implicated in the pathogenesis of increased blood pressure and cardiac hypertrophy observed in IUGR adult animals from this model.
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Affiliation(s)
- Karine Bibeau
- Research Centre, Centre Hospitalier Universitaire Sainte-Justine, 3175 Côte Ste-Catherine, Montréal, QC, Canada H3T 1C5
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Vieira-Filho LD, Lucena-Jnior JM, Barreto IS, Angelim JL, Paixo AD. Repercussion of acetylsalicylic acid during fetal development on later renal hemodynamics of rats. Fundam Clin Pharmacol 2008; 22:379-86. [DOI: 10.1111/j.1472-8206.2008.00604.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Leandro SM, Furukawa LNS, Shimizu MHM, Casarini DE, Seguro AC, Patriarca G, Coelho MS, Dolnikoff MS, Heimann JC. Low birth weight in response to salt restriction during pregnancy is not due to alterations in uterine-placental blood flow or the placental and peripheral renin-angiotensin system. Physiol Behav 2008; 95:145-51. [PMID: 18572207 DOI: 10.1016/j.physbeh.2008.05.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 05/12/2008] [Accepted: 05/13/2008] [Indexed: 11/25/2022]
Abstract
A number of studies conducted in humans and in animals have observed that events occurring early in life are associated with the development of diseases in adulthood. Salt overload and restriction during pregnancy and lactation are responsible for functional (hemodynamic and hormonal) and structural alterations in adult offspring. Our group observed that lower birth weight and insulin resistance in adulthood is associated with salt restriction during pregnancy. On the other hand, perinatal salt overload is associated with higher blood pressure and higher renal angiotensin II content in adult offspring. Therefore, we hypothesised that renin-angiotensin system (RAS) function is altered by changes in sodium intake during pregnancy. Such changes may influence fetoplacental blood flow and thereby fetal nutrient supply, with effects on growth in utero and, consequently, on birth weight. Female Wistar rats were fed low-salt (LS), normal-salt (NS), or high-salt (HS) diet, starting before conception and continuing until day 19 of pregnancy. Blood pressure, heart rate, fetuses and dams' body weight, placentae weight and litter size were measured on day 19 of pregnancy. Cardiac output, uterine and placental blood flow were also determined on day 19. Expressions of renin-angiotensin system components and of the TNF-alpha gene were evaluated in the placentae. Plasma renin activity (PRA) and plasma and tissue angiotensin-converting enzyme (ACE) activity, as well as plasma and placental levels of angiotensins I, II, and 1-7 were measured. Body weight and kidney mass were greater in HS than in NS and LS dams. Food intake did not differ among the maternal groups. Placental weight was lower in LS dams than in NS and HS dams. Fetal weight was lower in the LS group than in the NS and HS groups. The PRA was greater in LS dams than in NS and HS dams, although ACE activity (serum, cardiac, renal, and placental) was unaffected by the level of sodium intake. Placental levels of angiotensins I and II were lower in the HS group than in the NS and LS groups. Placental angiotensin receptor type 1 (AT(1)) gene expression and levels of thiobarbituric acid reactive substances (TBARS) were higher in HS dams, as were uterine blood flow and cardiac output. The degree of salt intake did not influence plasma sodium, potassium or creatinine. Although fractional sodium excretion was higher in HS dams than in NS and LS dams, fractional potassium excretion was unchanged. In conclusion, findings from this study indicate that the reduction in fetal weight in response to salt restriction during pregnancy does not involve alterations in uterine-placental perfusion or the RAS. Moreover, no change in fetal weight is observed in response to salt overload during pregnancy. However, salt overload did lead to an increase in placental weight and uterine blood flow associated with alterations in maternal plasma and placental RAS. Therefore, these findings indicate that changes in salt intake during pregnancy lead to alterations in uterine-placental perfusion and fetal growth.
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Affiliation(s)
- Sandra Márcia Leandro
- Department of Internal Medicine, Laboratory of Experimental Hypertension, University of São Paulo School of Medicine, São Paulo, Brazil
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Angiotensin II (Ang II) evoked secretion of the human placental lactogen (HPL) in intrauterine growth retardation: examination of the relationship with Ang II receptor type 1 (AT1) expression. Int Immunopharmacol 2007; 8:177-81. [PMID: 18182223 DOI: 10.1016/j.intimp.2007.08.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 08/30/2007] [Accepted: 08/31/2007] [Indexed: 11/18/2022]
Abstract
Angiotensin II (Ang II) and its hemodynamic effects on placental vasculature mediated via Ang II receptor type 1 (AT1) may play significant role in intrauterine growth retardation (IUGR). Placental lactogen (HPL) production directly reflects placental function. We compared influence of Ang II on HPL production in normal and IUGR-complicated pregnancies and correlated this phenomenon with AT1 expression. Basal and Ang II-evoked HPL secretion was examined in perfused placental lobules using ELISA. After immunostaining of placental sections, AT1 expression was estimated using quantitative morphometry. Ang II increased HPL secretion. Ang II-evoked increase in HPL concentration in the perfusion fluid was 27.36+/-6.4 (%, +/-SEM) lower in IUGR (p<0.05) compared to normal-course pregnancies. AT1 expression was significantly decreased in IUGR and was 78.12+/-8.2 (%, +/-SEM) of the mean value of controls. Demonstrating that Ang II-evoked secretion of HPL in preeclampsia-free IUGR is decreased and correlates with down-regulated expression of AT1, we present a new approach to the pathophysiology of IUGR.
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