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YANG L, CHAI CZ, YUE XY, YAN Y, KOU JP, CAO ZY, YU BY. Ge-Gen Decoction attenuates oxytocin-induced uterine contraction and writhing response: potential application in primary dysmenorrhea therapy. Chin J Nat Med 2016; 14:124-132. [DOI: 10.1016/s1875-5364(16)60005-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Indexed: 01/02/2023]
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Guedes-Martins L, Gaio R, Saraiva J, Cerdeira S, Matos L, Silva E, Macedo F, Almeida H. Reference ranges for uterine artery pulsatility index during the menstrual cycle: a cross-sectional study. PLoS One 2015; 10:e0119103. [PMID: 25742286 PMCID: PMC4351196 DOI: 10.1371/journal.pone.0119103] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 01/28/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Cyclic endometrial neoangiogenesis contributes to changes in local vascular patterns and is amenable to non-invasive assessment with Doppler sonography. We hypothesize that the uterine artery (UtA) impedance, measured by its pulsatility index (PI), exhibits a regular pattern during the normal menstrual cycle. Therefore, the main study objective was to derive normative new day-cycle-based reference ranges for the UtA-PI during the entire cycle from days 1 to 34 according to the isolated time effect and potential confounders such as age and parity. METHODS From January 2009 to December 2012, a cross-sectional study of 1,821 healthy women undergoing routine gynaecological ultrasound was performed. The Doppler flow of the right and left UtA-PI was studied transvaginally by colour and pulsed Doppler imaging. The mean right and left values and the presence or absence of a bilateral protodiastolic notch were recorded. Reference intervals for the PI according to the cycle day were generated by classical linear regression. RESULTS The majority of patients (97.5%) presented unilateral or bilateral UtA notches. The crude 5th, 50th, and 95th reference percentile curves of the UtA-PI at 1-34 days of the normal menstrual cycle were derived. In all curves, a progressive significant decrease occurred during the first 13 days, followed by an increase and recovery in the UtA-PI. The adjusted 5th, 50th, and 95th reference percentile curves for the effects of age and parity were also obtained. These two conditions generated an approximately identical UtA-PI pattern during the cycle, except with small but significant reductions at the temporal extremes. CONCLUSIONS The median, 5th, and the 95th percentiles of the UtA-PI decrease during the first third of the menstrual cycle and recover to their initial values during the last two thirds of the cycle. The rates of decrease and recovery depend significantly on age and parity.
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Affiliation(s)
- Luís Guedes-Martins
- Department of Experimental Biology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, 4150-180 Porto, Portugal; Centro Hospitalar do Porto EPE, Departamento da Mulher e da Medicina Reprodutiva, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal
| | - Rita Gaio
- Department of Mathematics, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; CMUP-Centre of Mathematics, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Joaquim Saraiva
- Department of Experimental Biology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal; Centro Hospitalar do Porto EPE, Departamento da Mulher e da Medicina Reprodutiva, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal; Obstetrics-Gynecology, Private Hospital Trofa, 4785-409 Trofa, Portugal
| | - Sofia Cerdeira
- Gulbenkian Program for Advanced Medical Education, 1067-001 Lisbon, Portugal; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Liliana Matos
- Department of Experimental Biology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, 4150-180 Porto, Portugal; Faculty of Nutrition and Food Sciences, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Elisabete Silva
- Department of Experimental Biology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, 4150-180 Porto, Portugal
| | - Filipe Macedo
- Department of Cardiology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Henrique Almeida
- Department of Experimental Biology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, 4150-180 Porto, Portugal; Obstetrics-Gynecology, Hospital-CUF Porto, 4100-180 Porto, Portugal
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Shih HC, Hsu CS, Yang LL. In vitro study of the tocolytic effect of oroxylin A from Scutellaria baicalensis root. J Biomed Sci 2009; 16:27. [PMID: 19272127 PMCID: PMC2656494 DOI: 10.1186/1423-0127-16-27] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 03/04/2009] [Indexed: 12/04/2022] Open
Abstract
Scutellariae Radix is one of the well-known tocolytic Chinese herbs. Oroxylin A is isolated from the root of Scutellaria baicalensis. The main syndrome of preterm birth is caused by uterus contractions from excitatory factors. Administration of tocolytic agents is a strategy to prevent the occurrence of preterm births. The aim of this study was to investigate the effects of oroxylin A on contractions of uterine strips isolated from non-pregnant female Wistar rats (250~350 g). Contractions of the uterus were induced with acetylcholine (Ach) (1 μM), PGF2α (0.1 μM), oxytocin (10-3 U/ml), KCl (56.3 mM), tetraethylammonium (TEA; 1 and 10 mM), 4-aminopyridine (4-AP; 5 mM), glipizide (30 μM), a nitric oxide synthase (NOS) inhibitor (LNNA; 10-3M), a β-receptor blocker (propranolol; 10 μM), and a cyclooxygenase inhibitor (indomethacin; 60 μM). The inhibitory effects of the amplitude and frequency of spontaneous contractions by oroxylin A were antagonized with Ach (IC50 22.85 μM), PGF2α (IC5027.28 μM), oxytocin (IC50 12.34 μM), TEA; 1 and 10 mM (IC50 52.73 and 76.43 μM), 4-AP (IC50 67.16 μM), and glipizide (IC5027.53 μM), but oroxylin A was not influenced by Ca2+-free medium, LNNA, propranolol, or indomethacin. Otherwise, oroxylin A-mediated relaxation of the rat uterus might occur through opening of uterine calcium-dependent potassium channels or adenosine triphosphate potassium channel activation. This suggests that oroxylin A is the tocolytic principle constituent of Scutellariae Radix, and oroxylin A may provide a lead compound for new tocolytic drug development in the future.
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Affiliation(s)
- Huey-Chuan Shih
- School of Pharmacy, College of Pharmacy, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan.
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Bolle P, Mastrangelo S, Perrone F, Evandri MG. Estrogen-like effect of a Cimicifuga racemosa extract sub-fraction as assessed by in vivo, ex vivo and in vitro assays. J Steroid Biochem Mol Biol 2007; 107:262-9. [PMID: 17689956 DOI: 10.1016/j.jsbmb.2007.03.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 03/12/2007] [Indexed: 11/21/2022]
Abstract
Black cohosh (Cimicifuga racemosa) is used in the treatment of painful menstruation and menopausal symptoms. Data about the nature of the active compounds and mechanism(s) of action are still controversial, chiefly with respect to its estrogenic activity. This work aimed to assess the possible estrogenic activity of a commercial dry hydro-alcoholic extract of C. racemosa and its hydrophilic and lipophilic sub-fractions on in vivo, ex vivo, and in vitro assays. In a yeast estrogen screen, only the lipophilic sub-fraction was able to activate the human estrogen receptor alpha, with a lower potency but comparable efficacy to that of 17 beta-estradiol. Neither the total extract nor the lipophilic sub-fraction showed an in vivo uterotrophic effect in 21-day-old rats. Uterine tissues obtained ex vivo from C. racemosa treated animals were generally much less sensitive to oxytocin, prostaglandin F(2alpha,) and bradykinin than tissues obtained from estradiol valerate treated rats. The lipophilic sub-fraction, instead, induced a dose-dependent inhibitory activity on the in vitro response to oxytocin, prostaglandin F(2alpha,) and bradykinin of uterine horns from naïve 28-day-old rats, with a potency rate close to 1:30 of that of 17 beta-estradiol. Reported results confirm the effectiveness of C. racemosa in menstrual distress and further emphasize the possibility that lipophilic constituents bind to an as yet not identified estrogen receptor, likely inversely involved in inflammation.
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Affiliation(s)
- P Bolle
- Department of Human Physiology and Pharmacology, University La Sapienza Ple. Aldo Moro, 5-00185 Rome, Italy.
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Hsu CS, Yang JK, Yang LL. Effect of "Dang-Qui-Shao-Yao-San" a Chinese medicinal prescription for dysmenorrhea on uterus contractility in vitro. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2006; 13:94-100. [PMID: 16360938 DOI: 10.1016/j.phymed.2004.06.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2003] [Accepted: 06/12/2004] [Indexed: 05/05/2023]
Abstract
Dysmenorrhea is directly related to elevated level of prostaglandin F(2)alpha (PGF(2)alpha), and is treated with nonsteroid anti-inflammatory drugs. Though efficacy of the latter is rapid, the effect is temporary, and they cause many side effects to the liver, kidney and digestive system. Because of this, Chinese medicinal therapy is being considered as a feasible alternative medicine. In this study, Dang-Qui-Shao-Yao-San (DQSYS), one of Chinese medicinal prescriptions was selected. A 50% alcohol solution was used to extract the active ingredients and create a freeze-dried product. Using rat uterine smooth muscle in vitro, DQSYS was used to suppress spontaneous contractions and PGF(2)alpha induced contractions. Then acetylcholine, ergonovine, propranolol, oxytocin and KCl were used to analyze the physiological mechanisms. The results show that DQSYS has the antagonistic action on both PGF(2)alpha and Ach induced uterine contraction. Furthermore, it has the antagonistic effect on contraction caused by KCl-depolarization. These actions may be the major mechanism of the beneficial effect of Chinese prescription in treating dysmenorrhea.
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Affiliation(s)
- C-S Hsu
- Department of Obstetrics and Gynecology, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan
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Hsu CS, Yang JK, Yang LL. Effect of a dysmenorrhea Chinese medicinal prescription on uterus contractility in vitro. Phytother Res 2003; 17:778-83. [PMID: 12916077 DOI: 10.1002/ptr.1235] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Dysmenorrhea is a common gynecologic complaint. After their first menstrual period, 30%-60% of American women suffer from some level of discomfort. It is estimated that 6 billion work hours are lost in this manner every year in the United States which equals an economic loss of nearly US$200 million. Dysmenorrhea is not only a problem for women but also one which affects quality of life and even reduces productivity in general. Dysmenorrhea is directly related to elevated levels of PGF2alpha (prostaglandins F2alpha) and is treated using nonsteroid anti-inflammatory drugs in Western medicine. Though efficacy of the latter is rapid, there are many side effects to the liver, kidney, and digestive system. The anti-inflammatory effect is temporary, and such drugs are unable to provide a long-term cure. Because of this, Chinese medicinal therapy is being considered as a feasible alternative medicine. In this study, Wen-Jing Tang (one of the dysmenorrhea Chinese medicinal prescriptions) was selected. A 50% alcoholic solution was used to extract active ingredients and create a freeze-dried product. At first, Wen-Jing Tang was used to suppress spontaneous contractions and prostaglandins F2alpha-induced contractions of rat uterine smooth muscle in vitro. Then, an assessment was performed to determine the mechanism of the prescription. Acetylcholine, ergonovine, propranolol, oxytocin, and KCl were used to analyze the physiological mechanisms of WJT. The results show that antagonism of both PGF2alpha and ACh are the major mechanisms for treating dysmenorrhea by Wen-Jing Tang. Furthermore, the antagonistic effect of KCl-depolarization contractions may be an auxiliary mechanism of the curative effect.
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Affiliation(s)
- Chun-Sen Hsu
- Department of Obstetrics and Gynecology, Taipei Wan-Fang Hospital-af fi liated Taipei Medical University, Taipei, Taiwan
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Vedernikov YP, Hartke JR, de Long MA, Saade GR, Garfield RE. Sex hormone effects in non-pregnant rat and human myometrium. Eur J Obstet Gynecol Reprod Biol 2003; 108:59-66. [PMID: 12694972 DOI: 10.1016/s0301-2115(02)00415-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To study effects of sex hormones on spontaneous contractility and on the effects of depolarizing agent potassium chloride (KCl), M-cholinoceptor and prostaglandin receptor agonists on non-pregnant rat and human uterine tissues. STUDY DESIGN Uterine rings from ovariectomized rats treated with sex hormones or placebo, and uterine strips from premenopausal and postmenopausal women were equilibrated in Krebs buffer (t=37 degrees C, pH approximately 7.4) for isometric tension recordings. Spontaneous contractile activity and contractions in response to KCl, eicosanoids, and acetylcholine were compared. RESULTS In tissues from ovariectomized rats, spontaneous contractility was increased, while KCl-induced contractions were decreased. Treatment with 17beta-estradiol, but not progesterone, inhibited spontaneous contractions, but potentiated KCl evoked contractions. Treatment with 17beta-estradiol did not influence responses to prostanoids in ovariectomized rats, while treatment with both sex hormones restored decreased the responses. Spontaneous contractility and responses to KCl were less in uterine tissues from postmenopausal versus premenopausal women. Hormone replacement therapy partly restored the responses to KCl, prostanoids, and acetylcholine. CONCLUSIONS Ovarian steroids modulate spontaneous contractile activity, responses to depolarization, prostanoids and M-cholinoceptor activation in non-pregnant rat and human uterine tissues in vitro.
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Affiliation(s)
- Yuri P Vedernikov
- Department of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Texas Medical Branch, 301 University Building, Galveston, TX 77555-1062, USA.
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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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Picherit C, Dalle M, Néliat G, Lebecque P, Davicco MJ, Barlet JP, Coxam V. Genistein and daidzein modulate in vitro rat uterine contractile activity. J Steroid Biochem Mol Biol 2000; 75:201-8. [PMID: 11226836 DOI: 10.1016/s0960-0760(00)00179-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The present study investigated the effect of genistein, daidzein and estradiol on in vitro rat uterine responsiveness to oxytocin (OT) and PGF(2)alpha or luprostiol (L). In a first experiment, animals were either sham-operated (SH; n=5), or ovariectomized (OVX; n=20) and orally treated for three months with either genistein (G; n=5; 10 microg/g BW/d) or daidzein (D; n=5; 10 microg/g BW/d) or 17 alpha-ethinylestradiol (E; n=5; 23 microg/kg BW/d) or untreated (OVX; n=5). At necropsy, the basal uterine tension was lower in OVX, G and D than in SH, the highest value being measured in E. Oxytocin (10(-12); 10(-11) M) or PGF(2)alpha (10(-12); 10(-9) M) induced an increase in SH, but not in OVX, E and G. In D, only the highest doses were efficient. In a second experiment, 20 intact animals were s.c. injected with either genistein (G; n=5; 10 microg/g BW) or daidzein (D; n=5; 10 microg/g BW) or estradiol benzoate (E; n=5; 23 microg/kg BW) or vehicle (C: controls; n=5), and killed 24 h later. In C and E, OT (10(-15) to 10(-10) M) or L (10(-12) to 10(-7) M) stimulated uterine contractile activity in a dose-dependent manner until a maximal level. On the opposite, in G and D, contractile agents (except the highest luprostiol doses) did not stimulate myometrium contractions. Moreover, radioligand binding assays showed that genistein or daidzein inhibited the specific binding of [(3)H] estradiol to the calf uterus estrogen receptor (ER). Therefore, it could be postulated that both genistein and daidzein might bind to the rat uterus ER, inducing either anti-estrogenic or very weak estrogenic effects (depending on the experimental conditions) on in vitro uterine responsiveness to OT and PGF(2)alpha or luprostiol.
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Affiliation(s)
- C Picherit
- Métabolisme Minéral, Laboratoire des Maladies Métaboliques et Micronutriments, I.N.R.A. Clermont-Ferrand/Theix, 63122 Saint Genès Champanelle, France
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Engstrøm T, Bratholm P, Christensen NJ, Vilhardt H. Effect of oxytocin receptor blockade on rat myometrial responsiveness to prostaglandin f(2)(alpha). Biol Reprod 2000; 63:1443-9. [PMID: 11058550 DOI: 10.1095/biolreprod63.5.1443] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In the present study we have shown that the genetic expression of prostaglandin (PG)F(2alpha) receptor (R) and cyclooxygenase (COX)-2 increases in laboring rat myometrium. This finding was associated with a relatively weak contractile in vitro response (E:(max)) of isolated uterine strips when challenged with PGF(2alpha). Five days postpartum PGF(2alpha)-R mRNA values exceeded those during labor while COX-2 mRNA was reduced to preparturient values. Maximal contractility of isolated strips stimulated with PGF(2alpha) at this time was enhanced and E:C(50) decreased. Oxytocin treatment of estrogen-primed nonpregnant rats down-regulated uterine contractile responsiveness to PGF(2alpha), leaving mRNA values for this receptor unchanged, whereas oxytocin receptor blockade with atosiban (an oxytocin receptor antagonist) left E:(max) unaltered. In contrast, atosiban treatment of pregnant rats resulted in a 2.5-fold increase in E:(max) and a considerably reduced EC(50) during labor when compared to untreated delivering rats. The increased contractile ability was associated with a threefold increase in PGF(2alpha)-R mRNA production, indicating that the regulation by atosiban of the PGF(2alpha)-induced response is exerted at the genetic level. Based on the present data we suggest that 1) PGF(2alpha)-R stimulation may not primarily exert a contracting role in the normally delivering myometrium, and 2) the presence of the PGF(2alpha)-R system in rat myometrium may explain the apparent functional redundancy of the oxytocinergic system during the process of birth in animals lacking oxytocin or where the oxytocin receptor is blocked. In this context PGF(2alpha) receptor stimulation may, in the absence of oxytocin receptor stimulation, exert the contractile forces needed for proper propulsion of the fetus.
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Affiliation(s)
- T Engstrøm
- Department of Internal Medicine and Endocrinology, Herlev Hospital, University of Copenhagen, Denmark.
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Umscheid CA, Wu WX, Gordan P, Nathanielsz PW. Up-regulation of oxytocin receptor messenger ribonucleic acid and protein by estradiol in the cervix of ovariectomized rat. Biol Reprod 1998; 59:1131-8. [PMID: 9780319 DOI: 10.1095/biolreprod59.5.1131] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Oxytocin receptor (OTR) regulation has been extensively studied in uterine myometrium and endometrium. However, studies in the cervix are limited. The present studies utilized in situ hybridization and immunocytochemistry to localize OTR mRNA and protein distribution in cervices of nonpregnant ovariectomized (OVX) rats and examined the effect of combined and independent treatments with estradiol and progesterone on cervical OTR. Thirteen nonpregnant rats were bilaterally OVX under general anesthesia. At least 7 days later, the rats were exposed to one of four different treatments 24 h prior to necropsy: 1) estradiol (50 microg, n = 4); 2) progesterone (10 mg, n = 3); 3) both estradiol (50 microg) and progesterone (10 mg) (n = 3); 4) corn oil vehicle (n = 3). After 24-h estradiol treatment, OTR mRNA increased significantly (p < 0.05) in smooth muscle cells of the rat cervix as a result of increased copy numbers of OTR mRNA per cell as well as an increased population of OTR mRNA-positive cells. Progesterone alone had no effect on OTR mRNA expression; however, progesterone combined with estradiol significantly inhibited the up-regulation of OTR mRNA by estradiol alone. The increase of OTR mRNA in cervical epithelial cells was minimal in all situations. Intensity of cervical OTR immunostaining in both the epithelial cells and cervical smooth muscle cells was also elevated after estradiol treatment. The anti-rat OTR antiserum used for immunocytochemistry was validated by Western blot analysis. In conclusion, OTR and OTR mRNA were localized in smooth muscle cells and in epithelial cells of rat cervix. Estradiol-dependent activation of OTR gene expression and active OTR synthesis in smooth muscle cells account for the increased OTR level in rat cervix in vivo, in which progesterone acted as an antagonist of estradiol on OTR gene expression.
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Affiliation(s)
- C A Umscheid
- Laboratory for Pregnancy and Newborn Research, Department of Physiology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853-6401, USA
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