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Locci M, Nazzaro G, Merenda A, Pisaturo ML, Laviscio P, Poppiti R, Miranda M, Stile A, De Placido G. Atosiban vs ritodrine used prophylactically with cerclage in ICSI pregnancies to prevent pre-term birth in women identified as being at high risk on the basis of transvaginal ultrasound scan. J OBSTET GYNAECOL 2009; 26:396-401. [PMID: 16846862 DOI: 10.1080/01443610600719883] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Our objective was to compare the effectiveness and safety of atosiban and ritodrine, in pregnancies obtained by intracytoplasmic sperm injection (ICSI) undergoing cervical cerclage. Data from a prospective study were compared with those from a retrospective study. Sixteen ICSI pregnant women, 20-24 weeks' gestation and maternal age >18 years, received atosiban (bolus dose 6.75 mg i.v., followed by 300 microg/min i.v. for 3 h and 100 microg/min i.v. for 45 h). Cervical cerclage was performed 3 h after starting atosiban. The control group (group B) of 16 ICSI pregnant women were matched and received ritodrine hydrochloride (100-350 microg/min) for 48 h. Cervical cerclage was performed after 24 h. Pre-term rupture of membranes occurred within 48 h of cervical cerclage in one woman receiving atosiban and in four women receiving ritodrine. There was no significant difference in terms of pregnancies not delivered at 48 h (short-term tocolysis) and at 7 days (long-term tocolysis). However, there was a significantly higher incidence of maternal tachycardia with ritodrine compared with atosiban (p < 0.001). The mean gestational age at delivery was significantly higher for atosiban compared with ritodrine (36 vs 33 weeks; p < 0.001). The neonatal outcome was poorer for ritodrine than atosiban, as there were very low birth weight infants (p = 0.008), resulting in lower Apgar scores (p = 0.005) and there were more neonates requiring a long stay in the neonatal intensive care unit (p = 0.005). We conclude that atosiban is associated with a significantly lower incidence of maternal tachycardia and improved neonatal outcome compared with ritodrine.
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Affiliation(s)
- M Locci
- University of Naples Federico II, Naples, Italy.
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Ladds G, Zervou S, Vatish M, Thornton S, Davey J. Regulators of G protein signalling proteins in the human myometrium. Eur J Pharmacol 2009; 610:23-8. [PMID: 19318093 DOI: 10.1016/j.ejphar.2009.03.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 02/26/2009] [Accepted: 03/10/2009] [Indexed: 10/21/2022]
Abstract
The contractile state of the human myometrium is controlled by extracellular signals that promote relaxation or contraction. Many of these signals function through G protein-coupled receptors at the cell surface, stimulating heterotrimeric G proteins and leading to changes in the activity of effector proteins responsible for bringing about the response. G proteins can interact with multiple receptors and many different effectors and are key players in the response. Regulators of G protein signalling (RGS) proteins are GTPase activating proteins for heterotrimeric G proteins and help terminate the signal. Little is known about the function of RGS proteins in human myometrium and we have therefore analysed transcript levels for RGS proteins at various stages of pregnancy (non-pregnant, preterm, term non-labouring, term labouring). RGS2 and RGS5 were the most abundantly expressed isolates in each of the patient groups. The levels of RGS4 and RGS16 (and to a lesser extent RGS2 and RGS14) increased in term labouring samples relative to the other groups. Yeast two-hybrid analysis and co-immunoprecipitation in myometrial cells revealed that both RGS2 and RGS5 interact directly with the cytoplasmic tail of the oxytocin receptor, suggesting they might help regulate signalling through this receptor.
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Affiliation(s)
- Graham Ladds
- Clinical Sciences Research Institute, University of Warwick Medical School, UHCW Campus, Clifford Bridge Road, Coventry CV2 2DX, UK
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3
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Abstract
Preterm birth remains a major cause of perinatal mortality and long term handicap in surviving infants. This is one of the most important clinical problems in Europe and across the world. While some preterm births are iatrogenic, associated with severe complications of pregnancy (e.g. hypertensive disorders, antepartum haemorrhage, infection), or the result of multiple pregnancies following assisted reproduction, a high proportion of preterm births occur following spontaneous preterm labour of unknown cause. Early intervention in this group of women would have a significant impact on neonatal mortality and morbidity figures. However, the endocrine changes preceding parturition in women remain elusive and this makes it difficult to predict spontaneous labour at term, let alone preterm labour. Moreover our understanding of myometrial physiology remains rudimentary, limiting our options to devise improved pharmacological strategies to control uterine contractility when this is indicated. There is a need for concerted European and international research efforts to improve our knowledge of the mechanism of labour in women, to identify diagnostic markers to predict preterm labour and to develop uterine selective drugs to inhibit uterine contractions in a safe and efficient manner. This aim will be achieved by multidisciplinary research efforts from academics and industry, using traditional laboratory and clinical research methods, as well as novel technologies.
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Affiliation(s)
- Andrés López Bernal
- University of Bristol, Clinical Science at South Bristol (Obstetrics and Gynaecology), St Michael's Hospital and Dorothy Hodgkin Building, Bristol, UK.
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Doheny HC, O'Reilly MJ, Sexton DJ, Morrison JJ. THG113.31, a specific PGF2alpha receptor antagonist, induces human myometrial relaxation and BKCa channel activation. Reprod Biol Endocrinol 2007; 5:10. [PMID: 17367527 PMCID: PMC1831777 DOI: 10.1186/1477-7827-5-10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Accepted: 03/16/2007] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND PGF2alpha exerts a significant contractile effect on myometrium and is central to human labour. THG113.31, a specific non-competitive PGF2alpha receptor (FP) antagonist, exerts an inhibitory effect on myometrial contractility. The BKCa channel is ubiquitously encountered in human uterine tissue and plays a significant role in modulating myometrial cell membrane potential and excitability. The objective of this study was to investigate potential BKCa channel involvement in the response of human myometrium to THG113.31. METHODS Single and whole-cell electrophysiological BKCa channel recordings from freshly dispersed myocytes, were investigated in the presence and absence of THG113.31. Functional studies investigated the effects of THG113.31 on isolated spontaneous myometrial contractions, in the presence and absence of the BKCa channel blocker, iberiotoxin. RESULTS Single channel recordings identified the BKCa channel as a target of THG113.31. THG113.31 significantly increased the open state probability of these channels [control 0.023+/-0.006; 10 microM THG113.31 0.087+/-0.012 (P = 0.009); and 50 microM THG113.31 0.1356+/-0.018 (P = 0.001)]. In addition, THG113.31 increased whole-cell BKCa currents over a range of membrane potentials, and this effect was reversed by 100 nanoM IbTX. Isometric tension studies demonstrated that THG113.31 exerted a significant concentration-dependent relaxant effect on human myometrial tissue and pre-incubation of strips with IbTX abolished this effect on spontaneously occurring contractions. CONCLUSION These data suggests that activation of the BKCa channel may contribute, at least partially, to the uterorelaxant effect of THG113.31.
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Affiliation(s)
- Helen C Doheny
- Department of Obstetrics & Gynaecology, National University of Ireland Galway, Clinical Science Institute, University College Hospital Galway, Newcastle Road, Galway, Ireland
| | - Michael J O'Reilly
- Department of Obstetrics & Gynaecology, National University of Ireland Galway, Clinical Science Institute, University College Hospital Galway, Newcastle Road, Galway, Ireland
| | - Donal J Sexton
- Department of Obstetrics & Gynaecology, National University of Ireland Galway, Clinical Science Institute, University College Hospital Galway, Newcastle Road, Galway, Ireland
| | - John J Morrison
- Department of Obstetrics & Gynaecology, National University of Ireland Galway, Clinical Science Institute, University College Hospital Galway, Newcastle Road, Galway, Ireland
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Breuiller-Fouche M, Germain G. Gene and protein expression in the myometrium in pregnancy and labor. Reproduction 2006; 131:837-50. [PMID: 16672349 DOI: 10.1530/rep.1.00725] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Microarray technologies widen our comprehension of the major structural and metabolic transformations which affect the myometrium from the very beginning of pregnancy until parturition. The results are coherent with the mass of information which was accumulated previously, primarily on the basis of studies of selected critical factors. They highlight the activation of precise signaling pathways, some of which may have been previously under evaluated. The remodelling and maturation processes that the myometrium undergoes in pregnancy appear clearly as phenomena which last during the full course of gestation. Comparatively, the onset of labor is perhaps the phenomenon which remains the least well described by these methods of analysis. Nevertheless, genomic studies constitute a necessary first step of orientation and help establishing new links between the generic signaling pathways that are activated during the normal or pathological gestation. These studies also represent an indicative step that will have to be paralleled, in the future, with the results of the systematic proteomic analysis of the myometrium.
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Yurtcu N, Cetin A, Karadas B, Gonca Imir A, Kaya T, Erselcan T, Bagcivan I, Cetin M. Comparison of effects of formoterol and BRL 37344 on isolated term-pregnant rat myometrial strips in vitro. Eur J Pharmacol 2006; 530:263-9. [PMID: 16388799 DOI: 10.1016/j.ejphar.2005.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2005] [Accepted: 11/03/2005] [Indexed: 11/16/2022]
Abstract
This study was designed to compare the effects of beta-adrenoceptor agonists formoterol and BRL 37344 on spontaneous contractions and the levels of cAMP and cGMP of myometrial strips isolated from timed-pregnant rats. Myometrial strips were obtained from term-pregnant Wistar albino rats (n=12), mounted in organ baths and tested for changes in isometric tension in response to formoterol and BRL 37344. We evaluated the effect of increasing concentrations of formoterol and BRL 37344 on oxytocin-induced myometrial contractions and on contractions of myometrial smooth muscle pretreated with metoprolol, ICI 118.551 and SR 59230A (beta1, beta2, beta3-adrenoceptor antagonist, respectively, 10(-6) M). Effects of formoterol and BRL 37344 on cAMP and cGMP levels in isolated myometrial strips (n=6) were evaluated by radioimmunoassay kits. Formoterol (10(-12)-10(-8) M) and BRL 37344 (10(-11)-10(-5) M) concentration-dependently decreased the amplitude of oxytocin-induced contractions. E(max) value (100%) of formoterol was increased significantly more than E(max) value (70.6%) of BRL 37344 (P<0.05), with no change in pD(2) value (9.54+/-0.12 and 9.12+/-0.12, respectively). The inhibition of the amplitude of oxytocin-induced contractions by formoterol was antagonized with ICI 118.551 (10(-6) M), but they were not changed by metoprolol (10(-6) M) or SR 59230A (10(-6) M). The inhibition of the amplitude of oxytocin-induced contractions by BRL 37344 were antagonized with SR 59230A (10(-6) M), but they were not changed by metoprolol (10(-6) M) or ICI 118.551 (10(-6) M). Formoterol and BRL 37344 increased cAMP levels. BRL 37344 increased cGMP levels in BRL 37344 group more than control group, but this increase is less significant than cAMP levels (P>0.05). Formoterol and BRL 37344 decreased amplitude of myometrial contractions with similar potency, but efficacy of formoterol was better than BRL 37344.
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Affiliation(s)
- Nazan Yurtcu
- Department of Obstetrics and Gynecology, Cumhuriyet University School of Medicine, 58140 Sivas, Turkey
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Salomonis N, Cotte N, Zambon AC, Pollard KS, Vranizan K, Doniger SW, Dolganov G, Conklin BR. Identifying genetic networks underlying myometrial transition to labor. Genome Biol 2005; 6:R12. [PMID: 15693941 PMCID: PMC551532 DOI: 10.1186/gb-2005-6-2-r12] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Revised: 12/03/2004] [Accepted: 12/29/2004] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Early transition to labor remains a major cause of infant mortality, yet the causes are largely unknown. Although several marker genes have been identified, little is known about the underlying global gene expression patterns and pathways that orchestrate these striking changes. RESULTS We performed a detailed time-course study of over 9,000 genes in mouse myometrium at defined physiological states: non-pregnant, mid-gestation, late gestation, and postpartum. This dataset allowed us to identify distinct patterns of gene expression that correspond to phases of myometrial 'quiescence', 'term activation', and 'postpartum involution'. Using recently developed functional mapping tools (HOPACH (hierarchical ordered partitioning and collapsing hybrid) and GenMAPP 2.0), we have identified new potential transcriptional regulatory gene networks mediating the transition from quiescence to term activation. CONCLUSIONS These results implicate the myometrium as an essential regulator of endocrine hormone (cortisol and progesterone synthesis) and signaling pathways (cyclic AMP and cyclic GMP stimulation) that direct quiescence via the transcriptional upregulation of both novel and previously associated regulators. With term activation, we observe the upregulation of cytoskeletal remodeling mediators (intermediate filaments), cell junctions, transcriptional regulators, and the coordinate downregulation of negative control checkpoints of smooth muscle contractile signaling. This analysis provides new evidence of multiple parallel mechanisms of uterine contractile regulation and presents new putative targets for regulating myometrial transformation and contraction.
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Affiliation(s)
- Nathan Salomonis
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Nathalie Cotte
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
- Department of Medicine, Cardiovascular Research Institute, University of California, 505 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Alexander C Zambon
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
- Department of Medicine, Cardiovascular Research Institute, University of California, 505 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Katherine S Pollard
- Center for Biomolecular Science and Engineering, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Karen Vranizan
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
- Functional Genomics Laboratory, University of California, Berkeley, CA 94720-3860, USA
| | - Scott W Doniger
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Gregory Dolganov
- Department of Medicine, Cardiovascular Research Institute, University of California, 505 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Bruce R Conklin
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, 513 Parnassus Avenue, San Francisco, CA 94143, USA
- Department of Medicine, Cardiovascular Research Institute, University of California, 505 Parnassus Avenue, San Francisco, CA 94143, USA
- Cellular and Molecular Pharmacology, University of California, 600 16th Street, San Francisco, CA 94143-2140, USA
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Karadas B, Kaya T, Guvenal T, Cetin M, Divrik I, Cetin A. Comparison of the effects of nimesulide and 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl) phenyl-2(5H)-furanone (DFU) on contractions of isolated pregnant human myometrium. Eur J Obstet Gynecol Reprod Biol 2004; 113:172-7. [PMID: 15063955 DOI: 10.1016/j.ejogrb.2003.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2002] [Revised: 03/12/2003] [Accepted: 06/09/2003] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To compare the effects of 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl) phenyl-2(5H)-furanone (DFU) and nimesulide, selective COX-2 inhibitors, on the amplitude and frequency of KCl-, oxytocin-, and PGF(2alpha)-stimulated contractions of isolated pregnant human myometrial strips. METHODS Isolated myometrial strips were obtained from 20 pregnant women undergoing elective cesarean section. These strips were mounted in organ baths for recording of isometric tension. The effects of cumulative concentrations of nimesulide and DFU on KCl-, oxytocin-, and PGF(2alpha)-stimulated myometrial contractions were measured, and values for -log(10)EC(50) and mean maximal inhibition (E(max)) were compared. Nimesulide (10(-8) to 10(-4)M) and DFU (10(-8) to 10(-4)M) inhibited in a concentration-dependent manner the KCl-, oxytocin-, and PGF(2alpha)-stimulated contractions of myometrial strips, with a significant effect on the amplitude (10(-7) to 10(-4)M) and the frequency (10(-6) to 10(-4)M). RESULTS The inhibitor effect of DFU was more potent than nimesulide on KCl-, oxytocin-, and PGF(2alpha)-stimulated myometrial contractions, however, the inhibitor effects of nimesulide and DFU was much greater on KCl-stimulated contractions than on oxytocin- and PGF(2alpha)-stimulated myometrial contractions (P < 0.05). There was no significant difference between E(max) values of nimesulide and DFU in all tissues (P > 0.05). CONCLUSION DFU is a more potent inhibitor than nimesulide on KCl-, oxytocin-, and PGF(2alpha)-stimulated contractions of pregnant human myometrium. The inhibitor effects of nimesulide and DFU were predominantly on KCl-stimulated contractions.
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Affiliation(s)
- Baris Karadas
- Department of Pharmacology, Cumhuriyet University School of Medicine, 58140 Sivas, Turkey
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9
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Andy C. Antibiotic use and preterm labor: attitudes and practice patterns of North Carolina obstetric providers. J Womens Health (Larchmt) 2003; 12:903-9. [PMID: 14670170 DOI: 10.1089/154099903770948131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Despite the reported link between subclinical genital tract infection (GTI) and preterm labor (PTL), it is not certain that treating PTL empirically with antibiotics decreases neonatal morbidity and mortality. This study describes the beliefs of family physicians and nurse-midwives regarding the link between subclinical GTI and PTL and their use of empiric antibiotics to treat spontaneous PTL. METHODS This was a survey of family physicians, family practice residents, and midwives (n = 588) who practice obstetrics in North Carolina. The response rate was 61%. RESULTS Ninety-six percent of providers search for GTI, and 76% believe antibiotics for presumed infection will benefit the neonate. Wide variation in the use of antibiotics exists within groups and between groups of providers. Nurse-midwives are more likely than family physicians to use broad-spectrum antibiotics (p < 0.001). CONCLUSIONS Family physicians and nurse-midwives are uncertain about the optimal management of PTL. Empiric antibiotic use varies widely despite the lack of supportive data.
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MESH Headings
- Adult
- Anti-Bacterial Agents/classification
- Anti-Bacterial Agents/therapeutic use
- Attitude of Health Personnel
- Drug Utilization/statistics & numerical data
- Female
- Health Care Surveys
- Humans
- Infant Mortality
- Infant, Newborn
- Middle Aged
- Midwifery
- North Carolina/epidemiology
- Obstetric Labor, Premature/complications
- Obstetric Labor, Premature/drug therapy
- Physicians, Family
- Practice Patterns, Physicians'/statistics & numerical data
- Pregnancy
- Pregnancy Complications, Infectious/diagnosis
- Pregnancy Complications, Infectious/drug therapy
- Surveys and Questionnaires
- Vaginosis, Bacterial/complications
- Vaginosis, Bacterial/diagnosis
- Vaginosis, Bacterial/drug therapy
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Affiliation(s)
- Camille Andy
- Department of Family Medicine, University of North Carolina, Moses Cone Family Practice Residency Program, 1125 North Church Street, Greensboro, NC 27401, USA.
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10
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Olsen SF, Secher NJ, Björnsson S, Weber T, Atke A. The potential benefits of using fish oil in relation to preterm labor: the case for a randomized controlled trial? Acta Obstet Gynecol Scand 2003; 82:978-82. [PMID: 14616269 DOI: 10.1034/j.1600-0412.2003.00334.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sjúrethur F Olsen
- Maternal Nutrition Group, Danish Epidemiology Science Center, Statens Serum Institut, Copenhagen, Denmark.
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11
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Charpigny G, Leroy MJ, Breuiller-Fouché M, Tanfin Z, Mhaouty-Kodja S, Robin P, Leiber D, Cohen-Tannoudji J, Cabrol D, Barberis C, Germain G. A functional genomic study to identify differential gene expression in the preterm and term human myometrium. Biol Reprod 2003; 68:2289-96. [PMID: 12606369 DOI: 10.1095/biolreprod.102.013763] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The mechanisms that lead to the onset of human parturition are still unknown, although selected critical factors have been identified. To investigate the changes in myometrial gene expression associated with parturition, we used two macroarrays each containing 1176 different complementary human cDNA clones. Methods involving hierarchical clustering and conventional statistical analysis allowed us to generate a profile of genes expression at three stages of late pregnancy: preterm (29 wk amenorrhea); full term, not in labor (38 wk amenorrhea); and full term in labor (39 wk amenorrhea). Only 4% of the genes investigated were differentially expressed between the preterm and term groups (P < 0.05). These genes could be clustered as groups of either down-regulated or up-regulated transcripts. The changes in transcript abundance were particularly marked between the preterm and term stages of gestation, whereas the differences between term not in labor and term in labor were less pronounced. The parturition was characterized by a massive down-regulation of a large panel of developmental, cell adhesion molecule and proliferation-related genes, along with the up-regulation of inflammatory, contraction and apoptosis associated genes. We propose that the mechanisms of parturition consist primarily in the arrest of the processes of myometrial development, a step that might be essential to allow the uterus to recover appropriate contractile function before delivery.
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Affiliation(s)
- G Charpigny
- Physiologie Animale, INRA, Centre de Recherches de Jouy, 78352 Jouy en Josas cedex, France
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12
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Moore F, Asbóth G, López BA. Thromboxane receptor signalling in human myometrial cells. Prostaglandins Other Lipid Mediat 2002; 67:31-47. [PMID: 11789896 DOI: 10.1016/s0090-6980(01)00169-1] [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: 11/24/2022]
Abstract
We measured the effects of stable thromboxane A2 (TXA2) analogues on signalling in cultured human myometrial cells. U46619 and/or IBOP stimulated total inositol phosphates (IPs) and cAMP production, RhoA-associated protein kinase (ROK) activity and elevated intracellular calcium [Ca2+]i. Pretreatment of the cells with pertussis toxin did not inhibit IPs or [Ca2+]i production but the thromboxane receptor (TP) antagonist SQ-29548 did inhibit IPs and cAMP production, the elevation of [Ca2+]i, and the increase in ROK activity. Pretreatment with thapsigargin inhibited [Ca2+]i elevation. TP receptor-stimulated ROK activity was inhibited by the ROK inhibitor Y27632 while ROK activity was enhanced by the caspase 3 inhibitor, Z-DEVD-FMK. TP receptor-stimulated IPs production is additive to prostaglandin F2alpha (FP) or prostaglandin E (EP) receptor-stimulated IPs production and neither FP nor EP receptor-stimulated IPs production is inhibited by SQ29548. Thus cultured human myometrial cells express at least two functional TP receptor subtypes; TPalpha-like (cAMP-stimulating) and TPbeta-like (IPs, [Ca2+] and ROK-stimulating).
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Affiliation(s)
- Frances Moore
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, UK.
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13
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Agha AM, Taha RA. Sildenafil inhibits agonist-evoked rat uterine contractility: influence of guanylyl cyclase inhibition. Eur J Pharmacol 2001; 428:343-8. [PMID: 11689193 DOI: 10.1016/s0014-2999(01)01351-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Sildenafil shows a potent relaxant effect on corpus cavernosum smooth muscles by prolonging cyclic guanosine monophosphate (cGMP) actions. We investigated whether this inhibitory effect of sildenafil was also displayed on the uterine musculature. Isolated uteri of non-pregnant rats were used to measure the possible sildenafil-induced inhibition of contractions evoked by various oxytocic agents, viz., prostaglandin E2, oxytocin and acetylcholine. The relation of these effects to sildenafil action on cGMP was also examined, using methylene blue as a guanylyl cyclase inhibitor. Sildenafil (30 and 100 nM) was found to shift to the right the non-cumulative concentration-response curves of the test agonists in a concentration-dependent manner. The shift was accompanied by a reduction in the maximal response of the tissue to all uterine stimulants selected. Sildenafil also elicited a marked concentration-dependent increase in EC25 of prostaglandin E2, oxytocin and acetylcholine, as compared to their respective control values. Preincubation of the uterine strip with methylene blue (10 microM) reduced the inhibitory effects of sildenafil on oxytocin- and acetylcholine-evoked contractions, at submaximal concentrations of each agonist. The results suggest that sildenafil inhibits the uterotonic potentials of various oxytocic agents and that this effect could be probably related to the drug's action on cGMP.
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Affiliation(s)
- A M Agha
- Department of Pharmacology, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562, Cairo, Egypt.
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14
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Page NM, Woods RJ, Lowry PJ. A regulatory role for neurokinin B in placental physiology and pre-eclampsia. REGULATORY PEPTIDES 2001; 98:97-104. [PMID: 11231038 DOI: 10.1016/s0167-0115(00)00239-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Tachykinin dogma has assumed, so far, that neurokinin B (NKB) is a neuropeptide that is not produced in any peripheral tissue even though its endogenous receptor, NK3, has been found in a number of locations throughout the human body. We have found an abundant source of peripheral NKB in the human and rat placenta. In this review we describe the discovery of NKB in the placenta and examine its possible role in placental physiology and pre-eclampsia (PE). Excessive secretion of placental NKB into the maternal circulation during the third trimester of pregnancy has been found in women suffering from PE. This may provide the key to the cause of the multiple and complex symptoms associated with this potentially life-threatening illness. We also reveal the structural organisation of the human NKB gene for the first time as well as discussing putative mechanisms for its control.
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Affiliation(s)
- N M Page
- School of Animal and Microbial Sciences, The University of Reading, RG6 6AJ, Reading, UK
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