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Martínez N, Damiano AE. Aquaporins in Fetal Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1398:251-266. [PMID: 36717499 DOI: 10.1007/978-981-19-7415-1_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Water homeostasis is essential for fetal growth, and it depends on the successful development of the placenta. Many aquaporins (AQPs) were identified from blastocyst stages to term placenta. In the last years, cytokines, hormones, second messengers, intracellular pH, and membrane proteins were found to regulate their expression and function in the human placenta and fetal membranes. Accumulated data suggest that these proteins may be involved not only in the maintenance of the amniotic fluid volume homeostasis but also in the development of the placenta and fetal organs. In this sense, dysregulation of placental AQPs is associated with gestational disorders. Thus, current evidence shows that AQPs may collaborate in cellular events including trophoblast migration and apoptosis. In addition, aquaglyceroporins are involved in energy metabolism as well as urea elimination across the placenta. In the last year, the presence of AQP9 in trophoblast mitochondria opened new hypotheses about its role in pregnancy. However, much further work is needed to understand the importance of these proteins in human pregnancies.
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Affiliation(s)
- Nora Martínez
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-CONICET-Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alicia E Damiano
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-CONICET-Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Cátedra de Biología Celulary Molecular, Departamento de Ciencias Biológicas. Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Slagle C, Gist KM, Starr MC, Hemmelgarn TS, Goldstein SL, Kent AL. Fluid Homeostasis and Diuretic Therapy in the Neonate. Neoreviews 2022; 23:e189-e204. [PMID: 35229135 DOI: 10.1542/neo.23-3-e189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Understanding physiologic water balance and homeostasis mechanisms in the neonate is critical for clinicians in the NICU as pathologic fluid accumulation increases the risk for morbidity and mortality. In addition, once this process occurs, treatment is limited. In this review, we will cover fluid homeostasis in the neonate, explain the implications of prematurity on this process, discuss the complexity of fluid accumulation and the development of fluid overload, identify mitigation strategies, and review treatment options.
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Affiliation(s)
- Cara Slagle
- Division of Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, College of Medicine, Cincinnati, OH
| | - Katja M Gist
- Division of Cardiology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, College of Medicine, Cincinnati, OH
| | - Michelle C Starr
- Division of Pediatric Nephrology, Department of Pediatrics, Indiana University School of Medicine and Riley Hospital for Children, Indianapolis, IN
| | - Trina S Hemmelgarn
- Division of Pharmacology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, College of Pharmacy, Cincinnati, OH
| | - Stuart L Goldstein
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center and the University of Cincinnati, College of Medicine, Cincinnati, OH
| | - Alison L Kent
- Department of Pediatrics, University of Rochester, NY, and Australian National University Medical School, Canberra, ACT, Australia
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Abstract
Aquaporins (AQPs) are water channels proteins that facilitate water flux across cell membranes in response to osmotic gradients. Despite of the differences in the mammalian placentas, the conserved combination of AQPs expressed in placental and fetal membranes throughout gestation suggests that these proteins may be important in the regulation of fetal water homeostasis. Thus, AQPs may regulate the amniotic fluid volume and participate in the trans-placental transfer of water. Apart from their classical roles, recent studies have revealed that placental AQPs may also cooperate in cellular processes such as the migration and the apoptosis of the trophoblasts. Aquaglyceroporins can also participate in the energy metabolism and in the urea elimination across the placenta. Many factors including oxygen, hormones, acid-basis homeostasis, maternal dietary status, interaction with other transport proteins and osmotic stress are proposed to regulate their expression and function during gestation and alterations result in pathological pregnancies.
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Affiliation(s)
- Alicia E Damiano
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-CONICET-Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina; Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Szpilbarg N, Martínez NA, Di Paola M, Reppetti J, Medina Y, Seyahian A, Castro Parodi M, Damiano AE. New Insights Into the Role of Placental Aquaporins and the Pathogenesis of Preeclampsia. Front Physiol 2018; 9:1507. [PMID: 30425647 PMCID: PMC6218616 DOI: 10.3389/fphys.2018.01507] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 10/08/2018] [Indexed: 01/24/2023] Open
Abstract
Accumulated evidence suggests that an abnormal placentation and an altered expression of a variety of trophoblast transporters are associated to preeclampsia. In this regard, an abnormal expression of AQP3 and AQP9 was reported in these placentas. Recent data suggests that placental AQPs are not only water channel proteins and that may participate in relevant processes required for a normal placental development, such as cell migration and apoptosis. Recently we reported that a normal expression of AQP3 is required for the migration of extravillous trophoblast (EVT) cells. Thus, alterations in this protein might lead to an insufficient transformation of the maternal spiral arteries resulting in fluctuations of oxygen tension, a potent stimulus for oxidative damage and trophoblast apoptosis. In this context, the increase of oxygen and nitrogen reactive species could nitrate AQP9, producing the accumulation of a non-functional protein affecting the survival of the villous trophoblast (VT). This may trigger the exacerbated release of apoptotic VT fragments into maternal circulation producing the systemic endothelial dysfunction underlying the maternal syndrome. Therefore, our hypothesis is that the alteration in the expression of placental AQPs observed at the end of gestation may take place during the trophoblast stem cell differentiation, disturbing both EVT and VT cells development, or during the VT differentiation and turnover. In both situations, VT is affected and at last the maternal vascular system is activated leading to the clinical manifestations of preeclampsia.
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Affiliation(s)
- Natalia Szpilbarg
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nora A Martínez
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mauricio Di Paola
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.,Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Julieta Reppetti
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Yollyseth Medina
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Abril Seyahian
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mauricio Castro Parodi
- Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alicia E Damiano
- Laboratorio de Biología de la Reproducción, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO)-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.,Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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Banciu DD, Banciu A, Radu BM. Electrophysiological Features of Telocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 913:287-302. [PMID: 27796895 DOI: 10.1007/978-981-10-1061-3_19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Telocytes (TCs) are interstitial cells described in multiple structures, including the gastrointestinal tract, respiratory tract, urinary tract, uterus, and heart. Several studies have indicated the possibility that TCs are involved in the pacemaker potential in these organs. It is supposed that TCs are interacting with the neighboring muscular cells and their network contributes to the initiation and propagation of the electrical potentials. In order to understand the contribution of TCs to various excitability mechanisms, it is necessary to analyze the plasma membrane proteins (e.g., ion channels) functionally expressed in these cells. So far, potassium, calcium, and chloride currents, but not sodium currents, have been described in TCs in primary cell culture from different tissues. Moreover, TCs have been described as sensors for mechanical stimuli (e.g., contraction, extension, etc.). In conclusion, TCs might play an essential role in gastrointestinal peristalsis, in respiration, in pregnant uterus contraction, or in miction, but further highlighting studies are necessary to understand the molecular mechanisms and the cell-cell interactions by which TCs contribute to the tissue excitability and pacemaker potentials initiation/propagation.
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Affiliation(s)
- Daniel Dumitru Banciu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Bucharest, 050095, Romania
| | - Adela Banciu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Bucharest, 050095, Romania
| | - Beatrice Mihaela Radu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Bucharest, 050095, Romania. .,Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 8, Verona, 37134, Italy.
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Jiang SS, Zhu XJ, Ding SD, Wang JJ, Jiang LL, Jiang WX, Zhu XQ. Expression and Localization of Aquaporins 8 and 9 in Term Placenta With Oligohydramnios. Reprod Sci 2012; 19:1276-84. [DOI: 10.1177/1933719112450328] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Shan-Shan Jiang
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
| | - Xue-Jie Zhu
- Department of Obstetrics and Gynecology, the First Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
| | - Sheng-Di Ding
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
| | - Jing-Jing Wang
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
| | - Ling-Ling Jiang
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
| | - Wen-Xiao Jiang
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
| | - Xue-Qiong Zhu
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
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Expression of aquaporin water channels in canine fetal adnexa in respect to the regulation of amniotic fluid production and absorption. Placenta 2012; 33:502-10. [PMID: 22425592 DOI: 10.1016/j.placenta.2012.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 02/20/2012] [Accepted: 02/22/2012] [Indexed: 01/24/2023]
Abstract
Amniotic fluid (AF) is created by the flow of fluid from the fetal lung and bladder and reabsorbed in part by fetal swallowing and partly by the transfer across the amnion to the fetal circulation. Placental water flux is an important factor in determining AF volume and fetal hydration. In addition the fetal membranes might be involved in the regulation of fluid composition. To understand the mechanisms responsible for maintaining a correct balance of AF volume we evaluated the expression of aquaporins (AQPs) in canine fetal adnexa. AQPs are a family of integral membrane proteins permitting passive but physiologically rapid transcellular water movement. The presence of AQP1, 3, 5, 8 and -9 was immunohistochemically assessed in canine fetal adnexa, collected in early, middle and late-gestation during ovario-hysterectomies performed with fully informed owners' consent. Changes in AF volume and biochemical composition were also evaluated throughout pregnancy. Our results show distinct aquaporin expression patterns in maternal and extraembryonic tissues in relation to pregnancy period. AQP1 was localized in placental endothelia, allantochorion, amnion, allantois and yolk sac. AQP3 was present in the placental labyrinth, amnion, allantois and yolk sac. AQP8 was especially evident on the epithelia lining the glandular chambers, the amniotic and allantois sacs. AQP9, a channel highly permeable to water and urea, was observed in epithelia of amnion, allantois and yolk sac. In summary, AQP1, 3, 5, 8 and -9 have distinct expression patterns in canine fetal membranes and placenta in relation to pregnancy period, suggesting an involvement in mediating the AF changes during gestation.
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Damiano AE. Review: Water channel proteins in the human placenta and fetal membranes. Placenta 2011; 32 Suppl 2:S207-11. [PMID: 21208655 DOI: 10.1016/j.placenta.2010.12.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 12/09/2010] [Accepted: 12/09/2010] [Indexed: 11/27/2022]
Abstract
It has been established that the permeability of the human placenta increases with advancing gestation. Indirect evidence has also proposed that aquaporins (AQPs) may be involved in the regulation of placental water flow but the mechanisms are poorly understood. Five AQPs have been found in the human placenta and fetal membranes [AQP1, 3, 4, 8 and 9]. However, the physiological function(s) and the regulation of these proteins remain unknown. Emerging evidence has shown that human fetal membrane AQPs may have a role in intramembranous amniotic fluid water regulation and that alterations in their expression are related to polyhydramnios and oligohydramnios. In addition, we have observed a high expression of AQP3 and AQP9 in the apical membrane of the syncytiotrophoblast. Moreover, AQP9 was found to be increased in preeclamptic placentas, but it could not be related to its functionality for the transport of water and mannitol. However, a significant urea flux was seen. Since preeclampsia is not known to be associated with an altered water flux to the fetus we propose that AQP9 might not have a key role in water transport in human placenta, but a function in the energy metabolism or the urea uptake and elimination across the placenta. However, the role of AQP9 in human placenta is still speculative and needs further studies. Insulin, hCG, cAMP and CFTR have been found to be involved in the regulation of the molecular and functional expression of AQPs. Further insights into these mechanisms may clarify how water moves between the mother and the fetus.
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Affiliation(s)
- A E Damiano
- Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Zhu X, Jiang S, Hu Y, Zheng X, Zou S, Wang Y, Zhu X. The expression of aquaporin 8 and aquaporin 9 in fetal membranes and placenta in term pregnancies complicated by idiopathic polyhydramnios. Early Hum Dev 2010; 86:657-63. [PMID: 20732771 DOI: 10.1016/j.earlhumdev.2010.07.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 07/04/2010] [Accepted: 07/11/2010] [Indexed: 11/28/2022]
Abstract
BACKGROUND Aquaporins are a family of membrane-bound water channel proteins that regulate the flow of water across a variety of biological membranes. The expression of aquaporin 8 and aquaporin 9 has been demonstrated in human chorioamniotic membrane and placenta. But their roles in the pathophysiology of polyhydramnios are unclear. AIMS To study the expression of aquaporin 8 and aquaporin 9 in fetal membranes and placenta in term pregnancies complicated by idiopathic polyhydramnios and to explore the association between aquaporin expressions and polyhydramnios. SUBJECTS The placentas were collected from 51 patients who underwent elective Cesarean sections at term, of which 21 cases had idiopathic polyhydramnios and the other 30 had normal amniotic fluid volume. OUTCOME MEASURES Real-time polymerase chain reaction and immunohistochemistry techniques were used to determine the expression and localization of aquaporin 8 and aquaporin 9 in the amnion, chorion and placenta. RESULTS Expression of aquaporin 8 and aquaporin 9 was detected in the amnion, chorion and placenta and located in amnion epithelia, chorion cytotrophoblasts and placental trophoblast. Compared to normal amniotic fluid volume group, the expression of aquaporin 8 in amnion, and aquaporin 9 in amnion and chorion, were significantly increased in idiopathic polyhydramnios group; however, their expression in the placenta was significantly decreased. CONCLUSIONS When polyhydramnios occurs, expression of aquaporin 8 and aquaporin 9 in fetal membranes and placenta is an adaptive change, which may be involved in the regulation of amniotic fluid volume. However, the modulation factors of the aquaporin 8 and aquaporin 9 expressions need further study.
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Affiliation(s)
- Xueqiong Zhu
- Department of Obstetrics and Gynecology, the Second Affiliated Hospital of Wenzhou Medical College, Wenzhou 325027, China.
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Zhu X, Jiang S, Zhu X, Zou S, Wang Y, Hu Y. Expression of Aquaporin 1 and Aquaporin 3 in Fetal Membranes and Placenta in Human Term Pregnancies with Oligohydramnios. Placenta 2009; 30:670-6. [DOI: 10.1016/j.placenta.2009.05.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 05/20/2009] [Accepted: 05/23/2009] [Indexed: 11/30/2022]
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CFTR May Modulate AQP9 Functionality in Preeclamptic Placentas. Placenta 2009; 30:642-8. [DOI: 10.1016/j.placenta.2009.04.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 03/27/2009] [Accepted: 04/29/2009] [Indexed: 11/23/2022]
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Abstract
Water arrives in the mammalian gestation from the maternal circulation across the placenta. It then circulates between the fetal water compartments, including the fetal body compartments, the placenta and the amniotic fluid. Amniotic fluid is created by the flow of fluid from the fetal lung and bladder. A major pathway for amniotic fluid resorption is fetal swallowing; however, in many cases the amounts of fluid produced and absorbed do not balance. A second resorption pathway, the intramembranous pathway (across the amnion to the fetal circulation), has been proposed to explain the maintenance of normal amniotic fluid volume. Amniotic fluid volume is thus a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion. Water flux across biologic membranes may be driven by osmotic or hydrostatic forces; existing data suggest that intramembranous flow in humans is driven by the osmotic difference between the amniotic fluid and the fetal serum. The driving force for placental flow is more controversial, and both forces may be in effect. The mechanism(s) responsible for regulating water flow to and from the amniotic fluid is unknown. In other parts of the body, notably the kidney, water flux is regulated by the expression of aquaporin water channels on the cell membrane. We hypothesize that aquaporins have a role in regulating water flux across both the amnion and the placenta, and present evidence in support of this theory. Current knowledge of gestational water flow is sufficient to allow prediction of fetal outcome when water flow is abnormal, as in twin-twin transfusion syndrome. Further insight into these mechanisms may allow novel treatments for amniotic fluid volume abnormalities with resultant improvement in clinical outcome.
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Affiliation(s)
- M H Beall
- Department of Obstetrics and Gynecology, Harbor-UCLA Medical Center, 1000 W. Carson Street, Box 3, Torrance, CA 90502, USA.
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Beall MH, van den Wijngaard JPHM, van Gemert MJC, Ross MG. Amniotic fluid water dynamics. Placenta 2007; 28:816-23. [PMID: 17254633 DOI: 10.1016/j.placenta.2006.11.009] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Revised: 11/28/2006] [Accepted: 11/30/2006] [Indexed: 11/27/2022]
Abstract
Water arrives in the mammalian gestation from the maternal circulation across the placenta. It then circulates between the fetal water compartments, including the fetal body compartments, the placenta and the amniotic fluid. Amniotic fluid is created by the flow of fluid from the fetal lung and bladder. A major pathway for amniotic fluid resorption is fetal swallowing; however in many cases the amounts of fluid produced and absorbed do not balance. A second resorption pathway, the intramembranous pathway (across the amnion to the fetal circulation), has been proposed to explain the maintenance of normal amniotic fluid volume. Amniotic fluid volume is thus a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion. Membrane water flux is a function of the water permeability of the membrane; available data suggests that the amnion is the structure limiting intramembranous water flow. In the placenta, the syncytiotrophoblast is likely to be responsible for limiting water flow across the placenta. In human tissues, placental trophoblast membrane permeability increases with gestational age, suggesting a mechanism for the increased water flow necessary in late gestation. Membrane water flow can be driven by both hydrostatic and osmotic forces. Changes in both osmotic/oncotic and hydrostatic forces in the placenta my alter maternal-fetal water flow. A normal amniotic fluid volume is critical for normal fetal growth and development. The study of amniotic fluid volume regulation may yield important insights into the mechanisms used by the fetus to maintain water homeostasis. Knowledge of these mechanisms may allow novel treatments for amniotic fluid volume abnormalities with resultant improvement in clinical outcome.
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Affiliation(s)
- M H Beall
- Department of Obstetrics and Gynecology, Harbor-UCLA Medical Center, 1000 W. Carson St., Box 3, Torrance, CA 90502, USA.
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Placental and membrane aquaporin water channels: correlation with amniotic fluid volume and composition. Placenta 2006; 28:421-8. [PMID: 16870248 DOI: 10.1016/j.placenta.2006.06.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 05/19/2006] [Accepted: 06/02/2006] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To assess the role of aquaporins (AQPs) in the regulation of amniotic fluid (AF) volume, we determined AF volume and composition and placental and fetal membrane AQP expression throughout the second half of murine gestation. METHODS Pregnant CD1 mice were sacrificed at e10-19 and AF volume and composition determined. Placenta and fetal membranes were screened for AQP gene expression. AQP gene expression was quantified by real-time RT PCR and protein location determined by immunohistochemistry. Changes in AF volume were correlated with AQP expression. RESULTS Both membranes and placenta demonstrated expression of AQP1, -3, -8 and -9. Advancing gestation was associated with increased AF volume from e10 to e16, with a marked decrease in AF volume from e16 to e19. By immunohistochemistry, AQP1 was localized to placental vessels and AQP3 to trophoblast. AF volume was negatively correlated with fetal membrane AQP1 and placental AQP1 and AQP9 expression, and positively correlated with placental AQP3 expression. CONCLUSION Changes in AQPs with advancing gestation, and their correlation with AF volume, suggest a role in mediating placental and membrane water flow and ultimately AF volume. AQP1 appears to regulate fetal membrane water flow, and AQP3 is a likely candidate for the regulation of placental water flow.
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Sangalli MR, Mclean AJ, Peek MJ, Rivory LP, Le Couteur DG. Carbon monoxide disposition and permeability-surface area product in the foetal circulation of the perfused term human placenta. Placenta 2003; 24:8-11. [PMID: 12495653 DOI: 10.1053/plac.2002.0877] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In order to estimate the placental barrier to gas transfer, a novel carbon monoxide (CO) wash-in method was used to estimate the permeability-surface area (PS) product for the transfer of gas across the foetal circulation in the perfused human term placenta. The PS product for CO was 0.0096+/-0.006 ml/s/g or 0.012+/-0.007 ml/s/g using compartmental or Crone-Renkin analysis, respectively. Using this result and a published estimate of the placental capillary surface area, the permeability coefficient to CO across the foetal circulation was found to be approximately 4 x 10(-5)cm/s. This result is compatible with the hypothesis that the foetal circulation of the human placenta imposes a potentially significant barrier to gas transfer.
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Affiliation(s)
- M R Sangalli
- The Canberra Clinical School, University of Sydney, 2605 Australia.
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Powell TL, Jansson T, Illsley NP, Wennergren M, Korotkova M, Strandvik B. Composition and permeability of syncytiotrophoblast plasma membranes in pregnancies complicated by intrauterine growth restriction. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1420:86-94. [PMID: 10446293 DOI: 10.1016/s0005-2736(99)00096-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The objective of this study was to determine placental membrane permeabilities to water, urea and mannitol in intrauterine growth restriction (IUGR) and compare them to normal gestational age matched controls. Further, we wished to investigate whether potential changes in permeability were related to changes in membrane fluidity, cholesterol or phospholipid fatty acid content of the membranes. Syncytiotrophoblast microvillous (MVM) and basal membranes (BM) were isolated from normal and IUGR placentas at term. Passive permeability to water, urea, and mannitol showed no significant alterations in IUGR compared to controls. Cholesterol content in BM, but not in MVM, was lower in placentas from pregnancies complicated by IUGR. However, membrane fluidity did not change in these pregnancies. The phospholipid fatty acid composition of the plasma membranes isolated from all placentas showed a predominance of unsaturated fatty acid species in the BM and saturated species in the MVM. In the MVM from IUGR, mead acid (20:3), behenic acid (22:0) and nervonic acid (24:1) constituted higher percentages of the total when compared to normally grown controls. In the BM from IUGR, mead acid (20:3) was increased relative to the total phospholipid fatty acid content. In conclusion, the syncytiotrophoblast membranes exhibit only minor changes in passive permeability and composition when the pregnancy is complicated by IUGR.
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Affiliation(s)
- T L Powell
- Perinatal Center, Department of Physiology and Pharmacology, Göteborg University, Box 432, S-405 30, Göteborg, Sweden.
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