1
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Pique-Regi R, Romero R, Garcia-Flores V, Peyvandipour A, Tarca AL, Pusod E, Galaz J, Miller D, Bhatti G, Para R, Kanninen T, Hadaya O, Paredes C, Motomura K, Johnson JR, Jung E, Hsu CD, Berry SM, Gomez-Lopez N. A single-cell atlas of the myometrium in human parturition. JCI Insight 2022; 7:153921. [PMID: 35260533 PMCID: PMC8983148 DOI: 10.1172/jci.insight.153921] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 01/26/2022] [Indexed: 01/14/2023] Open
Abstract
Parturition is a well-orchestrated process characterized by increased uterine contractility, cervical ripening, and activation of the chorioamniotic membranes; yet, the transition from a quiescent to a contractile myometrium heralds the onset of labor. However, the cellular underpinnings of human parturition in the uterine tissues are still poorly understood. Herein, we performed a comprehensive study of the human myometrium during spontaneous term labor using single-cell RNA sequencing (scRNA-Seq). First, we established a single-cell atlas of the human myometrium and unraveled the cell type–specific transcriptomic activity modulated during labor. Major cell types included distinct subsets of smooth muscle cells, monocytes/macrophages, stromal cells, and endothelial cells, all of which communicated and participated in immune (e.g., inflammation) and nonimmune (e.g., contraction) processes associated with labor. Furthermore, integrating scRNA-Seq and microarray data with deconvolution of bulk gene expression highlighted the contribution of smooth muscle cells to labor-associated contractility and inflammatory processes. Last, myometrium-derived single-cell signatures can be quantified in the maternal whole-blood transcriptome throughout pregnancy and are enriched in women in labor, providing a potential means of noninvasively monitoring pregnancy and its complications. Together, our findings provide insights into the contributions of specific myometrial cell types to the biological processes that take place during term parturition.
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Affiliation(s)
- Roger Pique-Regi
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and.,Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Roberto Romero
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, USA.,Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan, USA.,Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, Michigan, USA.,Detroit Medical Center, Detroit, Michigan, USA
| | - Valeria Garcia-Flores
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Azam Peyvandipour
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and.,Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Adi L Tarca
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and.,Department of Computer Science, Wayne State University College of Engineering, Detroit, Michigan, USA
| | - Errile Pusod
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Jose Galaz
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Derek Miller
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Gaurav Bhatti
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Robert Para
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Tomi Kanninen
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Ola Hadaya
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Carmen Paredes
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Kenichiro Motomura
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | | | - Eunjung Jung
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Chaur-Dong Hsu
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and.,Department of Physiology and
| | - Stanley M Berry
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and
| | - Nardhy Gomez-Lopez
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, and Detroit, Michigan, USA.,Department of Obstetrics and Gynecology and.,Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
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2
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Human Myometrial Contractility Assays. Methods Mol Biol 2021. [PMID: 34550566 DOI: 10.1007/978-1-0716-1759-5_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Traditional contractility assays using an organ bath setup consist of several chambers (or baths) perfused with temperature-controlled, oxygenated physiological saline. Strips or rings of tissue (usually smooth or cardiac muscle) are mounted within the organ bath between a fixed hook and an isometric force transducer. The contraction force is recorded by the transducer and different parameters of contraction are analyzed. Different experimental protocols can be performed to investigate the effect of drugs and reagents on tissue contractility to investigate tissue physiology or determine the in vivo potential of novel pharmaceutical compounds. Here, the application of a modified organ bath to measure ex vivo contractions of small strips of human uterine smooth muscle (myometrium) is described, as well as protocols to study the effect of oxytocin and uterine relaxants on contraction.
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3
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Bafor EE, Prendergast C, Wray S. Justicia flava leaf extract potently relaxes pregnant human myometrial contractility: a lead plant for drug discovery of new tocolytic drugs. Exp Physiol 2020; 105:2033-2037. [PMID: 33094534 DOI: 10.1113/ep088819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/13/2020] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Can Justicia flava leaf extract (JF) inhibit human myometrial contractility as was previously shown in mouse myometrium? What is the main finding and its importance? JF abolished human myometrial contractions and therefore presents as a lead plant in drug discovery studies involving drugs for preterm birth. ABSTRACT In the search for new potent therapies for preterm labour, Justicia flava leaf extract (JF) was previously shown to potently inhibit uterine contractility in both pregnant and non-pregnant mouse uterus. This study took the investigation a step further and investigated the activity of JF on pregnant human myometrial contractility. JF potently inhibited human myometrial contractility in a concentration-dependent manner. This pilot study provides evidence that JF should be further investigated as a lead plant in the drug discovery of new uterine relaxants.
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Affiliation(s)
- Enitome E Bafor
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Benin, Benin City, Edo State, Nigeria
| | - Clodagh Prendergast
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Susan Wray
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
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4
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Human Uterine Biopsy: Research Value and Common Pitfalls. Int J Reprod Med 2020; 2020:9275360. [PMID: 32411783 PMCID: PMC7206876 DOI: 10.1155/2020/9275360] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/26/2020] [Accepted: 04/10/2020] [Indexed: 12/15/2022] Open
Abstract
The human uterus consists of the inner endometrium, the myometrium, and the outer serosa. Knowledge of the function of the uterus in health and disease is relevant to reproduction, fertility, embryology, gynaecology, endocrinology, and oncology. Research performed on uterine biopsies is essential to further the current understanding of human uterine biology. This brief review explores the value of the uterine biopsy in gynaecological and human fertility research and explores the common problems encountered when analysing data generated from different types of uterine biopsies, with the aim of improving the quality, reproducibility, and clinical translatability of future research.
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5
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Prendergast C, Wray S. Human myometrial artery function and endothelial cell calcium signalling are reduced by obesity: Can this contribute to poor labour outcomes? Acta Physiol (Oxf) 2019; 227:e13341. [PMID: 31299139 DOI: 10.1111/apha.13341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/17/2019] [Accepted: 07/07/2019] [Indexed: 12/15/2022]
Abstract
AIMS Determining how obesity affects function in human myometrial arteries, to help understand why childbirth has poor outcomes in obese women. METHODS Myometrial arteries were studied from 84 biopsies. Contraction (vasopressin and U-46619) and relaxation (carbachol, bradykinin, SNAP) was assessed using wire myography. eNOS activity was assessed using L-NAME. Cholesterol was reduced using methyl-β-cyclodextrin to determine whether it altered responses. Differences in endothelial cell intracellular Ca2+ signalling were assessed using confocal microscopy. RESULTS The effects of BMI on relaxation were agonist specific and very marked; all vessels, irrespective of BMI, relaxed to bradykinin but 0% of vessels (0/13) from obese women relaxed to carbachol, compared to 59% (10/17) from normal weight women. Cholesterol-lowering drugs did not restore carbachol responses (n = 6). All vessels, irrespective of BMI, relaxed when NO was directly released by SNAP (n = 19). Inhibition of eNOS with L-NAME had a significant effect in normal but not overweight/obese vessels. Compared to bradykinin, a lower proportion of endothelial cells responded to carbachol and the amplitude of the calcium response was significantly less, in all vessels. Furthermore, a significantly lower proportion of endothelial cells responded to carbachol in the overweight/obese group compared to control. In contrast to relaxation, the effect of contractile agonists was unchanged with increasing BMI. CONCLUSIONS The ability of human myometrial arteries to relax is significantly impaired with obesity, and our data suggest this is due to a deficit in endothelial calcium signalling. This inability to recover following compression during contractions, might contribute to poor labours in obese women.
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Affiliation(s)
- Clodagh Prendergast
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine University of Liverpool Liverpool UK
| | - Susan Wray
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine University of Liverpool Liverpool UK
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6
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Ryan GA, Crankshaw DJ, Morrison JJ. Effects of maternal parity on response of human myometrium to oxytocin and ergometrine in vitro. Eur J Obstet Gynecol Reprod Biol 2019; 242:99-102. [PMID: 31580965 DOI: 10.1016/j.ejogrb.2019.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/09/2019] [Accepted: 09/12/2019] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The aim of this study was to compare the effects of oxytocin and ergometrine on the intrinsic contractile parameters of human uterine smooth muscle at term between primiparous and multiparous women. STUDY DESIGN Myometrial biopsies were obtained from women undergoing planned caesarean section at term. The biopsies were dissected into eight uniform strips and mounted in tissue baths for isometric recording. The strips were challenged with increasing concentrations of oxytocin and ergometrine. Parameters of contractile activity, including mean contractile force (MCF) and maximum amplitude of contractions (MAMP) were recorded and analysed. Results were compared between primiparous (Group 1) and multiparous (Group 2) women. RESULTS Myometrial biopsies were obtained from n = 11 donors (88 tissue strips), of which n = 5 were Group 1 and n = 6 were Group 2. In relation to oxytocin, the MAMP value observed was significantly greater in Group 2 than in Group 1 (151 ± 18mN vs 67 ± 14mN, P < 0.01). Regarding ergometrine, the MCF response was greater in Group 2 samples (24 ± 10 mN) than that in Group 1 (18 ± 2mN) (P < 0.05). CONCLUSION Our findings highlight that women in a first pregnancy have a decreased response to both oxytocin and ergometrine in an in vitro setting when compared with women in a subsequent pregnancy, and this may have clinical implications regarding the management of postpartum haemorrhage in this cohort.
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Affiliation(s)
- Gillian A Ryan
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway University Hospital, Ireland; Lambe Institute for Translational Research, National University of Ireland, Galway, Ireland.
| | - Denis J Crankshaw
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway University Hospital, Ireland; Lambe Institute for Translational Research, National University of Ireland, Galway, Ireland
| | - John J Morrison
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway University Hospital, Ireland; Lambe Institute for Translational Research, National University of Ireland, Galway, Ireland
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7
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Arrowsmith S, Keov P, Muttenthaler M, Gruber CW. Contractility Measurements of Human Uterine Smooth Muscle to Aid Drug Development. J Vis Exp 2018. [PMID: 29443077 PMCID: PMC5841565 DOI: 10.3791/56639] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Discovery and characterization of novel pharmaceutical compounds or biochemical probes rely on robust and physiologically relevant assay systems. We describe methods to measure ex vivo myometrium contractility. This assay can be used to investigate factors and molecules involved in the modulation of myometrial contraction and to determine their excitatory or inhibitory actions, and hence their therapeutic potential in vivo. Biopsies are obtained from women undergoing cesarean section delivery with informed consent. Fine strips of myometrium are dissected, clipped and attached to a force transducer within 1 mL organ baths superfused with physiological saline solution at 37 °C. Strips develop spontaneous contractions within 2-3 h under set tension and remain stable for many hours (>6 h). Strips can also be stimulated to contract such as by the endogenous hormones, oxytocin and vasopressin, which cause concentration-dependent modulation of contraction frequency, force and duration, to more closely resemble contractions in labor. Hence, the effect of known and novel drug leads can be tested on spontaneous and agonist-induced contractions. This protocol specifically details how this assay can be used to determine the potency of known and novel agents by measuring their effects on various parameters of human myometrial contraction. We use the oxytocin- and V1a receptor antagonists, atosiban and SR49059 as examples of known compounds which inhibit oxytocin- and vasopressin-induced contractions, and demonstrate how this method can be used to complement and validate pharmacological data obtained from cell-based assays to aid drug development. The effects of novel agonists in comparison to oxytocin and vasopressin can also be characterized. Whilst we use the example of the oxytocin/ vasopressin system, this method can also be used to study other receptors and ion channels that play a role in uterine contraction and relaxation to advance the understanding of human uterine physiology and pathophysiology.
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Affiliation(s)
- Sarah Arrowsmith
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool;
| | - Peter Keov
- School of Biomedical Sciences, The University of Queensland
| | - Markus Muttenthaler
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna; Institute for Molecular Bioscience, University of Queensland
| | - Christian W Gruber
- School of Biomedical Sciences, The University of Queensland; Center for Physiology and Pharmacology, Medical University of Vienna;
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8
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Muttenthaler M, Andersson Å, Vetter I, Menon R, Busnelli M, Ragnarsson L, Bergmayr C, Arrowsmith S, Deuis JR, Chiu HS, Palpant NJ, O'Brien M, Smith TJ, Wray S, Neumann ID, Gruber CW, Lewis RJ, Alewood PF. Subtle modifications to oxytocin produce ligands that retain potency and improved selectivity across species. Sci Signal 2017; 10:10/508/eaan3398. [PMID: 29208680 DOI: 10.1126/scisignal.aan3398] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxytocin and vasopressin mediate various physiological functions that are important for osmoregulation, reproduction, cardiovascular function, social behavior, memory, and learning through four G protein-coupled receptors that are also implicated in high-profile disorders. Targeting these receptors is challenging because of the difficulty in obtaining ligands that retain selectivity across rodents and humans for translational studies. We identified a selective and more stable oxytocin receptor (OTR) agonist by subtly modifying the pharmacophore framework of human oxytocin and vasopressin. [Se-Se]-oxytocin-OH displayed similar potency to oxytocin but improved selectivity for OTR, an effect that was retained in mice. Centrally infused [Se-Se]-oxytocin-OH potently reversed social fear in mice, confirming that this action was mediated by OTR and not by V1a or V1b vasopressin receptors. In addition, [Se-Se]-oxytocin-OH produced a more regular contraction pattern than did oxytocin in a preclinical labor induction and augmentation model using myometrial strips from cesarean sections. [Se-Se]-oxytocin-OH had no activity in human cardiomyocytes, indicating a potentially improved safety profile and therapeutic window compared to those of clinically used oxytocin. In conclusion, [Se-Se]-oxytocin-OH is a novel probe for validating OTR as a therapeutic target in various biological systems and is a promising new lead for therapeutic development. Our medicinal chemistry approach may also be applicable to other peptidergic signaling systems with similar selectivity issues.
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Affiliation(s)
- Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia. .,Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Åsa Andersson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.,School of Pharmacy, The University of Queensland, Brisbane, Queensland 4104, Australia
| | - Rohit Menon
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, 93053 Regensburg, Germany
| | - Marta Busnelli
- CNR-Institute of Neuroscience, 20129 Milan, Italy.,Department of Biotechnology and Translational Medicine, University of Milan, 20129 Milan, Italy
| | - Lotten Ragnarsson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Christian Bergmayr
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Sarah Arrowsmith
- Department of Cellular and Molecular Physiology, Harris-Wellbeing Preterm Birth Centre, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Han Sheng Chiu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Nathan J Palpant
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Margaret O'Brien
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway H91 CF50, Ireland
| | - Terry J Smith
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway H91 CF50, Ireland
| | - Susan Wray
- Department of Cellular and Molecular Physiology, Harris-Wellbeing Preterm Birth Centre, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Inga D Neumann
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, 93053 Regensburg, Germany
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria.,School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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9
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Crankshaw DJ, O'Brien YM, Crosby DA, Morrison JJ. Maternal body mass index and spontaneous contractility of human myometrium in pregnancy. J Perinatol 2017; 37:492-497. [PMID: 28125101 DOI: 10.1038/jp.2016.271] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 11/28/2016] [Accepted: 12/01/2016] [Indexed: 11/09/2022]
Abstract
OBJECTIVE There is controversy as to whether maternal body mass index (BMI) influences the contractility of human myometrium in pregnancy. The aim of this study was to examine spontaneous contractile activity of human pregnant myometrium in vitro, with respect to maternal BMI. STUDY DESIGN Myometrial tissue specimens were obtained at cesarean delivery from 74 women with BMI values ranging from 19 to 50.1 kg m-2. By recording in vitro from eight strips per donor (590 strips in total), several parameters of spontaneous contractile activity were monitored. The relationship between BMI and contractility was evaluated using linear regression analysis. RESULTS There was a significant correlation between maximum amplitude (P=0.007) and mean contractile force (P=0.001) with increasing BMI. However, the time to onset of contractions (P=0.009), and time taken to reach maximal amplitude (P=0.020) also increased with increasing BMI. No significant correlation was observed with BMI for other parameters studied. The mean maximum amplitude value for spontaneous contractions was 37±1 mN, the mean contractile force for spontaneous contractions was 4.1±0.1 mN, the average time to the first spontaneous contraction was 11.3±0.6 min and the average frequency of contractions was 6.5±0.2 per hour. CONCLUSIONS These results suggest that the time to onset of contractions is increased with increasing maternal BMI, but that the force developed is greater. In all other respects, human uterine contractility is unaffected by increasing BMI. These findings underline the complexity of regulation of uterine contractility in labor with elevated maternal BMI.
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Affiliation(s)
- D J Crankshaw
- Department of Obstetrics and Gynecology, National University of Ireland Galway, Galway University Hospital, Galway, Ireland
| | - Y M O'Brien
- Department of Obstetrics and Gynecology, National University of Ireland Galway, Galway University Hospital, Galway, Ireland
| | - D A Crosby
- Department of Obstetrics and Gynecology, National University of Ireland Galway, Galway University Hospital, Galway, Ireland
| | - J J Morrison
- Department of Obstetrics and Gynecology, National University of Ireland Galway, Galway University Hospital, Galway, Ireland
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10
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Di Giglio MG, Muttenthaler M, Harpsøe K, Liutkeviciute Z, Keov P, Eder T, Rattei T, Arrowsmith S, Wray S, Marek A, Elbert T, Alewood PF, Gloriam DE, Gruber CW. Development of a human vasopressin V 1a-receptor antagonist from an evolutionary-related insect neuropeptide. Sci Rep 2017; 7:41002. [PMID: 28145450 PMCID: PMC5286520 DOI: 10.1038/srep41002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 12/13/2016] [Indexed: 01/27/2023] Open
Abstract
Characterisation of G protein-coupled receptors (GPCR) relies on the availability of a toolbox of ligands that selectively modulate different functional states of the receptors. To uncover such molecules, we explored a unique strategy for ligand discovery that takes advantage of the evolutionary conservation of the 600-million-year-old oxytocin/vasopressin signalling system. We isolated the insect oxytocin/vasopressin orthologue inotocin from the black garden ant (Lasius niger), identified and cloned its cognate receptor and determined its pharmacological properties on the insect and human oxytocin/vasopressin receptors. Subsequently, we identified a functional dichotomy: inotocin activated the insect inotocin and the human vasopressin V1b receptors, but inhibited the human V1aR. Replacement of Arg8 of inotocin by D-Arg8 led to a potent, stable and competitive V1aR-antagonist ([D-Arg8]-inotocin) with a 3,000-fold binding selectivity for the human V1aR over the other three subtypes, OTR, V1bR and V2R. The Arg8/D-Arg8 ligand-pair was further investigated to gain novel insights into the oxytocin/vasopressin peptide-receptor interaction, which led to the identification of key residues of the receptors that are important for ligand functionality and selectivity. These observations could play an important role for development of oxytocin/vasopressin receptor modulators that would enable clear distinction of the physiological and pathological responses of the individual receptor subtypes.
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Affiliation(s)
- Maria Giulia Di Giglio
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072 Brisbane, Australia
| | - Kasper Harpsøe
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
| | - Zita Liutkeviciute
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Peter Keov
- School of Biomedical Sciences, The University of Queensland, QLD 4072 Brisbane, Australia
| | - Thomas Eder
- IST Austria (Institute of Science and Technology), Am Campus 1, 3400 Klosterneuburg, Austria
- CUBE-Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Thomas Rattei
- CUBE-Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Sarah Arrowsmith
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, L69 3BX, United Kingdom
| | - Susan Wray
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, L69 3BX, United Kingdom
| | - Ales Marek
- Laboratory of Radioisotopes, Institute of Organic Chemistry and Biochemistry CAS, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
| | - Tomas Elbert
- Laboratory of Radioisotopes, Institute of Organic Chemistry and Biochemistry CAS, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
| | - Paul F. Alewood
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072 Brisbane, Australia
| | - David E. Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
| | - Christian W. Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
- School of Biomedical Sciences, The University of Queensland, QLD 4072 Brisbane, Australia
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11
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Arrowsmith S, Neilson J, Wray S. The combination tocolytic effect of magnesium sulfate and an oxytocin receptor antagonist in myometrium from singleton and twin pregnancies. Am J Obstet Gynecol 2016; 215:789.e1-789.e9. [PMID: 27555315 DOI: 10.1016/j.ajog.2016.08.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/01/2016] [Accepted: 08/09/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Preterm birth at <37 weeks of gestation is the most common and costly complication of pregnancy and remains the leading cause of neonatal morbidity, death, and reduced achievement in surviving infants. Magnesium sulfate is 1 class of tocolytics for threatened preterm labor; however, its clinical efficacy has been questioned. Twin pregnancies are at increased risk of preterm delivery compared with singleton gestations, which suggests that there is twin-specific risk to preterm delivery in twins. The prevention strategies that are applied to singleton pregnancies, however, have not been shown to be effective in twin pregnancies. OBJECTIVE The purpose of this study was to compare the relaxant effect of magnesium sulfate on spontaneous and oxytocin-augmented contractions of human myometrium from singleton and twin pregnancies and to examine whether the effect of oxytocin on magnesium sulfate's potency could be reversed with the use of the oxytocin receptor antagonist, atosiban. STUDY DESIGN Myometrium was obtained at the time of prelabor cesarean section (36-40 weeks of gestation) from women with singleton (n=23) or twin (n=12) pregnancy. Isometric tension recordings were made on myometrial strips that were mounted in organ baths that were superfused with physiologic saline solution. Strips were exposed to rising concentrations of magnesium sulfate, and the effect on spontaneous contractions or stimulated with oxytocin (0.5 nmol/L) and in the presence or absence of atosiban (100 nmol/L) was recorded. The contractile characteristics after each application of magnesium sulfate, which included amplitude of contraction and activity integral, were measured. Concentration-response curves were fitted with the use of nonlinear regression and comparison of the negative logarithm of the 50% reduction in activity values. RESULTS Magnesium sulfate exerted an equal concentration-dependent inhibitory effect on spontaneous myometrial contractions from both singleton and twin myometrium (P>.05). The application of oxytocin produced a significant rightward shift in the concentration-response curves (P<.0001), but no differences were found between pregnancy groups (P>.05). The addition of atosiban shifted concentration-response curves significantly back to the left for amplitude of contraction and activity integral in singletons (P<.0001). However, only activity integral was significantly reversed in twins (P<.01). CONCLUSION Magnesium sulfate is equipotent in suppressing contractions in singleton and twin myometrium. Oxytocin (0.5 nmol/L) significantly reduces the tocolytic potency of magnesium sulfate, which may explain, in part, magnesium sulfate's poor efficacy in vivo; however, this can be reversed partially by the use of an oxytocin receptor antagonist. Combination tocolysis that involves oxytocin receptor antagonists requires further investigation.
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Affiliation(s)
- Sarah Arrowsmith
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, the Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
| | - James Neilson
- Department of Women's and Children's Health, the Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Susan Wray
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, the Institute of Translational Medicine, University of Liverpool, Liverpool, UK
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12
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Ku CY, Babich L, Word RA, Zhong M, Ulloa A, Monga M, Sanborn BM. Expression of Transient Receptor Channel Proteins in Human Fundal Myometrium in Pregnancy. ACTA ACUST UNITED AC 2016; 13:217-25. [PMID: 16527499 DOI: 10.1016/j.jsgi.2005.12.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Cation channels comprised of transient receptor potential (TrpC) proteins may play a role in signal-regulated calcium entry and calcium homeostasis in myometrium. The objective of this study was to determine the relative abundance of specific TrpC mRNAs expressed in human myometrium and determine if TrpC mRNA and protein concentrations differ in fundal myometrium before and after the onset of labor. METHODS A quantitative real-time polymerase chain reaction (Q-RT-PCR) procedure was developed for determining the concentration of TrpC mRNA expression in immortalized and primary human myometrial cells and myometrial fundus tissues from patients before and after the onset of labor. The corresponding TrpC proteins were detected by Western blot analysis and immunohistochemistry. RESULTS hTrpC1, 3, 4, 5, 6, and 7 mRNAs were expressed in two lines of immortalized human myometrial cells and in primary human myocytes. In all of these cells, hTrpC1 and hTrpC4 mRNAs were the most abundant, followed by hTrpC6. A similar distribution was observed in fundal myometrium samples from patients before and after the onset of labor. hTrpC4 mRNA was significantly lower after the onset of labor; there were no significant changes in the concentrations of other TrpC mRNAs. Immunohistochemistry identified hTrpC1, 3, 4, and 6 proteins in myometrial smooth muscle cells. Western blot analysis of myometrial membranes demonstrated no statistically significant changes in hTrpC1, 3, 4, and 6 proteins between samples collected before and after the onset of labor. CONCLUSIONS We have demonstrated that hTrpC1 and hTrpC4 are the most abundant TrpC mRNAs in human myometrium, with TrpC6 being the next most abundant. There was no increase in TrpC mRNA or protein in fundal myometrium with the onset of labor. Nonetheless, these isoforms may play significant roles in signal regulated calcium entry in human myometrium.
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Affiliation(s)
- Chun-Ying Ku
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
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13
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Ku CY, Word RA, Sanborn BM. Differential Expression of Protein Kinase A, AKAP 79, and PP2B in Pregnant Human Myometrial Membranes Prior to and During Labor. ACTA ACUST UNITED AC 2016; 12:421-7. [PMID: 15914039 DOI: 10.1016/j.jsgi.2005.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We have previously shown that the association of protein kinase A (PKA) with purified myometrial plasma membrane declined at the end of pregnancy in the rat. This study was designed to determine if a similar decline in PKA occurred in pregnant human myometrium. METHODS Myometrial plasma membranes were isolated from lower uterine segment tissues from not-in-labor (NIL) and in-labor (IL) patients undergoing cesarean delivery. Membrane proteins were subjected to Western blot analysis to detect PKA-catalytic (PKA-cat) and PKA-regulatory (PKA-reg) subunits, the PKA binding protein A-kinase anchoring protein 79 (AKAP79), protein phosphatase 2B (PP2B), and Galphaq, a guanosine triphosphate (GTP)-binding protein. Protein levels were expressed relative to caveolin-1, which was invariant between the two groups. RESULTS The amount of PKA-cat, PKA-reg, AKAP79, and PP2B in plasma membranes from myometrium of women in early labor decreased significantly compared with that in tissues from women not in labor. In contrast, Galphaq did not change. All proteins were localized to myometrial smooth muscle cells by immunohistochemistry. CONCLUSIONS Expression of PKA, PP2B, and AKAP79 is consistent with the presence of a functional AKAP-mediated signaling complex in pregnant human myometrial membranes. A small but significant decrease in PKA, AKAP79, and PP2B in myometrial tissues from women in labor may contribute to a decrease in negative feedback on and enhancement of contractant signals at term.
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Affiliation(s)
- Chun-Ying Ku
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
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14
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Differing In Vitro Potencies of Tocolytics and Progesterone in Myometrium From Singleton and Twin Pregnancies. Reprod Sci 2015; 23:98-111. [DOI: 10.1177/1933719115597788] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Xu C, Liu W, You X, Leimert K, Popowycz K, Fang X, Wood SL, Slater DM, Sun Q, Gu H, Olson DM, Ni X. PGF2α modulates the output of chemokines and pro-inflammatory cytokines in myometrial cells from term pregnant women through divergent signaling pathways. Mol Hum Reprod 2015; 21:603-14. [PMID: 25882540 DOI: 10.1093/molehr/gav018] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 04/08/2015] [Indexed: 02/07/2023] Open
Abstract
Prostaglandin F2α (PGF2α) plays a critical role in the initiation and process of parturition. Since human labor has been described as an inflammatory event, we investigated the role of PGF2α in the inflammatory process using cultured human uterine smooth muscle cells (HUSMCs) isolated from term pregnant women as a model. Using a multiplex assay, HUSMCs treated with PGF2α changed their output of a number of cytokines and chemokines, with a distinct response pattern that differed between HUSMCs isolated from the upper and lower segment region of the uterus. Confirmatory enzyme-linked immunosorbent assays (ELISAs) showed that PGF2α stimulated increased output of interleukin (IL) 1β, IL6, IL8 (CXCL8) and monocyte chemotactic protein-1 (MCP1, also known as chemokine (c-c motif) ligand 2, CCL2) by HUSMCs isolated from both upper and lower uterine segments. In contrast, PGF2α inhibited tumor necrosis factor α (TNFα) release by HUMSCs from the lower uterine segment while the output of TNFα was undetectable in the upper segment. Small interfering (si) RNA mediated knockdown of the PGF2α receptor prevented the changes in cytokine and chemokine output by the HUSMCs. Since the PGF2α receptor (PTGFR) couples via the Gq protein and subsequently activates the phospholipase C (PLC) and protein kinase C (PKC) signaling pathways, we examined the role of these pathways in PGF2α modulation of the cytokines. Inhibition of PLC and PKC reversed the effects of PGF2α. PGF2α activated multiple signaling pathways including extracellular signal-regulated kinases (ERK) 1/2, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), P38, calcineurin/nuclear factor of activated T-cells (NFAT) and NF-κB signaling. Inhibition of ERK reversed PGF2α-induced IL1β, IL6 and CCL2 output, while inhibition of PI3K blocked the effect of PGF2α on IL6, CXCL8 and CCL2 output and inhibition of NF-κB reversed PGF2α-induced IL1β and CCL2 output. NFAT was involved in PGF2α modulation of CCL2 and TNFα output. In conclusion, our results support a role of PGF2α in creating an inflammatory environment during the late stage of human pregnancy.
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Affiliation(s)
- Chen Xu
- Department of Physiology, Second Military Medical University, Shanghai 200433, China Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada
| | - Weina Liu
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
| | - Xingji You
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
| | - Kelycia Leimert
- Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada
| | - Krystyn Popowycz
- Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada
| | - Xin Fang
- Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada
| | - Stephen L Wood
- Department of Obstetrics and Gynecology, University of Calgary, Calgary T2N1N4, Canada
| | - Donna M Slater
- Department of Obstetrics and Gynecology, University of Calgary, Calgary T2N1N4, Canada Departments of Physiology and Pharmacology, University of Calgary, Calgary T2N1N4, Canada
| | - Qianqian Sun
- Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - Hang Gu
- Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - David M Olson
- Departments of Physiology, Obstetrics & Gynecology, and Pediatrics, University of Alberta, Edmonton T6G2S2, Canada
| | - Xin Ni
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
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16
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Crankshaw DJ, O'Brien YM, Crosby DA, Morrison JJ. Maternal Age and Contractility of Human Myometrium in Pregnancy. Reprod Sci 2015; 22:1229-35. [PMID: 25759369 DOI: 10.1177/1933719115572483] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
There is controversy as to whether maternal age exerts an influence on the contractility of human myometrium in pregnancy. The aim of this study was to examine a series of functional contractile parameters of human myometrium in vitro, over a broad range of maternal ages. Myometrial tissue specimens were obtained at cesarean delivery from 32 women with maternal ages ranging from 28 to 52 years. Using in vitro recordings, a number of contractile parameters including maximal amplitude, mean contractile force, time to maximal amplitude, maximum rate of rise, and occurrence of simple and complex (biphasic and multiphasic) contractions were examined for spontaneous and induced contractile activity. The relationship between maternal age and individual parameters was evaluated using linear regression analysis. For all contractile parameters examined, for both spontaneous and induced contractions, no significant correlation was observed with maternal age between 28 and 52 years. The mean maximum amplitude values for spontaneous and oxytocin-induced contractions were 23 ± 3 and 43 ± 5 mN, respectively. The mean contractile forces for spontaneous and oxytocin-induced contractions were 1.5 ± 0.2 and 6.5 ± 0.9 mN, respectively. There was no variation in the proportion of biphasic or multiphasic contractions with maternal age. These results indicate there is no significant functional impairment of uterine contractility and no lack in responsiveness of myometrium in vitro, in the older mother. These findings do not support the concept that there may be a biological basis for dysfunctional labor or increased cesarean delivery rates in older parturients.
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Affiliation(s)
- Denis J Crankshaw
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland
| | - Yvonne M O'Brien
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland
| | - David A Crosby
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland
| | - John J Morrison
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland
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17
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Mumtaz S, AlSaif S, Wray S, Noble K. Inhibitory effect of visfatin and leptin on human and rat myometrial contractility. Life Sci 2015; 125:57-62. [DOI: 10.1016/j.lfs.2015.01.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 01/20/2015] [Accepted: 01/23/2015] [Indexed: 12/01/2022]
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18
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Wray S, Burdyga T, Noble D, Noble K, Borysova L, Arrowsmith S. Progress in understanding electro-mechanical signalling in the myometrium. Acta Physiol (Oxf) 2015; 213:417-31. [PMID: 25439280 DOI: 10.1111/apha.12431] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 11/11/2014] [Accepted: 11/17/2014] [Indexed: 11/30/2022]
Abstract
In this review, we give a state-of-the-art account of uterine contractility, focussing on excitation-contraction (electro-mechanical) coupling (ECC). This will show how electrophysiological data and intracellular calcium measurements can be related to more modern techniques such as confocal microscopy and molecular biology, to advance our understanding of mechanical output and its modulation in the smooth muscle of the uterus, the myometrium. This new knowledge and understanding, for example concerning the role of the sarcoplasmic reticulum (SR), or stretch-activated K channels, when linked to biochemical and molecular pathways, provides a clearer and better informed basis for the development of new drugs and targets. These are urgently needed to combat dysfunctions in excitation-contraction coupling that are clinically challenging, such as preterm labour, slow to progress labours and post-partum haemorrhage. It remains the case that scientific progress still needs to be made in areas such as pacemaking and understanding interactions between the uterine environment and ion channel activity.
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Affiliation(s)
- S. Wray
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - T. Burdyga
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - D. Noble
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - K. Noble
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - L. Borysova
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - S. Arrowsmith
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
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19
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Sweeney EM, Dockery P, Crankshaw DJ, O'Brien YM, Walsh JM, Morrison JJ. Human uterine lower segment myometrial cell and nuclear volume at term: influence of maternal age. J Anat 2014; 225:625-33. [PMID: 25265023 DOI: 10.1111/joa.12240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2014] [Indexed: 10/24/2022] Open
Abstract
Little is known about the cytoarchitecture of human myometrial cells in pregnancy, and whether or not this may be influenced by maternal characteristics such as age, parity and body mass index (BMI). The aim of this study was primarily to evaluate human myometrial smooth muscle cell (SMC) and nuclear volume in the third trimester of human pregnancy, and secondarily to investigate if these parameters are altered in relation to the maternal characteristics outlined above. Myometrial biopsies were obtained from 30 women undergoing elective caesarean delivery at term. One-micrometer sections were prepared for light microscopy and 100-nm sections for electron microscopy. The nucleator technique was used to assess nuclear volume from the light microscopy images. Point-counting methodology was used on transmission electron micrographs to assess the percentage of the cell volume occupied by the nucleus. Cell volume was calculated from these measurements. The euchromatin to heterochromatin (Eu/Het) ratio was determined to ascertain whether differences in nuclear volume were due to an increased range of genes being transcribed. The mean (± SEM) nuclear volume was 175 ± 10 μm(3) , the nucleus occupied 1.5 ± 0.1% of the SMC and the mean cell size was 14 047 ± 1352 μm(3) . The Eu/Het ratio was 7.54 ± 0.4. The mean volume of heterochromatin and euchromatin in the nucleus was 21.5 ± 1.7 and 149 ± 9 μm(3) , respectively. A multivariate regression analysis revealed that advanced maternal age was associated with an increase in the percentage of the cell occupied by nucleus (R(2) = 0.32, P = 0.004). There were no other significant effects of maternal age, BMI or parity on the measured parameters. These findings provide reliable volumes for human myometrial cells and their nuclei at term gestation, and show that nuclear volume fraction may be influenced by maternal age.
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Affiliation(s)
- Eva M Sweeney
- Department of Obstetrics and Gynaecology, National University of Ireland, Galway, Ireland; Anatomy, School of Medicine, National University of Ireland, Galway, Ireland
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20
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Crankshaw DJ, Sweeney EM, O'Brien YM, Walsh JM, Dockery P, Morrison JJ. The influence of smooth muscle content and orientation in dissected human pregnant myometrial strips on contractility measurements. Eur J Pharmacol 2014; 738:245-9. [PMID: 24886879 DOI: 10.1016/j.ejphar.2014.05.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 05/20/2014] [Accepted: 05/21/2014] [Indexed: 11/19/2022]
Abstract
This study examined the hypothesis that the force generated by myometrial strips from pregnant women is influenced by the smooth muscle content and fibre orientation of the strips and that correcting for these structural variables will provide a more accurate measure of contractility. Myometrial strips (n=72) were contracted by exposure to KCl, oxytocin, U44619 and phenylephrine and maximum responses were recorded. Morphological techniques were used to determine the cross-sectional area of the strips, the area occupied by smooth muscle and the area occupied by smooth muscle longitudinal in the strip. Maximum responses to contractile agents were expressed in terms of these three variables. The mean cross sectional area of strips was 2.01 ± 0.06 mm(2), of which 50% was smooth muscle, and 18% was smooth muscle longitudinal in the strip (n=72). There was much heterogeneity in responses, smooth muscle content and fibre orientation. Correction for morphological variability did not improve the heterogeneity in responses where coefficients of variation among strips from the same donor ranged from 43% to 63% when expressed in relation to longitudinal smooth muscle cross-sectional area. The standard method of preparation of myometrial strips for in vitro recording results in samples that are not structurally uniform. Correcting for the known structural variables does not provide a more accurate measure of maximum contractile responses. Because of the heterogeneity shown here, experiments that are dependent upon accurate estimation of maximum contractile responses require a large number of replicates to reach meaningful conclusions.
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Affiliation(s)
- Denis J Crankshaw
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland
| | - Eva M Sweeney
- Department of Anatomy, National University of Ireland Galway, Galway, Ireland
| | - Yvonne M O'Brien
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland
| | - Jennifer M Walsh
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland
| | - Peter Dockery
- Department of Anatomy, National University of Ireland Galway, Galway, Ireland
| | - John J Morrison
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Galway, Ireland.
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21
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Turton P, Arrowsmith S, Prescott J, Ballard C, Bricker L, Neilson J, Wray S. A comparison of the contractile properties of myometrium from singleton and twin pregnancies. PLoS One 2013; 8:e63800. [PMID: 23671701 PMCID: PMC3646038 DOI: 10.1371/journal.pone.0063800] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/05/2013] [Indexed: 12/02/2022] Open
Abstract
Objective Over half of twin pregnancies in US and UK deliver prematurely but the reasons for this are unclear. The contractility of myometrium from twin pregnancies has not been directly investigated. The objective of this research was to determine if there are differences in the contractile activity and response to oxytocin, between myometrium from singleton and twin pregnancies, across a range of gestational ages. Furthermore, we wished to determine if contractile activity correlates with increasing level of stretch, using neonatal birth weights as a marker of uterine stretch. Methods This was an in vitro, laboratory based study of myometrial contractility in women pregnant with one or two babies, using biopsies obtained from non-labouring women undergoing Caesarean section. Spontaneous, oxytocin-stimulated and depolarization induced contractile activity was compared. Results Direct measurements of myometrial contractility under controlled conditions show that the frequency of contractions and responses to oxytocin are significantly increased in twins compared to singletons. The duration of contraction however was significantly reduced. We find that contractile activity correlates with increasing levels of stretch, using neonatal birth weights as a surrogate for uterine stretch, with response to oxytocin being significantly positively correlated with birth weight. Conclusions We have found significant differences in contractile properties between myometrium from singleton and twin pregnancies and that increasing uterine stretch can alter the contractile properties of myometrium. We discuss the implication of these findings to preterm delivery and future studies.
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Affiliation(s)
- Peter Turton
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Sarah Arrowsmith
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Jonathan Prescott
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Celia Ballard
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Leanne Bricker
- Liverpool Women's NHS Foundation Trust, Liverpool, United Kingdom
| | - James Neilson
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, United Kingdom
| | - Susan Wray
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
- * E-mail:
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Robinson H, Wray S. A new slow releasing, H₂S generating compound, GYY4137 relaxes spontaneous and oxytocin-stimulated contractions of human and rat pregnant myometrium. PLoS One 2012; 7:e46278. [PMID: 23029460 PMCID: PMC3459845 DOI: 10.1371/journal.pone.0046278] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 08/29/2012] [Indexed: 12/16/2022] Open
Abstract
Better tocolytics are required to help prevent preterm labour. The gaseotransmitter Hydrogen sulphide (H2S) has been shown to reduce myometrial contractility and thus is of potential interest. However previous studies used NaHS, which is toxic and releases H2S as a non-physiological bolus and thus alternative H2S donors are sought. GYY4137 has been developed to slowly release H2S and hence better reflect endogenous physiological release. We have examined its effects on spontaneous and oxytocin-stimulated contractility and compared them to NaHS, in human and rat myometrium, throughout gestation. The effects on contractility in response to GYY4137 (1 nM–1 mM) and NaHS (1 mM) were examined on myometrial strips from, biopsies of women undergoing elective caesarean section or hysterectomy, and from non-pregnant, 14, 18, 22 day (term) gestation or labouring rats. In pregnant rat and human myometrium dose-dependent and significant decreases in spontaneous contractions were seen with increasing concentrations of GYY4137, which also reduced underlying Ca transients. GYY4137 and NaHS significantly reduced oxytocin-stimulated and high-K depolarised contractions as well as spontaneous activity. Their inhibitory effects increased as gestation advanced, but were abruptly reversed in labour. Glibenclamide, an inhibitor of ATP-sensitive potassium (KATP) channels, abolished the inhibitory effect of GYY4137. These data suggest (i) H2S contributes to uterine quiescence from mid-gestation until labor, (ii) that H2S affects L-type calcium channels and KATP channels reducing Ca entry and thereby myometrial contractions, (iii) add to the evidence that H2S plays a physiological role in relaxing myometrium, and thus (iv) H2S is an attractive target for therapeutic manipulation of human myometrial contractility.
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Affiliation(s)
- Hayley Robinson
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Susan Wray
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
- * E-mail:
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Arrowsmith S, Robinson H, Noble K, Wray S. What do we know about what happens to myometrial function as women age? J Muscle Res Cell Motil 2012; 33:209-17. [PMID: 22644420 PMCID: PMC3413813 DOI: 10.1007/s10974-012-9300-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 05/11/2012] [Indexed: 12/12/2022]
Abstract
Much has been written about the effects of aging on reproductive function, especially female fertility. Much less is known about how aging may affect the contractility of the smooth muscle within the uterus, the myometrium. The myometrium is active through a woman’s entire life, not just during pregnancy. Here we will discuss briefly the contractile functions of the uterus and the changes it undergoes throughout the stages of a woman’s life from menstruation and the menopause, before evaluating the evidence for any changes in myometrial contractility and responses as women age, with a particular focus on women of advanced maternal age. We present original contractility analysis for the widest data set for human myometrium so far examined, and determine inherent spontaneous activity as well as responses to depolarisation and stimulation with oxytocin. Our data show that in the non-pregnant state there is a significant decrease in contractility for both spontaneous and depolarised-induced contractions, with age. We suggest that muscle atrophy and down regulation of Ca channels may account for this. Interestingly in pregnant myometrium we found a wide range of contractile ability between women and little evidence for decreased spontaneous activity between the ages of 25–40. Oxytocin responses appear to be more affected by aging, a finding that is consistent with previously reported clinical findings, and may partly be the result of membrane lipids such as cholesterol, increasing as women age. The marked differences between the age-related decline of force beyond age 30 in non-pregnant uterus, and the lack of difference in the pregnant state over this period, shows that the uterus retains its ability to respond to gestational hormones. The growth of the pregnant uterus and increase in content of myofibrillar proteins, may abolish any previous age-related force deficit. This finding is consistent with what is apparent for postmenopausal women in their 50s and 60s; that with the appropriate hormonal stimulation the uterus can allow an embryo to implant, and then without further intervention, carry the foetus to term. It is tempting therefore to speculate that unlike other well documented declines in female reproductive functions with age, the myometrium remains able to function into a woman’s 7th decade.
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Affiliation(s)
- Sarah Arrowsmith
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
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Al-Qahtani S, Heath A, Quenby S, Dawood F, Floyd R, Burdyga T, Wray S. Diabetes is associated with impairment of uterine contractility and high Caesarean section rate. Diabetologia 2012; 55:489-98. [PMID: 22101974 PMCID: PMC3245824 DOI: 10.1007/s00125-011-2371-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 10/13/2011] [Indexed: 01/23/2023]
Abstract
AIMS/HYPOTHESIS The prevalence of births worldwide complicated by diabetes mellitus is increasing. In the UK, for example, <25% of diabetic women have a non-instrumental vaginal delivery. Strikingly, more than half the Caesarean sections (CS) in these patients are non-elective, but the reasons for this are not understood. We have tested the hypothesis that poor myometrial contractility as a consequence of the disease contributes to this high CS rate. METHODS We compared spontaneous, high K depolarisation and oxytocin-induced contractions from diabetic and matched control patients having an elective CS. To investigate the mechanism of any differences we measured intracellular Ca, and performed western blotting and compared the tissues histologically. RESULTS There was significantly decreased contraction amplitude and duration in uteri from diabetic compared with control patients, even when possible confounders such as BMI were analysed. Reduced intracellular calcium signals and expression of calcium entry channels were found in uteruses from diabetic patients, which, along with a reduction in muscle content found on histological examination, could explain the reduced force. Myometrium from diabetic patients was responsive to oxytocin, but still did not reach the levels found in non-diabetic patients. CONCLUSIONS/INTERPRETATIONS These are the first data investigating myometrium in diabetic patients and they support the hypothesis that there is poorer contractility even in the presence of oxytocin. The underlying mechanism is related to reduced Ca channel expression and intracellular calcium signals and a decrease in muscle mass. We conclude that these factors significantly contribute to the increased emergency CS rate in diabetic patients.
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Affiliation(s)
- S. Al-Qahtani
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX UK
- Department of Physiology, Medical College, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - A. Heath
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX UK
| | - S. Quenby
- Liverpool Women’s Hospital, University of Liverpool, Liverpool, UK
- Present Address: Clinical Sciences Research Institute, University of Warwick, Coventry, UK
| | - F. Dawood
- Liverpool Women’s Hospital, University of Liverpool, Liverpool, UK
| | - R. Floyd
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX UK
| | - T. Burdyga
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX UK
| | - S. Wray
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX UK
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Quenby S, Matthew A, Zhang J, Dawood F, Wray S. In vitro myometrial contractility reflects indication for caesarean section. BJOG 2011; 118:1499-506. [PMID: 21790954 DOI: 10.1111/j.1471-0528.2011.03064.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess the extent to which in vitro measurements of myometrial contractility reflect the clinical indication for caesarean section. DESIGN A prospective, observational hypothesis-generating study. SETTING Women were recruited from Liverpool Women's NHS Foundation Trust and experiments were performed in the Physiology Department at the University of Liverpool. POPULATION Myometrial samples were taken from women undergoing a caesarean section during labour (n = 50) or from women having a repeat nonlabouring caesarean section (n = 70). METHODS The demographic characteristics of the women and indications for current and previous caesarean sections were recorded. The force, frequency and duration of spontaneous contractions of myometrial strips, and changes in the intracellular calcium concentration of the strips, were measured. Kruskall-Wallis and post hoc tests were used to assess the significance of differences between groups. RESULTS Samples from women whose caesarean section was for fetal distress/acidosis (scalp pH <7.2) contracted with more force than those from women whose caesarean section was for delay in the first stage of labour (P < 0.001). For repeat, nonlabouring caesarean sections, samples from women whose first caesarean section was for fetal distress/acidosis also contracted with more force than did samples from women whose first caesarean section was for delay in the first stage of labour (P = 0.03). CONCLUSIONS These findings suggest that the myometrium contracts with greater force in women who have a caesarean section for fetal distress.
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Affiliation(s)
- S Quenby
- Clinical Sciences Research Institute, University of Warwick, Coventry, UK.
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Xu C, You X, Gao L, Zhang L, Hu R, Hui N, Olson DM, Ni X. Expression of ATP-sensitive potassium channels in human pregnant myometrium. Reprod Biol Endocrinol 2011; 9:35. [PMID: 21418633 PMCID: PMC3071315 DOI: 10.1186/1477-7827-9-35] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 03/21/2011] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Potassium channels play critical roles in the regulation of cell membrane potential, which is central to the excitability of myometrium. The ATP-sensitive potassium (KATP) channel is one of the most abundant potassium channels in myometrium. The objectives of this study were to investigate the protein expression of KATP channel in human myometrium and determine the levels of KATP channel in lower and upper segmental myometrium before and after onset of labour. METHODS Both lower segmental (LS) and upper segmental (US) myometrial biopsies were collected at cesarean section from pregnant women not-in-labour (TNL) or in-labour (TL) at term. Protein expression level and cellular localization of four KATP channel subunits in US and LS myometrium were determined by Western blot analysis and immunohistochemistry, respectively. The contractile activity of myometrial strip was measured under isometric conditions. RESULTS Four KATP channel subunits, namely Kir6.1, Kir6.2, SUR1 and SUR2B were identified in pregnant myometrium. While found in vascular myocytes, these subunits appear to be preferentially expressed in myometrial myocytes. Diazoxide, a KATP channel opener, inhibited the spontaneous contractility of pregnant myometrium, suggesting that the KATP channels are functional in human pregnant myometrium. Diazoxide was less potent in TL strips than that in TNL strips. Interestingly, expression of SUR1 was greater in TL than TNL tissues, although no differences were found for SUR2B in these two tissues. For both lower and upper segmental myometrium, Kir6.1 and Kir6.2 were less in TL compared with TNL tissues. CONCLUSIONS Functional KATP channels are expressed in human pregnant myometrium. Down-regulation of Kir6.1 and Kir6.2 expression in myometrium may contribute to the enhanced uterine contractility associated with the onset of labour.
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Affiliation(s)
- Chen Xu
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
| | - Xingji You
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
| | - Lu Gao
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
| | - Lanmei Zhang
- Department of Gynecology and Obstetric, Navy General Hospital, Beijing 10037, China
| | - Rong Hu
- Department of Gynecology and Obstetric, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - Ning Hui
- Department of Gynecology and Obstetric, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - David M Olson
- Departments of Obstetrics and Gynecology, Pediatrics and Physiology, University of Alberta, Edmonton T6G 2 S, Canada
| | - Xin Ni
- Department of Physiology, Second Military Medical University, Shanghai 200433, China
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Houlihan DD, Dennedy MC, Morrison JJ. Effects of abnormal cannabidiol on oxytocin-induced myometrial contractility. Reproduction 2010; 139:783-8. [PMID: 20068032 DOI: 10.1530/rep-09-0496] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The objective of this study was to investigate the effects of abnormal cannabidiol (abn-cbd) on oxytocin-induced myometrial contractility occurring during pregnancy. Isometric tension recordings were performed in isolated myometrial strips from biopsies obtained at elective cesarean section. The effects of cumulative doses of abn-cbd (10(-9)-10(-5) M) on oxytocin-induced myometrial contractions alone, and on those following pre-incubation with SR 144528, AM 251, methylene blue, and iberiotoxin were measured, and dose-response curves were constructed. The pD(2) (-log EC(50)) values and the maximal inhibitory (MMI) values that were achieved were compared for each tissue type. Abn-cbd exerted a potent relaxant effect on oxytocin-induced myometrial contractions in vitro. Pre-incubation with the guanylate cyclase inhibitor, methylene blue, and the BK(Ca) channel antagonist, iberiotoxin, significantly attenuated this effect (for pD(2), P<0.01; for MMI, P<0.01). Abn-cbd exerts a potent inhibitory effect on human uterine contractility. This effect is partially mediated through modulation of guanylate cyclase and activation of BK(Ca) channel activity. These findings have implications for physiologic regulation of myometrial quiescence.
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Affiliation(s)
- Diarmaid D Houlihan
- Department of Obstetrics and Gynecology, Clinical Sciences Institute, University College Hospital, National University of Ireland Galway, Newcastle Road, Galway, Ireland
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Higgins CA, Martin W, Anderson L, Blanks AM, Norman JE, McConnachie A, Nelson SM. Maternal obesity and its relationship with spontaneous and oxytocin-induced contractility of human myometrium in vitro. Reprod Sci 2009; 17:177-85. [PMID: 19828431 DOI: 10.1177/1933719109349780] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Maternal obesity is associated with increased rates of labor induction, dysfunctional labor requiring intrapartum cesarean delivery, and postpartum hemorrhage, implying that maternal obesity has an inhibitory effect on myometrial function and its ability to respond to oxytocin. This study aimed to use an in vitro model to investigate the relationship between maternal body mass index (BMI) and the ability of myometrium to contract spontaneously and in response to oxytocin. Linear mixed effects regression modeling was applied to contractile data from 609 strips from 85 women. No correlation was found between maternal BMI and any indices of spontaneous myometrial activity. A single addition of oxytocin increased contractility, however, this was not related to maternal BMI. Similarly, oxytocin concentration-response curves were unrelated to BMI. Overall, the results from this in vitro study suggest that the observed implications of obesity on parturition in vivo cannot be explained by a direct effect on myometrial contractile mechanisms per se.
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Affiliation(s)
- Claire A Higgins
- Reproductive & Maternal Medicine, Faculty of Medicine, University of Glasgow, United Kingdom.
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Anderson L, Martin W, Higgins C, Nelson SM, Norman JE. The Effect of Progesterone on Myometrial Contractility, Potassium Channels, and Tocolytic Efficacy. Reprod Sci 2009; 16:1052-61. [DOI: 10.1177/1933719109340926] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Laurie Anderson
- Reproductive and Maternal Medicine, Institute of Biomedical and Life Sciences University of Glasgow, Scotland, UK,
| | - William Martin
- Integrative and Systems Biology, Institute of Biomedical and Life Sciences University of Glasgow, Scotland, UK
| | - Claire Higgins
- Reproductive and Maternal Medicine, Institute of Biomedical and Life Sciences University of Glasgow, Scotland, UK
| | - Scott M. Nelson
- Reproductive and Maternal Medicine, Institute of Biomedical and Life Sciences University of Glasgow, Scotland, UK
| | - Jane E. Norman
- Centre for Reproductive Biology, University of Edinburgh, Scotland, UK
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Mitchell BF, Taggart MJ. Are animal models relevant to key aspects of human parturition? Am J Physiol Regul Integr Comp Physiol 2009; 297:R525-45. [PMID: 19515978 DOI: 10.1152/ajpregu.00153.2009] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Preterm birth remains the most serious complication of pregnancy and is associated with increased rates of infant death or permanent neurodevelopmental disability. Our understanding of the regulation of parturition remains inadequate. The scientific literature, largely derived from rodent animal models, suggests two major mechanisms regulating the timing of parturition: the withdrawal of the steroid hormone progesterone and a proinflammatory response by the immune system. However, available evidence strongly suggests that parturition in the human has significantly different regulators and mediators from those in most of the animal models. Our objectives are to critically review the data and concepts that have arisen from use of animal models for parturition and to rationalize the use of a new model. Many animal models have contributed to advances in our understanding of the regulation of parturition. However, we suggest that those animals dependent on progesterone withdrawal to initiate parturition clearly have a limitation to their translation to the human. In such models, a linear sequence of events (e.g., luteolysis, progesterone withdrawal, uterine activation, parturition) gives rise to the concept of a "trigger" mechanism. Conversely, we propose that human parturition may arise from the concomitant maturation of several systems in parallel. We have termed this novel concept "modular accumulation of physiological systems" (MAPS). We also emphasize the urgency to determine the precise role of the immune system in the process of parturition in situations other than intrauterine infection. Finally, we accentuate the need to develop a nonprimate animal model whose physiology is more relevant to human parturition. We suggest that the guinea pig displays several key physiological characteristics of gestation that more closely resemble human pregnancy than do currently favored animal models. We conclude that the application of novel concepts and new models are required to advance translational research in parturition.
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Affiliation(s)
- Bryan F Mitchell
- Department of Obstetrics & Gynecology, Heritage Medical Research Centre, University of Alberta, Edmonton, Alberta, Canada.
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Kendrick A, Quenby S, Wray S. Contractility and calcium signaling of human myometrium are profoundly affected by cholesterol manipulation: implications for labor? Reprod Sci 2007; 14:456-66. [PMID: 17913965 DOI: 10.1177/1933719107306229] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The authors elucidate cholesterol's effect on human uterine contractility and calcium signaling to test the hypotheses that elevation of cholesterol decreases uterine activity and that oxytocin cannot augment contraction when cholesterol is elevated. The effects of cholesterol extraction with methyl beta-cyclodextrin and enrichment with low-density lipoproteins and cholesterol on contractile activity and intracellular calcium signaling in spontaneous or oxytocin-stimulated myometrium are determined. Force occurring spontaneously and with oxytocin is significantly increased by cholesterol extraction. Cholesterol enrichment profoundly inhibits force production in a dose-dependent manner and could reverse the effects of cholesterol extraction. Qualitatively similar results are found for nonpregnant and pregnant laboring and non-laboring myometrium. These contractile changes are related to changes in intracellular Ca2+ . Thus, elevated cholesterol is deleterious to contractility and Ca2+ signaling in human myometrium. Cholesterol may contribute to uterine quiescence but could cause difficulties in labor in obese/dyslipidemic women, consistent with their increased cesarean delivery rates.
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Grigsby PL, Sooranna SR, Adu-Amankwa B, Pitzer B, Brockman DE, Johnson MR, Myatt L. Regional Expression of Prostaglandin E2 and F2alpha Receptors in Human Myometrium, Amnion, and Choriodecidua with Advancing Gestation and Labor1. Biol Reprod 2006; 75:297-305. [PMID: 16707767 DOI: 10.1095/biolreprod.106.051987] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The change from uterine quiescence to enhanced contractile activity may be due to the differential expression of prostaglandin receptors within the myometrium and fetal membranes, in a temporal and topographically distinct manner. To address this question, we determined the localization and expression of the PGE2 receptor subtypes (PTGER1-4) and the PGF2alpha receptor (PTGFR) in paired upper and lower segment myometrium, amnion, and choriodecidual samples throughout human pregnancy, with and without labor. All receptor subtypes were found throughout the muscle layers in both the upper and lower uterine segments, colocalizing with alpha smooth muscle actin. A change in intracellular localization was observed at term labor, where PTGER1 and PTGER4 were predominately associated with the nucleus. Minimal changes in the expression of the PGE2 and PGF2alpha receptor subtypes were observed with gestational age, labor, or between the upper and lower myometrial segments. Receptor expression in maternal and fetal tissues differed between the receptor subtypes; PTGER1 and PTGER4 were predominately expressed in the fetal membranes, PTGER2 was greatest in the myometrium, whereas PTGER3 and PTGFR were similarly expressed in the myometrium and fetal membranes. Myometrial activation through the prostaglandin receptors is perhaps more subtle and may be mediated by a balance between one or several of the prostaglandin receptor subtypes together with other known contraction associated proteins. Lack of coordination in receptor expression between the myometrium and fetal membranes may indicate different regulatory mechanisms between these tissues, or it may suggest a function for these receptors in the amnion and choriodecidua that is independent of that seen in the myometrium.
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MESH Headings
- Amnion/physiology
- Chorion/physiology
- Decidua/physiology
- Female
- Gene Expression Regulation, Developmental
- Gestational Age
- Humans
- Labor, Obstetric
- Myometrium/physiology
- Obstetric Labor, Premature
- Polymerase Chain Reaction/methods
- Pregnancy
- Receptors, Prostaglandin/genetics
- Receptors, Prostaglandin/metabolism
- Receptors, Prostaglandin E/genetics
- Receptors, Prostaglandin E/metabolism
- Receptors, Prostaglandin E, EP1 Subtype
- Receptors, Prostaglandin E, EP2 Subtype
- Receptors, Prostaglandin E, EP3 Subtype
- Receptors, Prostaglandin E, EP4 Subtype
- Uterine Contraction/physiology
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Affiliation(s)
- Peta L Grigsby
- Department of Obstetrics and Gynecology, University of Cincinnati, Medical College, Cincinnati, Ohio 45267, USA.
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Moynihan AT, Hehir MP, Glavey SV, Smith TJ, Morrison JJ. Inhibitory effect of leptin on human uterine contractility in vitro. Am J Obstet Gynecol 2006; 195:504-9. [PMID: 16647683 DOI: 10.1016/j.ajog.2006.01.106] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 01/20/2006] [Accepted: 01/27/2006] [Indexed: 11/23/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate the effects of leptin on human uterine contractility in vitro. STUDY DESIGN Biopsies of human myometrium were obtained at elective cesarean section (n = 18). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous and oxytocin-induced contractions, were exposed to cumulative additions of leptin in the concentration range of 1 nmol/L to 1 micromol/L. Control strips were run simultaneously. Integrals of contractile activity were measured using the PowerLab hardware unit and Chart v3.6 software. RESULTS Leptin exerted a potent and cumulative inhibitory effect on spontaneous and oxytocin-induced contractions compared to control strips. The mean maximal inhibition values were as follows: 46.794 +/- 5.133% (n = 6; P < .001) for spontaneous contractions and 42.323 +/- 3.692% (n = 6; P < .001) for oxytocin-induced contractions. There was an apparent reduction in both frequency and amplitude of contractions. CONCLUSION This physiologic inhibitory effect of leptin on uterine contractility may play a role in the dysfunctional labor process associated with maternal obesity, and the resultant high cesarean section rates.
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Affiliation(s)
- Audrey T Moynihan
- Department of Obstetrics and Gynaecology, Clinical Science Institute, University College Hospital Galway, National University of Ireland, Galway, Ireland
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Doheny HC, Lynch CM, Smith TJ, Morrison JJ. Functional coupling of beta3-adrenoceptors and large conductance calcium-activated potassium channels in human uterine myocytes. J Clin Endocrinol Metab 2005; 90:5786-96. [PMID: 16014404 DOI: 10.1210/jc.2005-0574] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Beta3-adrenoreceptor modulation in human myometrium during pregnancy is linked functionally to myometrial inhibition. Maxi-K+ channels (BK(Ca)) play a significant role in modulating cell membrane potential and excitability. OBJECTIVE This study was designed to investigate the potential involvement of BK(Ca) channel function in the response of human myometrium to beta3-adrenoceptor activation. DESIGN Single and whole-cell electrophysiological BK(Ca) channel recordings from freshly dispersed myocytes were obtained in the presence and absence of BRL37344, a specific beta3-adrenoreceptor agonist. The in vitro effects of BRL37344 on isolated myometrial contractions, in the presence and absence of the specific BK(Ca) channel blocker, iberiotoxin (IbTX), were investigated. SETTING The study was carried out at the Clinical Science Institute. PATIENTS OR OTHER PARTICIPANTS Myometrial biopsies were obtained at elective cesarean delivery. INTERVENTION No intervention was applied. MAIN OUTCOME MEASURES Open state probability of single channel recordings, whole cell currents, and myometrial contractile activity were measured. RESULTS Single-channel recordings identified the BK(Ca) channel as a target of BRL37344. BRL37344 significantly increased the open state probability of this channel in a concentration-dependent manner (control 0.031 +/- 0.004; 50 microM BRL37344 0.073 +/- 0.005 (P < 0.001); and 100 microM BRL37344 0.101 +/- 0.005 (P < 0.001). This effect was completely blocked after preincubation of the cells with 1 microM bupranolol, a nonspecific beta-adrenoreceptor blocker, or 100 nM SR59230a, a specific beta3-adrenoreceptor antagonist. In addition, BRL37344 increased whole-cell currents over a range of membrane potentials, and this effect was reversed by 100 nM IbTX. In vitro isometric tension studies demonstrated that BRL37344 exerted a significant concentration-dependent relaxant effect on human myometrial tissue (P < 0.05), and preincubation of these strips with IbTX attenuated this effect on both spontaneous and oxytocin-induced contractions (44.44 and 57.84% at 10(-5) M, respectively). CONCLUSIONS These findings outline that activation of the BK(Ca) channel may explain the potent uterorelaxant effect of beta3-adrenoreceptor agonists.
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Affiliation(s)
- Helen C Doheny
- Department of Obstetrics and Gynecology, National University of Ireland Galway, Clinical Science Institute, University College Hospital Galway, Galway, Ireland.
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35
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Affiliation(s)
- Caroline de Costa
- Department of Obstetrics and Gynaecology, James Cook University School Of Medicine, Cairns Base Hospital, Cairns, Australia.
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Functional effects of 17alpha-hydroxyprogesterone caproate (17P) on human myometrial contractility in vitro. Reprod Biol Endocrinol 2004; 2:80. [PMID: 15585068 PMCID: PMC539291 DOI: 10.1186/1477-7827-2-80] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Accepted: 12/07/2004] [Indexed: 11/26/2022] Open
Abstract
Background 17alpha-hydroxyprogesterone caproate (17P) administration reportedly improves outcome for women with a previous spontaneous preterm delivery. This study, using in vitro strips of human uterine smooth muscle, aimed to investigate the direct non-genomic effects of 17P on spontaneous and induced contractions in tissues obtained during pregnancy, and in the non-pregnant state. Methods Biopsies of human myometrium were obtained at elective cesarean section, and from hysterectomy specimens, and dissected strips suspended for isometric recordings. The effects of 17P (1 nmol/L -10 micro mol/L) on spontaneous and agonist-induced (oxytocin 0.5 nmol/L for pregnant, phenylephrine 10 μmol/L for non-pregnant) contractions were measured. Integrals of contractile activity, including the mean maximal inhibition values (MMI) observed at the maximal concentration, were compared with those from simultaneously run control strips. Results There was no significant direct effect exerted by 17P on pregnant or non-pregnant human myometrial contractility. The MMI ± SEM for spontaneous contractions in pregnant myometrium was 4.9% ± 7.2 (n = 6; P = 0.309) and for oxytocin-induced contractions was 2.2% ± 1.3 (n = 6; P = 0.128). For non-pregnant myometrium, the MMI ± SEM for spontaneous contractions was 8.8% ± 11.0 (n = 6; P = 0.121) and for phenylephrine induced contractions was -7.9% ± 6.5 (n = 6; P = 0.966). Conclusions The putative benefits of 17P for preterm labor prevention are not achieved, even partially, by a direct utero-relaxant effect. These findings outline the possibility that genomic effects of 17P, achieved over long periods of administration, are required for its reported therapeutic benefits.
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O'Sullivan CJ, Allen NM, O'Loughlin AJ, Friel AM, Morrison JJ. Thrombin and PAR1-activating peptide: effects on human uterine contractility in vitro. Am J Obstet Gynecol 2004; 190:1098-105. [PMID: 15118649 DOI: 10.1016/j.ajog.2003.09.050] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Thrombin enhances uterine contractions in animal models, which is an effect that is mediated through protease-activated receptors. The aims of this study were to investigate the effects of thrombin on spontaneous human uterine contractility in vitro, in tissue obtained in the presence and absence of pregnancy, and to investigate the effects of a specific protease-activated receptor 1-activating peptide on human pregnant myometrial contractility. STUDY DESIGN Isometric recordings were performed under physiologic conditions on myometrial strips that were obtained from elective cesarean delivery and premenopausal hysterectomy specimens. The effects of thrombin (0.5 to 5.0 U/mL) and a specific protease-activated receptor 1-activating peptide (1 nmol/L to 10 micromol/L) on integrals of contractile activity were measured and compared with control values. RESULTS Thrombin exerted a potent stimulatory effect on human myometrial contractility. For pregnant and nonpregnant myometrium, this effect was significant at concentrations of > or =3.0 U/mL and 1.0 U/mL, respectively, with net maximal stimulatory effects of 44.5% (5.0 U/mL, P<.001) and 40.42% (3.0 U/mL, P<.001), respectively. The protease-activated receptor 1-activating peptide also mediated a significant uterotonic effect (55.1% increase) on human pregnant myometrial contractility at 10 micromol/L concentration (P<.001). CONCLUSION This uterotonic effect of thrombin suggests that it may play a role in the pathophysiologic condition of human uterine contractions in association with intrauterine bleeding. The similar uterotonic effect that is elicited by protease-activated receptor 1-activating peptide suggests a major role for protease-activated receptor-1 in the thrombin-mediated contractile effect.
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Affiliation(s)
- Crochan J O'Sullivan
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Clinical Science Institute, University College Hospital Galway, Galway, Ireland
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Myatt L, Lye SJ. Expression, localization and function of prostaglandin receptors in myometrium. Prostaglandins Leukot Essent Fatty Acids 2004; 70:137-48. [PMID: 14683689 DOI: 10.1016/j.plefa.2003.04.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Prostaglandins (PGs) play a role in the initiation and maintenance of labor, acting via specific relaxatory or contractile receptors on myometrium. Myometrial response to addition of PGs may be determined by the type and concentration of receptor expressed. Autoradiographic and ligand binding studies suggest a topographic distribution of receptors between fundus, lower segment, and cervix, and that hormonally regulated changes in expression occur with advancing gestation and labor. These receptors have now been cloned and sequenced allowing molecular studies. Current dogma suggests functional regionalization of the pregnant human uterus occurs with the lower segment displaying a contractile phenotype throughout gestation changing to a relaxatory phenotype at labor to allow passage of the fetal head whereas the upper segment has a relaxatory phenotype throughout most of gestation to accommodate the growing fetus and adopts a contractile phenotype for expulsion at labor. Studies to determine the role of PG receptors in this phenomenon are currently underway.
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Affiliation(s)
- Leslie Myatt
- Deparment of Obstetrics and Gynecology, College of Medicine, University of Cincinnati, PO Box 670526, Cincinnati, OH 45267, USA.
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Monir-Bishty E, Pierce S, Kupittayanant S, Shmygol A, Wray S. The effects of metabolic inhibition on intracellular calcium and contractility of human myometrium. BJOG 2003. [DOI: 10.1111/j.1471-0528.2003.03103.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Noble K, Wray S. The role of the sarcoplasmic reticulum in neonatal uterine smooth muscle: enhanced role compared to adult rat. J Physiol 2002; 545:557-66. [PMID: 12456834 PMCID: PMC2290692 DOI: 10.1113/jphysiol.2002.031732] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2002] [Accepted: 09/20/2002] [Indexed: 11/08/2022] Open
Abstract
Little is known about contractile activity, response to agonists or excitation-contraction coupling in neonatal smooth muscle. We have therefore investigated 10-day rat uterus to better understand these processes, and compared it to adult uterus to elucidate how control of contractility develops. Spontaneous contractions are present in the 10-day neonatal uterus, although they are not as large or as regular as those present in adult tissues. External Ca(2+) entry via L-type Ca(2+) channels is the sole source of Ca(2+) and is essential for the spontaneous activity. The neonatal uterus was responsive to carbachol or prostaglandin F(2alpha) application; it showed a marked stimulation and a clear dissociation between the force and Ca(2+) changes. Such sensitization was not apparent in adult rat myometrium. The sarcoplasmic reticulum (SR) had more releasable Ca(2+) and contributed more to the response to agonists in neonatal compared to adult tissues. Thus, Ca(2+) entry as opposed to SR Ca(2+) release contributed much less to the uterine response to agonists in the neonatal, compared to adult tissues. Inhibition of the SR by cyclopiazonic acid also caused a more vigorous increase in Ca(2+) and contractile activity, particularly frequency, in the neonatal compared to the adult uterus. Taken together these data suggest that: (1) spontaneous activity is already present by day 10, (2) receptor-coupling and excitation-contraction signalling pathways are functional, (3) the SR and Ca(2+) sensitization mechanisms play a more prominent role in the neonate, and (4) there is a shift to a greater reliance on Ca(2+) entry and excitability with development of the myometrium.
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Affiliation(s)
- Karen Noble
- Department of Physiology, The University of Liverpool, Liverpool L69 3BX, UK.
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Dennedy MC, Houlihan DD, McMillan H, Morrison JJ. Beta2- and beta3-adrenoreceptor agonists: human myometrial selectivity and effects on umbilical artery tone. Am J Obstet Gynecol 2002; 187:641-7. [PMID: 12237641 DOI: 10.1067/mob.2002.125277] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate the functional selectivity of the beta(3)-adrenoreceptor agonist BRL 37344 and the beta(2)-adrenoreceptor agonist ritodrine for their putative receptors in human pregnant myometrium in vitro and to examine the possibility that BRL 37344 may exert an effect on other beta-adrenoreceptor subtypes. This study also aimed comparatively to evaluate the in vitro effects of BRL 37344 and ritodrine on human vascular tissue tone. STUDY DESIGN The effects of BRL 37344 (1 nmol/L-100 micromol/L) and ritodrine (1 nmol/L-100 micromol/L) on isometric tension recordings that were performed in isolated myometrial strips that were obtained at elective cesarean delivery and in human umbilical artery rings that were obtained at term were measured. Antagonism of the effects of BRL 37344 and ritodrine in human myometrial tissue was investigated with the antagonists butoxamine (1 micromol/L), propranolol (1 micromol/L), and bupranolol (1 micromol/L). The concentrations that produced a 50% maximal effect, the mean maximal inhibition that was achieved, and the percentage of contractility that was observed were compared. RESULTS Bupranolol (n = 6), but not butoxamine (n = 6) or propranolol (n = 6), antagonized the relaxant effects of BRL 37344 in human pregnant myometrium; all three compounds (n = 6, respectively) antagonized the effects of ritodrine. At concentrations of >1 micromol/L, ritodrine exerted a significantly more potent vasodilatory effect than BRL 37344 on human umbilical artery tone (P <.01). CONCLUSION The relaxant effects of BRL 37344 appear to be mediated solely through the beta(3)-adrenoreceptor agonist, although ritodrine may exert an effect on beta(1)-, beta(2)-, and beta(3)-adrenoreceptor agonists. This and the reduction in vascular tissue effects observed with BRL 37344 suggest that uterine beta(3)-adrenoreceptor modulation may provide a novel scientific approach to tocolysis with fewer vascular adverse effects.
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Affiliation(s)
- Michael C Dennedy
- Department of Obstetrics and Gynaecology, Clinical Sciences Institute, National University of Ireland Galway, University College Hospital
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Oropeza MV, Ponce-Monter H, Villanueva-Tello T, Palma-Aguirre JA, Campos MG. Anatomical differences in uterine sensitivity to prostaglandin F(2alpha) and serotonin in non-pregnant rats. Eur J Pharmacol 2002; 446:161-6. [PMID: 12098598 DOI: 10.1016/s0014-2999(02)01827-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ovarian steroids regulate the sensitivity of a population of uterine receptors to prostaglandin F(2alpha), serotonin and oxytocin. However, the uterine sensitivity to prostaglandin F(2alpha) and oxytocin does not coincide with the estrogen-induced increase in the number of receptors. Anatomical differences affect the uterine sensitivity to agonists. We investigated whether anatomical differences between ovarian and cervical uterine regions modulate the hormone-regulated sensitivity to prostaglandin F(2alpha), serotonin and oxytocin. Non-cumulative concentration-response curves for these agonists were recorded for ovarian and cervical uterine segments from adult ovariectomized rats treated with 17beta-estradiol, 17beta-estradiol+progesterone, or vehicle. The ovarian segments displayed a higher maximal response (E(max)) to prostaglandin F(2alpha) and a lower E(max) to serotonin than the cervical segments. Both uterine segments displayed a similar sensitivity to oxytocin. The ovariectomized controls displayed the highest E(max) and the lowest effective concentration 50 (EC(50)) for oxytocin and prostaglandin F(2alpha). Anatomical differences between ovarian and cervical uterine regions modulate the hormonal regulation of uterine sensitivity to serotonin and prostaglandin F(2alpha) in the non-pregnant rat uterus.
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Affiliation(s)
- Martha V Oropeza
- Unidad de Investigacion en Farmacologia, Hospital de Especialidades, CMN Siglo XXI, Instituto Mexicano del Seguro Social, Apdo. Postal 73-032, Mexico 03020, D.F., Mexico.
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Houlihan DD, Dennedy MC, Morrison JJ. Polyamine effects on human myometrial contractility. Am J Obstet Gynecol 2002; 186:778-83. [PMID: 11967507 DOI: 10.1067/mob.2002.122253] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE This study was undertaken to investigate the effects of the polyamine spermine on human uterine contractility. STUDY DESIGN Under physiologic conditions, an isometric tension recording was performed in isolated myometrial strips from biopsy specimens obtained at elective cesarean delivery (n = 24 specimens) and from premenopausal hysterectomy specimens (n = 6 specimens). The effects of spermine (1 micromol/L-10 mmol/L in cumulative doses) on spontaneous, agonist-induced myometrial contractions were measured, and dose response curves were constructed. The pD(2) (-log EC(50)) values and the maximal inhibition values achieved were compared for spontaneous and agonist-induced contractions. RESULTS Spermine exerted a potent relaxant effect on all spontaneous and agonist-induced myometrial contractions, with mean maximal inhibition values between 62.8% +/- 4.3% and 91.4% +/- 1.8% and pD(2) values between 2.66 +/- 0.23 and 4.01 +/- 0.20. Its inhibitory effect varied significantly with different contraction types (pD(2), P <.05; mean maximal inhibition, P <.001), and it was least potent on BAY K 8644-elicited contractions (pD(2), P <.05; mean maximal inhibition, P <.01). CONCLUSION The polyamine spermine exerts a potent relaxant effect on human uterine tissue. This effect appears to be mediated, at least partially, by calcium antagonism. Polyamines may play a role in the maintenance of uterine quiescence during pregnancy.
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Affiliation(s)
- Diarmaid D Houlihan
- Department of Obstetrics and Gynecology, Clinical Science Institute, National University of Ireland Galway, University College Hospital, Galway, Ireland
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Kupittayanant S, Luckas MJM, Wray S. Effect of inhibiting the sarcoplasmic reticulum on spontaneous and oxytocin-induced contractions of human myometrium. BJOG 2002; 109:289-96. [PMID: 11950184 DOI: 10.1111/j.1471-0528.2002.01110.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE 1. To assess the contribution of the sarcoplasmic reticulum calcium store in the generation of uterine smooth muscle contractions; 2. to evaluate the contribution of calcium induced calcium release or ryanodine gated calcium channels to myometrial force production. DESIGN Laboratory scientific study. METHODS Myometrial strips were obtained from women undergoing elective prelabour caesarean section at term. These were loaded with the calcium sensitive indicator Indo-1 allowing simultaneous assessment of intracellular calcium concentrations and force production. The effect of exposing the strips to ryanodine (which abolishes calcium induced calcium release), caffeine (which activates calcium induced calcium release) and cyclopiazonic acid (which abolishes the sarcoplasmic reticulum calcium store) was examined. RESULTS Exposure to ryanodine had no appreciable effect on either the amplitude or the duration of the myometrial calcium and force transients but did increase the frequency of contractions (139+/-5%). Caffeine did not potentiate force. Cyclopiazonic acid increased frequency, duration and amplitude of both calcium and force transients. The ability of oxytocin to provoke calcium and force transients in the absence of extracellular calcium was abolished by cyclopiazonic acid but not by ryanodine. CONCLUSIONS These results demonstrate that calcium induced calcium release does not play a significant role in human myometrium and that no functioning role for the ryanodine receptors in human myometrial tissue could be shown. These data suggest that the sarcoplasmic reticulum may act to limit contractions and act as a calcium sink, rather than to amplify contractions.
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Affiliation(s)
- S Kupittayanant
- The Physiological Laboratory, The University of Liverpool, UK
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Slattery MM, Brennan C, O'Leary MJ, Morrison JJ. Human chorionic gonadotrophin inhibition of pregnant human myometrial contractility. BJOG 2001; 108:704-8. [PMID: 11467695 DOI: 10.1111/j.1471-0528.2001.00178.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate the effect of human chorionic gonadotrophin (hCG) on pregnant human myometrial contractility in vitro and to determine whether the hCG-elicited effect was oestrogen dependant. METHODS Isometric tension recording was performed under physiological conditions in isolated myometrial strips from biopsies obtained at elective caesarean section. The effect of cumulative additions of hCG (0.001, 0.01, 0.1, 1.0 and 10 iu/mL) on myometrial contractility was evaluated. Secondarily, the contractile activity of pregnant myometrium following hCG exposure was investigated in tissue pre-treated with beta-oestradiol. RESULTS hCG exerted a statistically significant relaxant effect on pregnant human myometrial tissue. The relaxant effect increased with increasing concentrations of hCG from 8.96% (SEM 2.06) (0.001 iu/mL hCG: P < 0.01 ) to a net cumulative total of 58.50% (SEM 3.74) (10 iu/mL hCG; P < 0.01). The relaxant effect was also time-dependant, increasing in magnitude throughout the duration of experiments. Beta-oestradiol did not significantly affect the response of myometrial tissue to hCG. CONCLUSIONS These results clearly demonstrate that hCG exerts a significant concentration-dependant relaxant effect on human myometrial tissue obtained rate in pregnancy. These findings outline an inhibitory physiological role of hCG on human myometrial contractility and raise the possibility of its potential use as a tocolytic.
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Affiliation(s)
- M M Slattery
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, University College Hospital Galway
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Slattery MM, Brennan C, O'Leary MJ, Morrison JJ. Human chorionic gonadotrophin inhibition of pregnant human myometrial contractility. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0306-5456(00)00178-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Beta-3 versus beta-2 adrenergic agonists and preterm labour: in vitro uterine relaxation effects. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0306-5456(00)00147-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Dennedy MC, Friel AM, Gardeil F, Morrison JJ. Beta-3 versus beta-2 adrenergic agonists and preterm labour: in vitro uterine relaxation effects. BJOG 2001; 108:605-9. [PMID: 11426895 DOI: 10.1111/j.1471-0528.2001.00147.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE 1. To investigate the effects of the selective beta-3 adrenoreceptor agonist, BRL 37344, on human pregnant myometrial contractility in vitro. 2. to compare these effects with those of the beta-2 adrenoreceptor agonist, ritodrine. METHODS Isometric tension recording was performed under physiological conditions in isolated myometrial strips from biopsies obtained at elective caesarean section. Following pre-incubation with oxytocin (10(-9) M), the effects of cumulative additions of BRL 37344 or ritodrine (10(-8)-10(-3.5) M) on myometrial contractility were investigated. Results were expressed as -log EC50 (pD2) and mean maximal inhibition achieved for both drug compounds. RESULTS BRL 37344 exerted a concentration dependant relaxant effect on myometrial contractions in all strips exposed [pD2, 7.26 (0.48) (SEM); mean maximal inhibition 61.98 (4.89%); n = 6]. Similarly, ritodrine exerted a concentration dependant inhibition of myometrial contractility in all strips exposed [pD2 = 7.40 (0.28); mean maximal inhibition 59.49 (3.97%); n = 6]. There was no significant difference between calculated pD2 values (P = 0.65) or mean maximal inhibition achieved (P = 0.79). CONCLUSIONS The beta-3 adrenoreceptor agonist BRL 37344 induced relaxation of human myometrial contractions with similar potency to that of the most commonly used tocolytic agent ritodrine. This raises the possibility that the novel beta-3 adrenoreceptor agonists may have potential as therapeutic agents for human preterm labour. In view of their reported reduced cardiovascular side effects their potential clinical use requires further evaluation.
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Affiliation(s)
- M C Dennedy
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, University College Hospital
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