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Assinder SJ, Boumelhem BB. Oxytocin stimulates lipolysis, prostaglandin E 2 synthesis, and leptin secretion in 3T3-L1 adipocytes. Mol Cell Endocrinol 2021; 534:111381. [PMID: 34216640 DOI: 10.1016/j.mce.2021.111381] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 06/01/2021] [Accepted: 06/29/2021] [Indexed: 11/26/2022]
Abstract
A model of oxytocin in the regulation of metabolic status has described one of oxytocin synthesis and release from the neurohypophysis in response to leptin, to suppress further leptin release. In addition, a lipogenic role for oxytocin has been suggested, consistent with an insulinergic action. This model, however, may be incorrect. Oxytocin reduces fat mass in the absence of either leptin or leptin receptor signalling, thereby challenging the interdependence between leptin and oxytocin. An oxytocin induced production of the anti-lipolytic prostaglandin E2 (PGE2) might account for this. Media from 3T3-L1 differentiated adipocytes treated with oxytocin (0-50 nmol.L-1) for 24 hrs were assayed for PGE2, leptin, adiponectin, and glycerol. Harvested cells were analysed for lipid droplet triglyceride and cytosolic free fatty acid (FFA) by flow cytometry, and for altered expression of lipolytic and lipogenic associated gene ontology transcripts by cDNA array. Both PGE2 and leptin secretion were significantly increased by oxytocin treatment whilst adiponectin secretion was not. A significant increase in cytosolic FFA was detected following oxytocin treatment, similar to that determined following treatment with isoproterenol (positive control). A significant increase in glycerol release to the culture media confirmed a lipolytic effect. No enrichment of lipolytic and lipogenic associated gene ontology transcripts was determined, but significant overrepresentation of chemosensory olfactory transcripts was. In conclusion, oxytocin stimulates lipolysis in 3T3-L1 adipocytes, mediated by autocrine/paracrine actions of PGE2 and leptin. To confirm that this response is mediated solely by the oxytocin receptor, further experiments would require those effects being blocked by a specific oxytocin antagonist.
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Affiliation(s)
- Stephen J Assinder
- Discipline of Physiology, School of Medical Science and Bosch Institute, Faculty of Medicine and Health, University of Sydney, Australia.
| | - Badwi B Boumelhem
- Discipline of Physiology, School of Medical Science and Bosch Institute, Faculty of Medicine and Health, University of Sydney, Australia
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2
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Wang P, Wang SC, Li D, Li T, Yang HP, Wang L, Wang YF, Parpura V. Role of Connexin 36 in Autoregulation of Oxytocin Neuronal Activity in Rat Supraoptic Nucleus. ASN Neuro 2019; 11:1759091419843762. [PMID: 31091986 PMCID: PMC6535915 DOI: 10.1177/1759091419843762] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/10/2019] [Accepted: 02/26/2019] [Indexed: 12/24/2022] Open
Abstract
In the supraoptic nucleus (SON), the incidence of dye coupling among oxytocin (OT) neurons increases significantly in nursing mothers. However, the type(s) of connexin (Cx) involved is(are) unknown. In this study, we specifically investigated whether Cx36 plays a functional role in the coupling between OT neurons in the SON of lactating rats. In this brain region, Cx36 was mainly coimmunostained with vasopressin neurons in virgin female rats, whereas in lactating rats, Cx36 was primarily colocalized with OT neurons. In brain slices from lactating rats, application of quinine (0.1 mM), a selective blocker of Cx36, significantly reduced dye coupling among OT neurons as well as the discharge/firing frequency of spikes/action potentials and their amplitude, and transiently depolarized the membrane potential of OT neurons in whole-cell patch-clamp recordings. However, quinine significantly reduced the amplitude, but not frequency, of inhibitory postsynaptic currents in OT neurons; the duration of excitatory postsynaptic currents was reduced but not their frequency and amplitude. Furthermore, the excitatory effect of OT (1 pM) on OT neurons was significantly weakened and delayed by quinine, and burst firing was absent in the presence of this inhibitor. Lastly, Western blotting analysis revealed that the presence of combined, but not alone, quinine and OT significantly reduced the amount of Cx36 in the SON. Thus, Cx36-mediated junctional communication plays a crucial role in autoregulatory control of OT neuronal activity, likely by acting at the postsynaptic sites. The level of Cx36 is modulated by its own activity and the presence of OT.
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Affiliation(s)
- Ping Wang
- Department of Genetics, School of Basic Medical Sciences, Harbin Medical University, China
| | | | - Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, China
| | - Hai-Peng Yang
- The Fourth Affiliated Hospital, Harbin Medical University, China
| | - Liwei Wang
- The Fourth Affiliated Hospital, Harbin Medical University, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, China
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, AL, USA
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Padol AR, Sukumaran SV, Sadam A, Kesavan M, Arunvikram K, Verma AD, Srivastava V, Panigrahi M, Singh TU, Telang AG, Mishra SK, Parida S. Hypercholesterolemia impairs oxytocin-induced uterine contractility in late pregnant mouse. Reproduction 2017; 153:565-576. [DOI: 10.1530/rep-16-0446] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 02/10/2017] [Accepted: 02/27/2017] [Indexed: 12/14/2022]
Abstract
High cholesterol is known to negatively affect uterine contractility inex vivoconditions. The aim of the present study was to reveal the effect ofin vivohypercholesterolemia on spontaneous and oxytocin-induced uterine contractility in late pregnant mouse uterus. Female Swiss albino mice were fed with high cholesterol (HC) diet (0.5% sodium cholate, 1.25% cholesterol and 15% fat) for 6 weeks and then throughout the gestation period after mating. On day 19 of gestation, serum cholesterol level was increased more than 3-fold while triglycerides level was reduced in HC diet-fed animals as compared to control animals fed with a standard diet. In tension experiments, neither the mean integral tension of spontaneous contractility nor the response to CaCl2in high K+-depolarized tissues was altered, but the oxytocin-induced concentration-dependent contractile response in uterine strips was attenuated in hypercholesterolemic mice as compared to control. Similarly, hypercholesterolemia dampened concentration-dependent uterine contractions elicited by a GNAQ protein activator,Pasteurella multocidatoxin. However, it had no effect on endogenous oxytocin level either in plasma or in uterine tissue. It also did not affect the prostaglandin release in oxytocin-stimulated tissues. Western blot data showed a significant increase in caveolin-1 and GRK6 proteins but decline in oxytocin receptor, GNAQ and RHOA protein expressions in hypercholesterolemic mouse uterus. The results of the present study suggest that hypercholesterolemia may attenuate the uterotonic action of oxytocin in late pregnancy by causing downregulation of oxytocin receptors and suppressing the signaling efficacy through GNAQ and RHOA proteins.
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Endometrial prostaglandin synthases, ovarian steroids, and oxytocin receptors in mares with oxytocin-induced luteal maintenance. Theriogenology 2017; 87:193-204. [DOI: 10.1016/j.theriogenology.2016.08.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 08/12/2016] [Accepted: 08/25/2016] [Indexed: 11/22/2022]
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Cesen-Cummings K, Houston KD, Copland JA, Moorman VJ, Walker CL, Davis BJ. Uterine Leiomyomas Express Myometrial Contractile-Associated Proteins Involved in Pregnancy-Related Hormone Signaling. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/107155760301000104] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
| | | | | | | | - Cheryl Lyn Walker
- Laboratory of Women's Health, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina; Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas; University of Texas Medical Branch at Galveston, Galveston, Texas
| | - Barbara J. Davis
- Laboratory of Women's Health, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina; Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas; University of Texas Medical Branch at Galveston, Galveston, Texas; PO Box 12233, Mail Drop A2-01, Research Triangle Park, NC 27709
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Bafor EE, Rowan EG, Edrada-Ebel R. Toward Understanding Myometrial Regulation: Metabolomic Investigation Reveals New Pathways of Oxytocin and Ritodrine Activity on the Myometrium. Reprod Sci 2016; 24:691-705. [DOI: 10.1177/1933719116667224] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Enitome E. Bafor
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Benin, Benin, Edo State, Nigeria
| | - Edward G. Rowan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom
| | - RuAngelie Edrada-Ebel
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom
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Affiliation(s)
- B. F. Mitchell
- Perinatal Research Centre, Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada
| | - Birgit Schmid
- Perinatal Research Centre, Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada
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Slater DM, Zervou S, Thornton S. Prostaglandins and Prostanoid Receptors in Human Pregnancy and Parturition. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/107155760200900302] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Donna M. Slater
- Department of Biological Sciences, University of Warwick, Coventry, United Kingdom
| | | | - Steven Thornton
- Department of Biological Sciences, University of Warwick, Coventry, United Kingdom
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Ding MX, Luo X, Zhang XM, Bai B, Sun JX, Qi HB. Progesterone and nifedipine for maintenance tocolysis after arrested preterm labor: A systematic review and meta-analysis of randomized controlled trial. Taiwan J Obstet Gynecol 2016; 55:399-404. [DOI: 10.1016/j.tjog.2015.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2015] [Indexed: 10/21/2022] Open
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Chawanpaiboon S, Laopaiboon M, Lumbiganon P, Sangkomkamhang US, Dowswell T. Terbutaline pump maintenance therapy after threatened preterm labour for reducing adverse neonatal outcomes. Cochrane Database Syst Rev 2014; 2014:CD010800. [PMID: 24659357 PMCID: PMC11193541 DOI: 10.1002/14651858.cd010800.pub2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND After successful inhibition of threatened preterm labour women are at high risk of recurrent preterm labour. Terbutaline pump maintenance therapy has been used to reduce adverse neonatal outcomes. This review replaces an earlier Cochrane review, published in 2002, which is no longer being updated by the team. OBJECTIVES To determine the effectiveness of terbutaline pump maintenance therapy after threatened preterm labour in reducing adverse neonatal outcomes. SEARCH METHODS We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2014) and reference lists of retrieved studies. SELECTION CRITERIA Randomised controlled trials comparing terbutaline pump therapy with alternative therapy, placebo, or no therapy after arrest of threatened preterm labour. DATA COLLECTION AND ANALYSIS Two review authors independently assessed the studies for inclusion and then extracted data as eligible for inclusion in qualitative and quantitative synthesis (meta-analysis). MAIN RESULTS Four studies were included with a total of 234 women randomised. The overall methodological quality of the included studies was mixed; two studies provided very little information on study methods, there was high sample attrition in one study and in three studies the risk of performance bias was high. We found no strong evidence that terbutaline maintenance therapy offered any advantages over saline placebo or oral terbutaline maintenance therapy in reducing adverse neonatal outcomes by prolonging pregnancy among women with arrested preterm labour. The mean difference (MD) for gestational age at birth was -0.14 weeks (95% confidence interval (CI) -1.66 to 1.38) for terbutaline pump therapy compared with saline placebo pump for two trials combined. One trial reported a risk ratio (RR) of 1.17 (95% CI 0.79 to 1.73) for preterm birth (less than 37 completed weeks) and a RR of 0.97 (95% CI 0.51 to 1.84) of very preterm birth (less than 34 completed weeks) for terbutaline pump compared with saline placebo pump. We found no evidence that terbutaline pump therapy was associated with statistically significant reductions in infant respiratory distress syndrome, or neonatal intensive care unit admission compared with placebo. Compared with oral terbutaline, we found no evidence that pump therapy increased the rate of therapy continuation, or reduced the rate of infant complications or maternal hospital re-admissions. One study suggested that pump therapy resulted in significantly increased weekly cost/woman, $580 versus $12.50 (P < 0.01). No data were reported on long-term infant outcomes. AUTHORS' CONCLUSIONS We found no evidence that terbutaline pump maintenance therapy decreased adverse neonatal outcomes. Taken together with the lack of evidence of benefit, its substantial expense and the lack of information on the safety of the therapy do not support its use in the management of arrested preterm labour. Future use should only be in the context of well-conducted, adequately powered randomised controlled trials.
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Affiliation(s)
- Saifon Chawanpaiboon
- Faculty of Medicine, Siriraj Hospital, Mahidol UniversityDepartment of Obstetrics and Gynaecology2 Prannok, BangkoknoiBangkokThailand10700
| | - Malinee Laopaiboon
- Khon Kaen UniversityDepartment of Biostatistics and Demography, Faculty of Public HealthKhon KaenThailand40002
| | - Pisake Lumbiganon
- Khon Kaen UniversityDepartment of Obstetrics and Gynaecology, Faculty of Medicine123 Mitraparb RoadAmphur MuangKhon KaenThailand40002
| | - Ussanee S Sangkomkamhang
- Khon Kaen HospitalDepartment of Obstetrics and GynaecologySrichan RoadMaungKhon KaenThailand40000
| | - Therese Dowswell
- The University of LiverpoolCochrane Pregnancy and Childbirth Group, Department of Women's and Children's HealthFirst Floor, Liverpool Women's NHS Foundation TrustCrown StreetLiverpoolUKL8 7SS
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Chawanpaiboon S, Laopaiboon M, Lumbiganon P, Sangkomkamhang US, Dowswell T. Terbutaline pump maintenance therapy after threatened preterm labour for reducing adverse neonatal outcomes. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2013. [DOI: 10.1002/14651858.cd010800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Nonsocial functions of hypothalamic oxytocin. ISRN NEUROSCIENCE 2013; 2013:179272. [PMID: 24967304 PMCID: PMC4045544 DOI: 10.1155/2013/179272] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 04/23/2013] [Indexed: 01/06/2023]
Abstract
Oxytocin (OXT) is a hypothalamic neuropeptide composed of nine amino acids. The functions of OXT cover a variety of social and nonsocial activity/behaviors. Therapeutic effects of OXT on aberrant social behaviors are attracting more attention, such as social memory, attachment, sexual behavior, maternal behavior, aggression, pair bonding, and trust. The nonsocial behaviors/functions of brain OXT have also received renewed attention, which covers brain development, reproduction, sex, endocrine, immune regulation, learning and memory, pain perception, energy balance, and almost all the functions of peripheral organ systems. Coordinating with brain OXT, locally produced OXT also involves the central and peripheral actions of OXT. Disorders in OXT secretion and functions can cause a series of aberrant social behaviors, such as depression, autism, and schizophrenia as well as disturbance of nonsocial behaviors/functions, such as anorexia, obesity, lactation failure, osteoporosis, diabetes, and carcinogenesis. As more and more OXT functions are identified, it is essential to provide a general view of OXT functions in order to explore the therapeutic potentials of OXT. In this review, we will focus on roles of hypothalamic OXT on central and peripheral nonsocial functions.
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Voltolini C, Torricelli M, Conti N, Vellucci FL, Severi FM, Petraglia F. Understanding Spontaneous Preterm Birth. Reprod Sci 2013; 20:1274-92. [DOI: 10.1177/1933719113477496] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Chiara Voltolini
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Michela Torricelli
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Nathalie Conti
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Francesca L. Vellucci
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Filiberto M. Severi
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Felice Petraglia
- Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
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Diestrus administration of oxytocin prolongs luteal maintenance and reduces plasma PGFM concentrations and endometrial COX-2 expression in mares. Theriogenology 2013; 79:616-24. [DOI: 10.1016/j.theriogenology.2012.11.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 11/12/2012] [Accepted: 11/12/2012] [Indexed: 11/21/2022]
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15
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Oxytocin promotes bone formation during the alveolar healing process in old acyclic female rats. Arch Oral Biol 2012; 57:1290-7. [DOI: 10.1016/j.archoralbio.2012.03.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/10/2012] [Accepted: 03/31/2012] [Indexed: 11/19/2022]
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16
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Vrachnis N, Malamas FM, Sifakis S, Tsikouras P, Iliodromiti Z. Immune aspects and myometrial actions of progesterone and CRH in labor. Clin Dev Immunol 2011; 2012:937618. [PMID: 22028729 PMCID: PMC3199111 DOI: 10.1155/2012/937618] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 08/17/2011] [Indexed: 01/12/2023]
Abstract
Progesterone and corticotropin-releasing hormone (CRH) have a critical role in pregnancy and labor, as changes related to these hormones are crucial for the transition from myometrial quiescence to contractility. The mechanisms related to their effect differ between humans and other species, thus, despite extensive research, many questions remain to be answered regarding their mediation in human labor. Immune responses to progesterone and CRH are important for labor. Progesterone acts as an immunomodulator which controls many immune actions during pregnancy, and its withdrawal releases the inhibitory action on inflammatory pathways. In humans, a "functional" progesterone withdrawal occurs with onset of labor through changes in progesterone metabolism, progesterone receptors, and other molecules that either facilitate or antagonize progesterone function. Placental CRH acts on the fetal pituitary-adrenal axis to stimulate adrenal production of androgens and cortisol and also acts directly on myometrial cells via its receptors. CRH also affects inflammatory signals and vice versa. Interactions between progesterone and CRH additionally occur during labor. We describe the role of these two hormones in human myometrium and their interactions with the immune system during labor.
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Affiliation(s)
- Nikolaos Vrachnis
- 2nd Department of Obstetrics and Gynecology, University of Athens Medical School, Aretaieio Hospital, 11528 Athens, Greece.
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17
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Vrachnis N, Malamas FM, Sifakis S, Deligeoroglou E, Iliodromiti Z. The oxytocin-oxytocin receptor system and its antagonists as tocolytic agents. Int J Endocrinol 2011; 2011:350546. [PMID: 22190926 PMCID: PMC3235456 DOI: 10.1155/2011/350546] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Accepted: 09/25/2011] [Indexed: 12/29/2022] Open
Abstract
Oxytocin, a hormone involved in numerous physiologic processes, plays a central role in the mechanisms of parturition and lactation. It acts through its receptor, which belongs to the G-protein-coupled receptor superfamily, while Gq/phospholipase C (PLC)/inositol 1,4,5-triphosphate (InsP3) is the main pathway via which it exerts its action in the myometrium. Changes in receptor levels, receptor desensitization, and locally produced oxytocin are factors that influence the effect of oxytocin on uterine contractility in labor. Activation of oxytocin receptor causes myometrial contractions by increasing intracellular Ca(+2) and production of prostaglandins. Since oxytocin induces contractions, the inhibition of its action has been a target in the management of preterm labor. Atosiban is today the only oxytocin receptor antagonist that is available as a tocolytic. However, the quest for oxytocin receptor antagonists with a better pharmacological profile has led to the synthesis of peptide and nonpeptide molecules such as barusiban, retosiban, L-368,899, and SSR-126768A. Many of these oxytocin receptor antagonists are used only as pharmacological tools, while others have tocolytic action. In this paper, we summarize the action of oxytocin and its receptor and we present an overview of the clinical and experimental data of oxytocin antagonists and their tocolytic action.
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Affiliation(s)
- Nikolaos Vrachnis
- 2nd Department of Obstetrics and Gynecology, Aretaieio Hospital, University of Athens Medical School, 11526 Athens, Greece
- *Nikolaos Vrachnis:
| | - Fotodotis M. Malamas
- 1st Department of Obstetrics and Gynecology, Alexandra Hospital, University of Athens Medical School, 11526 Athens, Greece
| | - Stavros Sifakis
- Department of Obstetrics and Gynaecology, University Hospital of Heraklion, 71110 Heraklion, Crete, Greece
| | - Efthymios Deligeoroglou
- 2nd Department of Obstetrics and Gynecology, Aretaieio Hospital, University of Athens Medical School, 11526 Athens, Greece
| | - Zoe Iliodromiti
- 2nd Department of Obstetrics and Gynecology, Aretaieio Hospital, University of Athens Medical School, 11526 Athens, Greece
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Franczak A, Bogacki M. Local and systemic effects of embryos on uterine tissues during early pregnancy in pigs. J Reprod Dev 2009; 55:262-72. [PMID: 19293562 DOI: 10.1262/jrd.20148] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the pig, the periimplantation period is critical for successful establishment of pregnancy. We studied the influence of embryos on oxytocin (OT) and progesterone (P(4)) regulated endometrial and myometrial secretion of 1) luteotrophic prostaglandin E(2) (PGE(2)) and 2) luteolytic prostaglandin F(2alpha) and its metabolite (PGFM) on days 12-14 of pregnancy in pigs. We used unilaterally pregnant pigs created by a surgical procedure in which one uterine horn remained intact and the second horn was cut transversely so that part of the horn was detached from the uterine body. The animals were divided into two groups, inseminated gilts (days 12-14 of pregnancy, n=6) and uninseminated cyclic gilts, which were used as controls (days 12-14 of estrous cycle, n=5). Embryos developed only in the patent part of the uterus and not in the occluded horn. The abundance of OTR mRNA was increased in the endometrium and decreased in the myometrium of the gravid uterine horn in the pregnant pigs compared with the non-gravid uterine horn or either uterine horn in the cyclic pigs, indicative of a local effect of the conceptus. The presence of embryos in the uterine horn during the periimplantation period determines endometrial metabolism of PGF(2alpha) and the local response of the endometrium to OT and P(4). OT stimulates PGF(2alpha) secretion and PGFM accumulation in endometrial cultures only from the non-gravid uterine horn and controls PGE(2) secretion from the endometrium and myometrium in the pregnant gilts. The results indicate a more systemic affect of pregnancy on the uterine response to OT and a possibly the local effect of the conceptus in promoting progesterone's inhibition of OT-stimulated PGE(2) secretion and uterine metabolism of PGF(2alpha).
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Affiliation(s)
- Anita Franczak
- Department of Animal Physiology, Faculty of Biology, University of Warmia and Mazury in Olsztyn, Poland.
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Mansfeld J, Ulbrich-Hofmann R. Secretory phospholipase A2-α from Arabidopsis thaliana: functional parameters and substrate preference. Chem Phys Lipids 2007; 150:156-66. [PMID: 17692835 DOI: 10.1016/j.chemphyslip.2007.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 07/03/2007] [Accepted: 07/04/2007] [Indexed: 10/23/2022]
Abstract
The secretory phospholipase A2-alpha from Arabidopsis thaliana (AtsPLA2-alpha), being one of the first plant sPLA2s obtained in purified state, has been characterised with respect to substrate preference and optimum conditions of catalysis. The optima of pH, temperature, and calcium concentration were similar to the parameters of secretory PLA2s from animals. However, substrate preferences markedly differed. In contrast to pancreatic PLA2s, AtsPLA2-alpha preferred zwitterionic phospholipids, and showed lower activity toward anionic phospholipids. In substrates with two identical fatty acid chains, AtsPLA2-alpha showed optimum activity toward phospholipids with decanoyl groups. In substrates with palmitoyl groups in sn-1 position, acyl chains with higher degree of unsaturation in sn-2 position were preferred, excluding arachidonic acid, showing the evolutionary adaptation of the enzyme to substrate composition in plants. Km values for short chain phospholipids were comparable to sPLA2s from animals, whereas k cat values were much smaller and interfacial activation was less important.
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Affiliation(s)
- Johanna Mansfeld
- Institute of Biochemistry and Biotechnology, Martin-Luther University Halle-Wittenberg, D-06120 Halle, Germany.
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Terzidou V. Preterm labour. Biochemical and endocrinological preparation for parturition. Best Pract Res Clin Obstet Gynaecol 2007; 21:729-56. [PMID: 17616441 DOI: 10.1016/j.bpobgyn.2007.05.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Preterm delivery is a common obstetric problem occurring in about 1 in 10 of all births. Preterm babies have a high risk of morbidity and mortality. Such births account for 75% of all major neonatal problems. At the other end of the spectrum, prolonged pregnancy is also a subject of concern because it too is associated with increased fetal morbidity and mortality. Despite extensive research, the mechanisms that control the length of human pregnancy and signal the onset of labour have not been fully determined. This chapter will discuss basic principles in the biology of parturition and the regulation of contraction-associated proteins including the oxytocin receptor. The major pathways regulating contractions and the transcriptional regulation of the main genes that are known to be involved in the onset of labour and parturition will be examined. Some new potentially therapeutic strategies for the biochemical management of preterm labour will be discussed.
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Affiliation(s)
- Vasso Terzidou
- Parturition Research Group, Faculty of Medicine, Imperial College London, Institute of Reproductive and Developmental Biology, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
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Reversi A, Cassoni P, Chini B. Oxytocin receptor signaling in myoepithelial and cancer cells. J Mammary Gland Biol Neoplasia 2005; 10:221-9. [PMID: 16807802 DOI: 10.1007/s10911-005-9583-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Oxytocin (OT) plays a crucial role as a mediator of breast myoepithelial cell contraction, the process responsible for the ejection of milk during lactation, and is also involved in myoepithelial cell proliferation and postpartum mammary gland proliferation. Furthermore, although a number of breast cancer cells have oxytocin receptors (OTRs), it has been reported that OT stimulates, inhibits, or has no effect on cell proliferation. As these different effects seem to be mediated by different signaling pathways elicited by OTR stimulation, we here review the regulation of OTR signaling in different cell systems and discuss how understanding the molecular basis of receptor coupling specificity has become extremely important for understanding the role played by OTRs in regulating cell growth.
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Affiliation(s)
- Alessandra Reversi
- CNR Institute of Neuroscience, Cellular and Molecular Pharmacology Section, Milan, Italy
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Shimizu T, Okada S, Yamaguchi-Shima N, Yokotani K. Brain phospholipase C–diacylglycerol lipase pathway is involved in vasopressin-induced release of noradrenaline and adrenaline from adrenal medulla in rats. Eur J Pharmacol 2004; 499:99-105. [PMID: 15363956 DOI: 10.1016/j.ejphar.2004.07.087] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 07/12/2004] [Accepted: 07/15/2004] [Indexed: 02/02/2023]
Abstract
Recently, we reported that intracerebroventricularly (i.c.v.) administered arginine-vasopressin evokes the release of noradrenaline and adrenaline from adrenal medulla by brain thromboxane A2-mediated mechanisms in rats. These results suggest the involvement of brain arachidonic acid in the vasopressin-induced activation of the central adrenomedullary outflow. Arachidonic acid is released mainly by two pathways: phospholipase A2 (PLA2)-dependent pathway; phospholipase C (PLC)- and diacylglycerol lipase-dependent pathway. In the present study, therefore, we attempted to identify which pathway is involved in the vasopressin-induced release of both catecholamines from adrenal medulla using urethane-anesthetized rats. Vasopressin (0.2 nmol/animal, i.c.v.)-induced elevation of plasma noradrenaline and adrenaline was dose-dependently reduced by neomycin [0.28 and 0.55 micromol (250 and 500 microg)/animal, i.c.v.] and 1-[6-[[(17beta)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U-73122) [5 and 10 nmol (2.3 and 4.6 microg)/animal, i.c.v.] (inhibitors of PLC), and also by 1,6-bis(cyclohexyloximinocarbonylamino)hexane (RHC-80267) [1.3 and 2.6 micromol (500 and 1000 microg)/animal, i.c.v.] (an inhibitor of diacylglycerol lipase). On the other hand, mepacrine [1.1 and 2.2 micromol (500 and 1000 microg)/animal, i.c.v.] (an inhibitor of PLA2) was largely ineffective on the vasopressin-induced elevation of plasma catecholamines. These results suggest that vasopressin evokes the release of noradrenaline and adrenaline from adrenal medulla by the brain PLC- and diacylglycerol lipase-dependent mechanisms in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Neuropharmacology, Program of Neural Integration, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
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Abstract
Prostaglandins have long been thought to play important roles in the mechanism of parturition. Here we review the involvement of prostaglandins in myometrial and cervical functions with emphasis on human labor and birth. In addition, the cellular sources of prostaglandins as well as their interactions with various other endocrine, paracrine and physical factors, such as oxytocin, corticotropin releasing hormone, nitric oxide, platelet activating factor, cytokines, endothelin and stretch are also addressed together with their potential role in the molecular reorganization of cervical structure associated with labor and delivery. Finally, the premier role of progesterone in pregnancy maintenance and parturition is juxtaposed with the proposed "fine-tuning", modulatory role of prostaglandins and the above listed factors in the regulation of parturition.
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Affiliation(s)
- Frank Hertelendy
- Department of Obstetrics, Gynecology and Women's Health, St. Mary's Health Center, St. Louis University, School of Medicine, St. Louis, MO 63117, USA.
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Abstract
This review will discuss the status of research related to sexual arousability. It will also present a model for sexual arousability based on current knowledge of steroids effects at the membranes of cells. Steroids have multiple rapid actions that are suggested to result from actions at membrane-associated receptors. When stimulated by steroids these receptors alter G-protein coupling in a manner unique to this complex. Initial stimulation of the receptors by steroids alters the coupling pattern of G-proteins and of other binding sites associated with the complex. This change in G-protein coupling is a stable alteration and thus may serve as a long-term change in the system, which is a requirement of sexual arousability. Stimulation of this receptor system by a surge of oxytocin at ejaculation or orgasm then decouples the G-protein and reduces arousability. Sex hormone binding globulin may be an important ligand at this complex. This model suggests completely new relationships among steroids and their receptors that may complement or diverge from actions at known intracellular receptors.
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Affiliation(s)
- Jack D Caldwell
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, IL 61107-1897, USA.
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Burbach JP, Luckman SM, Murphy D, Gainer H. Gene regulation in the magnocellular hypothalamo-neurohypophysial system. Physiol Rev 2001; 81:1197-267. [PMID: 11427695 DOI: 10.1152/physrev.2001.81.3.1197] [Citation(s) in RCA: 240] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The hypothalamo-neurohypophysial system (HNS) is the major peptidergic neurosecretory system through which the brain controls peripheral physiology. The hormones vasopressin and oxytocin released from the HNS at the neurohypophysis serve homeostatic functions of water balance and reproduction. From a physiological viewpoint, the core question on the HNS has always been, "How is the rate of hormone production controlled?" Despite a clear description of the physiology, anatomy, cell biology, and biochemistry of the HNS gained over the last 100 years, this question has remained largely unanswered. However, recently, significant progress has been made through studies of gene identity and gene expression in the magnocellular neurons (MCNs) that constitute the HNS. These are keys to mechanisms and events that exist in the HNS. This review is an inventory of what we know about genes expressed in the HNS, about the regulation of their expression in response to physiological stimuli, and about their function. Genes relevant to the central question include receptors and signal transduction components that receive and process the message that the organism is in demand of a neurohypophysial hormone. The key players in gene regulatory events, the transcription factors, deserve special attention. They do not only control rates of hormone production at the level of the gene, but also determine the molecular make-up of the cell essential for appropriate development and physiological functioning. Finally, the HNS neurons are equipped with a machinery to produce and secrete hormones in a regulated manner. With the availability of several gene transfer approaches applicable to the HNS, it is anticipated that new insights will be obtained on how the HNS is able to respond to the physiological demands for its hormones.
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Affiliation(s)
- J P Burbach
- Rudolf Magnus Institute for Neurosciences, Section of Molecular Neuroscience, Department of Medical Pharmacology, University Medical Center Utrecht, Utrecht, The Netherlands.
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