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Gimenez C, Alperin M, De Vita R. The Effect of Menopause on Vaginal Tissue Mechanics: A Brief Review. J Biomech Eng 2024; 146:060903. [PMID: 37542707 DOI: 10.1115/1.4063101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/01/2023] [Indexed: 08/07/2023]
Abstract
Often called "the change of life," menopause affects every part of a woman's body. As the sex hormones decrease, the reproductive organs experience the most remarkable changes, with the vagina becoming thinner, drier, and less elastic. Despite the important implications of these changes in genitourinary conditions, there are only a few experimental studies that focus on quantifying the effect of menopause on the mechanical properties of the vagina. These studies are mostly conducted using uniaxial tests on strips of vaginal tissues isolated from rats, rabbits, and sheep and, in only a few cases, from humans. The purpose of this article is to present a systematic review of experimental protocols, methods, and results that are currently published on how menopause alters the mechanical behavior of the vagina. This review will enable new investigators in the biomechanics field to identify important gaps and frame research questions that inform the design of new treatment options for menopausal symptoms.
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Affiliation(s)
- Clara Gimenez
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
- Virginia Tech
| | - Marianna Alperin
- Division of Urogynecology and Pelvic Reconstructive Surgery, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Diego, Sanford Consortium for Regenerative Medicine, La Jolla, CA 92097
| | - Raffaella De Vita
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
- Virginia Tech Services
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Clark-Patterson GL, Buchanan LM, Ogola BO, Florian-Rodriguez M, Lindsey SH, De Vita R, Miller KS. Smooth muscle contribution to vaginal viscoelastic response. J Mech Behav Biomed Mater 2023; 140:105702. [PMID: 36764168 DOI: 10.1016/j.jmbbm.2023.105702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/22/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
Smooth muscle cells contribute to the mechanical function of various soft tissues, however, their contribution to the viscoelastic response when subjected to multiaxial loading remains unknown. The vagina is a fibromuscular viscoelastic organ that is exposed to prolonged and increased pressures with daily activities and physiologic processes such as vaginal birth. The vagina changes in geometry over time under prolonged pressure, known as creep. Vaginal smooth muscle cells may contribute to creep. This may be critical for the function of vaginal and other soft tissues that experience fluctuations in their biomechanical environment. Therefore, the objective of this study was to develop methods to evaluate the contribution of smooth muscle to vaginal creep under multiaxial loading using extension - inflation tests. The vaginas from wildtype mice (C57BL/6 × 129SvEv; 3-6 months; n = 10) were stimulated with various concentrations of potassium chloride then subjected to the measured in vivo pressure (7 mmHg) for 100 s. In a different cohort of mice (n = 5), the vagina was stimulated with a single concentration of potassium chloride then subjected to 5 and 15 mmHg. A laser micrometer measured vaginal outer diameter in real-time. Immunofluorescence evaluated the expression of alpha-smooth muscle actin and myosin heavy chain in the vaginal muscularis (n = 6). When smooth muscle contraction was activated, vaginal creep behavior increased compared to the relaxed state. However, increased pressure decreased the active creep response. This study demonstrated that extension - inflation protocols can be used to evaluate smooth muscle contribution to the viscoelastic response of tubular soft tissues.
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Affiliation(s)
| | - Lily M Buchanan
- University of Texas at Dallas, Department of Bioengineering, 800 W. Campbell Road, Richardson, TX, 75080, USA.
| | - Benard O Ogola
- Augusta University, Vascular Biology Center, Medical College of Georgia at Augusta University, 1460 Laney Walker Blvd, Augusta, GA, 30912, USA.
| | - Maria Florian-Rodriguez
- University of Texas Southwestern Medical Center, Department of Obstetrics and Gynecology, Division of Female Pelvic Medicine and Reconstructive Surgery and Cecil H and Ida Green Center for Reproductive Biological Sciences, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9032, USA.
| | - Sarah H Lindsey
- Tulane University School of Medicine, Department of Pharmacology, 1430 Tulane Ave, New Orleans, LA, 70112, USA.
| | - Raffaella De Vita
- Virginia Tech,Department of Biomedical Engineering and Mechanics, 330 A Kelly Hall, 325 Stanger St, Blacksburg, VA, 24061, USA.
| | - Kristin S Miller
- Tulane University, Department of Biomedical Engineering, 6823 St Charles Ave, New Orleans, LA, 70118, USA; University of Texas at Dallas, Department of Bioengineering, 800 W. Campbell Road, Richardson, TX, 75080, USA.
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Huntington AJ, Udayasuryan B, Du P, Verbridge SS, Abramowitch SD, Vita RD. Smooth Muscle Organization and Nerves in the Rat Vagina: A First Look Using Tissue Clearing and Immunolabeling. Ann Biomed Eng 2022; 50:440-451. [PMID: 35182248 DOI: 10.1007/s10439-022-02928-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/06/2022] [Indexed: 12/28/2022]
Abstract
Smooth muscle fibers within the vagina, as well as the nerve fibers that contribute to their control mechanisms, are important for the maintenance and alteration of vaginal length and tone. Vaginal smooth muscle (VaSM) is typically described as being arranged into two distinct concentric layers: an inner circular muscular layer and an outer longitudinal muscular layer. However, the distribution of VaSM oriented in the longitudinal direction (LD) and circumferential direction (CD) has never been quantified. In this study, tissue clearing and immunohistochemistry were performed so that the VaSM, and surrounding nerves, within whole rat vaginas ([Formula: see text]) could be imaged without tissue sectioning, preserving the three-dimensional architecture of the organs. Using these methods, the vagina was viewed through the full thickness of the muscularis layer, from the distal to the proximal regions. The VaSM orientation in the proximal and distal regions and the VaSM content along the LD and CD were quantified. Additionally, a qualitative assessment of vaginal nerves was performed. When compared using a permuted version of the Watson [Formula: see text] test, the orientation of VaSM in the proximal and distal regions were found to be significantly different in 4 of the 6 imaged rat vaginas ([Formula: see text]). While the distal vagina contained a similar amount of VaSM oriented within [Formula: see text] of the LD and within [Formula: see text] of the CD, the proximal vagina contained significantly more VaSM oriented towards the LD than towards the CD. Nerve fibers were found to be wavy, running both parallel and perpendicular to vascular and non-vascular smooth muscle within the vagina. Micro-structural analyses, like the one conducted here, are necessary to understand the physiological function and pathological changes of the vagina.
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Affiliation(s)
- Alyssa J Huntington
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, 330A Kelly Hall, 325 Stanger Street, Blacksburg, 24061, VA, USA
| | - Barath Udayasuryan
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 330 Kelly Hall, 325 Stanger Street, Blacksburg, 24061, VA, USA
| | - Pang Du
- Department of Statistics, Virginia Tech, 417A Hutcheson Hall, 250 Drillfield Drive, Blacksburg, 24061, VA, USA
| | - Scott S Verbridge
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 330 Kelly Hall, 325 Stanger Street, Blacksburg, 24061, VA, USA
| | - Steven D Abramowitch
- Translational Biomechanics Lab, Department of Bioengineering, University of Pittsburgh, Benedum Hall, 3700 O'Hara Street, Pittsburgh, 15213, PA, USA
| | - Raffaella De Vita
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, 330A Kelly Hall, 325 Stanger Street, Blacksburg, 24061, VA, USA.
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Huntington A, Abramowitch SD, Moalli PA, De Vita R. Strains induced in the vagina by smooth muscle contractions. Acta Biomater 2021; 129:178-187. [PMID: 34033971 DOI: 10.1016/j.actbio.2021.05.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 12/26/2022]
Abstract
The ability of the vagina to contract gives rise to a set of active mechanical properties that contribute to the complex function of this organ in-vivo. Regional differences in the morphology of the vagina have been long recognized, but the large heterogeneous deformations that the vagina experiences during contractions have never been quantified. Furthermore, there is no consensus regarding differences in contractility along the two primary anatomical directions of the vagina: the longitudinal direction (LD) and the circumferential direction (CD). In this study, square vaginal specimens from healthy virgin rats (n=15) were subjected to isometric planar biaxial tests at four equi-biaxial stretches of 1.0, 1.1, 1.2, and 1.3. Contractions were induced at each stretch by a high concentration potassium solution. The digital image correlation method was used to perform full-field strain measurements during contractions. The vagina was found to undergo significantly higher compressive strains, tensile strains, and contractile forces along the LD than along the CD during contractions. Specifically, when computed over all the applied equi-biaxial stretches, mean (± std. dev.) absolute maximum compressive strains were -(13.43 ± 1.56)% along the LD and -(3.19 ± 0.25)% along the CD, mean absolute maximum tensile strains were (10.92 ± 1.73)% along the LD and (3.62 ± 0.57)% along the CD, and mean maximum contractile forces were 6.24 ± 0.55 mN along the LD and 3.35 ± 0.56 mN along the CD. Moreover, the vaginal tissue appeared to undergo compression in the proximal region and tension in the distal region while kept at constant equi-biaxial stretches. The active mechanical properties of the healthy vagina need to be fully investigated so that detrimental alterations in vaginal contractility, such as those caused by pelvic floor disorders and current treatment strategies, can be prevented. STATEMENT OF SIGNIFICANCE: Contractile forces of the vagina have been measured by several investigators using uniaxial tensile testing methods. Unlike previous studies, in this study planar-biaxial tests of vaginal specimens were performed while the full-field strains of the vagina, as induced by smooth muscle contraction, were measured. The vagina was found to generate significantly larger contractile strains and forces in the longitudinal direction than in the circumferential direction. Knowledge of the contractile mechanics of the healthy vagina is essential to understand the detrimental effects that pelvic organ prolapse and the use of surgical meshes have on the functionality of smooth muscle in the vagina.
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Affiliation(s)
- Alyssa Huntington
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Steven D Abramowitch
- Translational Biomechanics Lab, Department of Bioengineering, University of Pittsburgh, Benedum Hall, 3700 O'Hara Street, Pittsburgh, PA, 15213, USA
| | - Pamela A Moalli
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Magee-Womens Research Institute, 204 Craft Ave, Pittsburgh, PA, 15213, USA
| | - Raffaella De Vita
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, 24061, USA.
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Mori da Cunha MGMC, Mackova K, Hympanova LH, Bortolini MAT, Deprest J. Animal models for pelvic organ prolapse: systematic review. Int Urogynecol J 2021; 32:1331-1344. [PMID: 33484287 PMCID: PMC8203535 DOI: 10.1007/s00192-020-04638-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/02/2020] [Indexed: 12/27/2022]
Abstract
INTRODUCTION AND HYPOTHESIS We aimed to summarize the knowledge on the pathogenesis of pelvic organ prolapse (POP) generated in animal models. METHODS We searched MEDLINE, Embase, Cochrane and the Web of Science to establish what animal models are used in the study of suggested risk factors for the development of POP, including pregnancy, labor, delivery, parity, aging and menopause. Lack of methodologic uniformity precluded meta-analysis; hence, results are presented as a narrative review. RESULTS A total of 7426 studies were identified, of which 51 were included in the analysis. Pregnancy has a measurable and consistent effect across species. In rats, simulated vaginal delivery induces structural changes in the pelvic floor, without complete recovery of the vaginal muscular layer and its microvasculature, though it does not induce POP. In sheep, first vaginal delivery has a measurable effect on vaginal compliance; measured effects of additional deliveries are inconsistent. Squirrel monkeys can develop POP. Denervation of their levator ani muscle facilitates this process in animals that delivered vaginally. The models used do not develop spontaneous menopause, so it is induced by ovariectomy. Effects of menopause depend on the age at ovariectomy and the interval to measurement. In several species menopause is associated with an increase in collagen content in the longer term. In rodents there were no measurable effects of age apart of elastin changes. We found no usable data for other species. CONCLUSION In several species there are measurable effects of pregnancy, delivery and iatrogenic menopause. Squirrel monkeys can develop spontaneous prolapse.
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Affiliation(s)
- Marina Gabriela M C Mori da Cunha
- Centre for Surgical Technologies, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- Department of Development and Regeneration, Woman and Child, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Katerina Mackova
- Centre for Surgical Technologies, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- Department of Development and Regeneration, Woman and Child, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
- Institute for the Care of Mother and Child, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Lucie Hajkova Hympanova
- Institute for the Care of Mother and Child, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Maria Augusta T Bortolini
- Department of Gynecology, Sector of Urogynecology, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Jan Deprest
- Centre for Surgical Technologies, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.
- Department of Development and Regeneration, Woman and Child, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.
- Pelvic Floor Unit, University Hospitals, KU Leuven, Leuven, Belgium.
- Department of Development and Regeneration, Center of Surgical Technologies UZ Herestraat, Herestraat49, B3000, Leuven, Belgium.
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Huntington A, Donaldson K, De Vita R. Contractile Properties of Vaginal Tissue. J Biomech Eng 2020; 142:080801. [PMID: 32203570 PMCID: PMC10854261 DOI: 10.1115/1.4046712] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/26/2020] [Indexed: 01/11/2024]
Abstract
The vagina is an important organ of the female reproductive system that has been largely understudied in the field of biomechanics. In recent years, some research has been conducted to evaluate the mechanical properties of the vagina, but much has focused on characterizing the passive mechanical properties. Because vaginal contractions play a central role in sexual function, childbirth, and development and treatment of pelvic floor disorders, the active mechanical properties of the vagina must be also quantified. This review surveys and summarizes published experimental studies on the active properties of the vagina including the differences in such properties determined by anatomic regions and orientations, neural pathways, life events such as pregnancy and menopause, pelvic floor disorders such as prolapse, and surgical mesh treatment. Conflicting experimental findings are presented, illustrating the need for further research on the active properties of the vagina. However, consensus currently exists regarding the negative impact of surgical mesh on vaginal contractility. This review also identifies knowledge gaps and future research opportunities, thus proving a firm foundation for novice and experienced researchers in this emerging area of biomechanics and encouraging more activity on women's sexual and reproductive health research.
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Affiliation(s)
- Alyssa Huntington
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
| | - Kandace Donaldson
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
| | - Raffaella De Vita
- STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
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Zhang N, Qin X, Zhang J, Zhang Z, Li Y, Xie Y, Kong D, Du R, Huang X, Xu Y. Bone Marrow Mesenchymal Stem Cells Accelerate the Morphological and Functional Recovery of Neovaginas. Artif Organs 2018; 42:1206-1215. [DOI: 10.1111/aor.13297] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/18/2018] [Accepted: 05/24/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Ning Zhang
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Xijing Qin
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Jingkun Zhang
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Zhiqiang Zhang
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Yanan Li
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Yanling Xie
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Desheng Kong
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Runxuan Du
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Xianghua Huang
- Department of Obstetrics and Gynecology; The Second Hospital of Hebei Medical University
| | - Yanfang Xu
- Department of Pharmacology; Hebei Medical University; Shijiazhuang China
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Ruiz-Zapata AM, Feola AJ, Heesakkers J, de Graaf P, Blaganje M, Sievert KD. Biomechanical Properties of the Pelvic Floor and its Relation to Pelvic Floor Disorders. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.eursup.2017.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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First delivery and ovariectomy affect biomechanical and structural properties of the vagina in the ovine model. Int Urogynecol J 2018; 30:455-464. [DOI: 10.1007/s00192-017-3535-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 11/28/2017] [Indexed: 01/08/2023]
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van Helden DF, Kamiya A, Kelsey S, Laver DR, Jobling P, Mitsui R, Hashitani H. Nerve-induced responses of mouse vaginal smooth muscle. Pflugers Arch 2017; 469:1373-1385. [DOI: 10.1007/s00424-017-1995-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 03/30/2017] [Accepted: 05/10/2017] [Indexed: 12/23/2022]
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Zhang JK, Du RX, Zhang L, Li YN, Zhang ML, Zhao S, Huang XH, Xu YF. A new material for tissue engineered vagina reconstruction: Acellular porcine vagina matrix. J Biomed Mater Res A 2017; 105:1949-1959. [PMID: 28294563 DOI: 10.1002/jbm.a.36066] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 02/25/2017] [Accepted: 03/07/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Jing-Kun Zhang
- Department of Obstetrics and Gynecology; the Second Hospital of Hebei Medical University; Shijiazhuang Hebei 050000 China
| | - Run-Xuan Du
- Department of Obstetrics and Gynecology; the Second Hospital of Hebei Medical University; Shijiazhuang Hebei 050000 China
| | - Lin Zhang
- Department of Obstetrics and Gynecology; the Second Hospital of Hebei Medical University; Shijiazhuang Hebei 050000 China
| | - Ya-Nan Li
- Department of Obstetrics and Gynecology; the Second Hospital of Hebei Medical University; Shijiazhuang Hebei 050000 China
| | - Ming-Le Zhang
- Department of Obstetrics and Gynecology; the Second Hospital of Hebei Medical University; Shijiazhuang Hebei 050000 China
| | - Shuo Zhao
- School of Mechanical Engineering; Hebei University of Science and Technology; Shijiazhuang Hebei 050018 China
| | - Xiang-Hua Huang
- Department of Obstetrics and Gynecology; the Second Hospital of Hebei Medical University; Shijiazhuang Hebei 050000 China
| | - Yan-Fang Xu
- Department of Pharmacology; Hebei Medical University; Shijiazhuang Hebei 050000 China
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Ishii A, Ogawa B, Koyama T, Nakanishi Y, Sasaki M. Influence of the estrus cycle on the evaluation of a vaginal irritation study in intact and ovariectomized rats. J Toxicol Pathol 2017; 30:161-168. [PMID: 28458454 PMCID: PMC5406595 DOI: 10.1293/tox.2016-0059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/20/2016] [Indexed: 11/29/2022] Open
Abstract
When conducting vaginal irritation studies, ovariectomized rats or rabbits are typically used according to practical reports. In the present study, we evaluated the influence of the estrus cycle in a vaginal irritation study using intact rats and ovariectomized rats, which exhibit a late diestrus-like condition, to determine whether intact rats can be useful for evaluating vaginal irritancy. Rats were divided into 4 groups: proestrus, estrus, and metestrus or diestrus in intact rats and ovariectomized rats. All the rats in each group were treated with a vehicle or sodium dodecyl sulfate, as the irritant, in single-dose and 4-day repeat-dose vaginal irritation studies. Each rat’s vagina was examined histopathologically, and the irritation score was calculated using a semiquantitative scoring system. In the single-dose study, the irritation scores for the proestrus or ovariectomized groups treated with sodium dodecyl sulfate were higher than those of the estrus group or metestrus or diestrus group. In the 4-day repeat-dose study, a significant histopathological difference was not found among the intact rats (proestrus, estrus, and metestrus or diestrus groups), and the irritation score range of the intact rats was similar to that of the ovariectomized rats, though the mean score of the intact rats was slightly lower than that of the ovariectomized rats. These results suggest that intact rats might be well suited for 4-day vaginal irritation studies and useful for evaluating vaginal irritancy using not only the mean score, but also individual irritation score ranges, whereas the estrus cycle would need to be identified in single-dose vaginal irritation studies.
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Affiliation(s)
- Aiko Ishii
- Drug Safety, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshino-cho, Kita-ku, Saitama-shi, Saitama 331-9530, Japan
| | - Bunichiro Ogawa
- Drug Safety, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshino-cho, Kita-ku, Saitama-shi, Saitama 331-9530, Japan
| | - Tomoko Koyama
- Drug Safety, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshino-cho, Kita-ku, Saitama-shi, Saitama 331-9530, Japan
| | - Yutaka Nakanishi
- Drug Safety, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshino-cho, Kita-ku, Saitama-shi, Saitama 331-9530, Japan
| | - Minoru Sasaki
- Drug Safety, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshino-cho, Kita-ku, Saitama-shi, Saitama 331-9530, Japan
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13
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Basha ME, Chang S, Burrows LJ, Lassmann J, Wein AJ, Moreland RS, Chacko S. Effect of estrogen on molecular and functional characteristics of the rodent vaginal muscularis. J Sex Med 2013; 10:1219-30. [PMID: 23438289 DOI: 10.1111/jsm.12088] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Vaginal atrophy is a consequence of menopause; however, little is known concerning the effect of a decrease in systemic estrogen on vaginal smooth muscle structure and function. As the incidence of pelvic floor disorders increases with age, it is important to determine if estrogen regulates the molecular composition and contractility of the vaginal muscularis. AIM The goal of this study was to determine the effect of estrogen on molecular and functional characteristics of the vaginal muscularis utilizing a rodent model of surgical menopause. METHODS Three- to 4-month old Sprague-Dawley rats underwent sham laparotomy (Sham, N = 18) or ovariectomy (Ovx, N = 39). Two weeks following surgery, animals received a subcutaneous osmotic pump containing vehicle (Sham, Ovx) or 17β-estradiol (Ovx). Animals were euthanized 1 week later, and the proximal vagina was collected for analysis of contractile protein expression and in vitro studies of contractility. Measurements were analyzed using a one-way analysis of variance followed by Tukey's post hoc analysis (α = 0.05). MAIN OUTCOME MEASURES Protein and mRNA transcript expression levels of contractile proteins, in vitro measurements of vaginal contractility. RESULTS Ovariectomy decreased the expression of carboxyl-terminal myosin heavy chain isoform (SM1) and h-caldesmon and reduced the amplitude of contraction of the vaginal muscularis in response to KCl. Estradiol replacement reversed these changes. No differences were detected in the % vaginal muscularis, mRNA transcript expression of amino-terminal MHC isoforms, l-caldesmon expression, and maximal velocity of shortening. CONCLUSION Systemic estrogen replacement restores functional and molecular characteristics of the vaginal muscularis of ovariectomized rats. Our results indicate that menopause is associated with changes in the vaginal muscularis, which may contribute to the increased incidence of pelvic floor disorders with age.
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Affiliation(s)
- Maureen E Basha
- Department of Human Science, School of Nursing and Health Studies, Georgetown University, Washington, DC 20057, USA.
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14
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Skoczylas LC, Jallah Z, Sugino Y, Stein SE, Feola A, Yoshimura N, Moalli P. Regional differences in rat vaginal smooth muscle contractility and morphology. Reprod Sci 2013; 20:382-90. [PMID: 23298869 DOI: 10.1177/1933719112472733] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The objective of this study was to define the regional differences in rat vaginal smooth muscle contractility and morphology. We evaluated circumferential segments from the proximal, middle, and distal rat vagina (n = 21) in vitro. Contractile responses to carbachol, phenylephrine, potassium chloride, and electrical field stimulation (EFS) were measured. Immunohistochemical analyses were also performed. The dose-response curves for carbachol- and phenylephrine-dependent contractions were different in the distal (P = .05, P = .04) compared to the proximal/middle regions. Adjusted for region-dependent changes in contractility, the distal vagina generated lower force in response to carbachol and higher force in response to phenylephrine. There was less force with increasing EFS frequency in the distal (P = .03), compared to the proximal/middle regions. Cholinergic versus adrenergic nerves were more frequent in the proximal region (P = .03). In summary, the results indicate that functional and morphological differences in smooth muscle and nerve fibers of the distal versus proximal/middle regions of the vagina exist.
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Affiliation(s)
- Laura C Skoczylas
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Magee-Womens Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Basha M, Labelle EF, Northington GM, Wang T, Wein AJ, Chacko S. Functional significance of muscarinic receptor expression within the proximal and distal rat vagina. Am J Physiol Regul Integr Comp Physiol 2009; 297:R1486-93. [PMID: 19741053 DOI: 10.1152/ajpregu.90516.2008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Information regarding the role of cholinergic nerves in mediating vaginal smooth muscle contraction is sparse, and in vitro studies of the effects of muscarinic agonists on vaginal smooth muscle are discrepant. The goal of this study was to determine the expression of muscarinic receptors in the vaginal wall of the rat. In addition, we sought to determine the effect of the muscarinic receptor agonist carbachol on contractility and inositol phosphate production of the proximal and distal rat vaginal muscularis. RT-PCR analysis indicated that both M(2) and M(3) receptor transcripts were expressed within the proximal and distal rat vagina. Carbachol dose-dependently (10(-7)-10(-4) M) contracted the rat vaginal muscularis with a greater maximal contractile response in the proximal vagina (P < 0.01) compared with the distal vagina. The contractile responses of the rat vaginal muscularis to carbachol were dose dependently inhibited by the M(3) antagonist para-fluoro-hexahydrosiladefenidol, and a pK(B) of 7.78 and 7.95 was calculated for the proximal and distal vagina, respectively. Inositol phosphate production was significantly increased in both regions of the vagina following 20-min exposure to 50 muM carbachol with higher levels detected in the proximal vagina compared with the distal (P < 0.05). Preliminary experiments indicated the presence of M(2) and M(3) receptors in the human vaginal muscularis as well as contraction of human vaginal muscularis to carbachol, indicating that our animal studies are relevant to human tissue. Our results provide strong evidence for the functional significance of M(3) receptor expression in the vaginal muscularis.
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Affiliation(s)
- Maureen Basha
- Department of Pharmacology and Physiology, Drexel University College of Medicine; Philadelphia, USA
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Cushman T, Kim N, Hoyt R, Traish AM. Estradiol restores diabetes-induced reductions in sex steroid receptor expression and distribution in the vagina of db/db mouse model. J Steroid Biochem Mol Biol 2009; 114:186-94. [PMID: 19429450 DOI: 10.1016/j.jsbmb.2009.01.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 01/28/2009] [Accepted: 01/29/2009] [Indexed: 12/16/2022]
Abstract
Sex steroid hormones and receptors play an important role in maintaining vaginal physiology. Disruptions in steroid receptor signaling adversely impact vaginal function. Limited studies are available investigating the effects of diabetic complications on steroid receptor expression and distribution in the vagina. The goals of this study were to investigate type 2 diabetes-induced changes in expression, localization and distribution of estrogen (ER), progesterone (PR) and androgen receptors (AR) in the vagina and to determine if estradiol treatment ameliorates these changes. Eight-week-old female diabetic (db/db) mice (strain BKS.Cg-m+/+ Lepr(db)/J) were divided into two subgroups: untreated diabetic and diabetic animals treated with pellets containing estradiol. Control normoglycemic littermates were subcutaneously implanted with pellets devoid of estradiol. At 16 weeks of age, animals were sacrificed, vaginal tissues excised and analyzed by Western blot and immunohistochemical methods. Diabetes produced marked reductions in protein expression of ER, PR, and AR. Diabetes also resulted in marked differences in the distribution, staining intensity and proportion of immunoreactive cells containing these steroid receptors in the epithelium, lamina propria and muscularis. Treatment of diabetic animals with estradiol restored receptor protein expression and distribution similar to those levels observed in control animals. This study demonstrates that type 2 diabetes markedly reduces steroid receptor protein expression and distribution in the vagina. Estradiol treatment of diabetic animals ameliorates these diabetes-induced changes.
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Affiliation(s)
- Tulay Cushman
- Department of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA 02118, USA
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Musicki B, Liu T, Lagoda GA, Bivalacqua TJ, Strong TD, Burnett AL. Endothelial nitric oxide synthase regulation in female genital tract structures. J Sex Med 2008; 6 Suppl 3:247-53. [PMID: 19138376 DOI: 10.1111/j.1743-6109.2008.01122.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Female sexual arousal disorder (FSAD) is a major component of female sexual dysfunctions, affecting 25-70% of women. The mechanisms of FSAD are poorly understood. Estrogen contributes to the control of genital blood flow during the sexual response. Vascular effects of estrogen are mostly attributed to its regulation of endothelial nitric oxide (NO) production. However, the role of endothelial NO synthase (eNOS) and the mechanisms that regulate eNOS in female genital tract structures are largely unknown. AIM To review available evidence of the mechanisms of eNOS regulation in female genital tract structures. METHODS This article reviews the literature that relates to the role of NO and eNOS in female sexual arousal and its modulation by estrogen. MAIN OUTCOME MEASURES Association between female sexual arousal, NO, and eNOS. RESULTS The NO/cyclic guanosine monophosphate pathway is believed to have a primary role in the regulation of clitoral and vaginal blood flow, and smooth muscle relaxation during sexual arousal. Estrogen is critical for maintaining vaginal and clitoral blood flow and vaginal transudate production. Estrogen regulates eNOS by genomic mechanisms, involving augmented mRNA transcription and protein synthesis, and by non-genomic mechanisms, which occur without alterations in gene expression. However, limited studies have evaluated the physiological role of endothelial NO and the molecular mechanisms of eNOS regulation in the female genital tract. CONCLUSIONS The effects of estrogen on increasing genital blood flow and smooth muscle relaxation have been attributed mostly to regulation of eNOS. However, the exact mechanisms of eNOS regulation in female genital tract structures and the molecular basis for the eNOS defect with aging and vascular diseases warrant further investigation.
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Affiliation(s)
- Biljana Musicki
- Department of Urology, The Johns Hopkins University, Baltimore, MD 21287, USA.
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Goldstein I. Sexual dysfunction in women: what can urologists contribute? Curr Urol Rep 2008; 9:475-82. [PMID: 18947512 DOI: 10.1007/s11934-008-0081-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Urologists have led the basic science and clinical research of organic-based issues in male sexual dysfunction. Concerning scientific, evidence-based, biologic-focused information, the field of sexual dysfunction in women is relatively new compared with sexual dysfunction in men. Basic science, epidemiology, physiology, pathophysiology, diagnosis, and treatment data on women's sexual health issues are now more regularly published than ever before, with the urologic community once again leading the way. This article reviews some pioneering, resourceful, creative, and novel contributions that urologists have made to enhance the understanding of sexual dysfunction in women. As is obvious in infertility treatment, sexual medicine health care requires biologic and psychologic attention to both members of the couple. The goal of all sexual medicine health care providers is to provide the best health care delivery to women and men with sexual health concerns.
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Affiliation(s)
- Irwin Goldstein
- San Diego Sexual Medicine, Alvarado Hospital, San Diego, CA 92120, USA.
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Goldstein I. EDITORIAL: Sexual Dysfunction: Looking Beyond the Obvious. J Sex Med 2008; 5:1-3. [DOI: 10.1111/j.1743-6109.2007.00677.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Erol B, Sanli O, Korkmaz D, Seyhan A, Akman T, Kadioglu A. A Cross-Sectional Study of Female Sexual Function and Dysfunction During Pregnancy. J Sex Med 2007; 4:1381-7. [PMID: 17651387 DOI: 10.1111/j.1743-6109.2007.00559.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Although women may undergo changes in sexual function during pregnancy, there are limited studies correlating possible sexual function changes to androgen blood levels during the pregnancy. AIM To search for a possible correlation, we performed a cross-sectional observational study to assess sexual function scores and androgen blood levels of women during pregnancy. MATERIALS AND METHODS A total of 589 healthy pregnant women were recruited to the present cross-sectional study. Of these patients, 116 (19.6%), 220 (37.3%), and 253 (42.9%) were in their first, second, and third trimesters, respectively. They were evaluated with a detailed medical and sexual history, including IFSF questionnaire. In addition, maternal serum androgen levels (testosterone, dehydroepiandrosterone sulphate, free testosterone) were determined in each trimester during regular follow-ups. MAIN OUTCOME MEASURES Assessment of Index of Female Sexual Function (IFSF) domains and serum androgen levels in each trimester. RESULTS The mean age of the three groups were similar (P > 0.05). Overall, total IFSF scores of women in the first and second trimesters were 21.4 +/- 10.1 and 22.3 +/- 10, respectively, while it was 15.9 +/- 12.3 during the third trimester (P < 0.05). The most common sexual dysfunction symptom was diminished clitoral sensation, observed in 94.2% of the patients, followed by lack of libido in 92.6% and orgasmic disorder in 81%. No correlation was detected between total IFSF score and serum androgen levels. CONCLUSION In this cross-sectional study, we noted lower sexual function scores in women in the third trimester of their pregnancies compared with those in their first two trimesters of pregnancy. These lower sexual function scores in the third trimester were not associated with lower androgen levels. We plan to perform a future prospective study to better assess both the change in sexual function and also its possible relation to androgen levels in pregnant women.
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Affiliation(s)
- Bulent Erol
- Department of Urology, Section of Andrology, Istanbul Faculty of Medicine, University of Istanbul, Istanbul, Turkey.
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Pauls R, Mutema G, Segal J, Silva WA, Kleeman S, Dryfhout V, Karram M. ORIGINAL RESEARCH—BASIC SCIENCE: A Prospective Study Examining the Anatomic Distribution of Nerve Density in the Human Vagina. J Sex Med 2006; 3:979-987. [PMID: 17100930 DOI: 10.1111/j.1743-6109.2006.00325.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Women possess sufficient vaginal innervation such that tactile stimulation of the vagina can lead to orgasm. However, there are few anatomic studies that have characterized the distribution of nerves throughout the human vagina. AIM The aim of this prospective study was to better characterize the anatomic distribution of nerves in the adult human vagina. A secondary aim was to assess whether vaginal innervation correlates with the subject's demographic information and sexual function. METHODS Full-thickness biopsies of anterior and posterior vagina (proximal and distal), cuff, and cervix were taken during surgery in a standardized manner. Specimens were prepared with hematoxylin and eosin, and S100 protein immunoperoxidase. The total number of nerves in each specimen was quantified. Enrolled patients completed a validated sexual function questionnaire (Female Sexual Function Index, FSFI) preoperatively. MAIN OUTCOME MEASURES A description of vaginal innervation by location and an assessment of vaginal innervation in association with the subject's demographic information and sexual function. RESULTS Twenty-one patients completed this study, yielding 110 biopsy specimens. Vaginal innervation was somewhat regular, with no site consistently demonstrating the highest nerve density. Nerves were located throughout the vagina, including apex and cervix. No significant differences were noted in vaginal innervation based on various demographic factors, including age, vaginal maturation index, stage of prolapse, number of vaginal deliveries, or previous hysterectomy. There were no correlations between vaginal nerve quantity and FSFI domain and overall scores. Fifty-seven percent of the subjects had female sexual dysfunction; when compared to those without dysfunction, there were no significant differences in total or site-specific nerves. CONCLUSIONS In a prospective study, vaginal nerves were located regularly throughout the anterior and posterior vagina, proximally and distally, including apex and cervix. There was no vaginal location with increased nerve density. Vaginal innervation was not associated with demographic information or sexual function.
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Affiliation(s)
- Rachel Pauls
- Division of Urogynecology and Reconstructive Pelvic Surgery, Good Samaritan Hospital, Cincinnati, OH.
| | - George Mutema
- Department of Pathology, Good Samaritan Hospital, Cincinnati, OH
| | - Jeffrey Segal
- Saint Barnabas Medical Center-Center for Urogynecology, Livingston, NJ
| | - W Andre Silva
- Pacific Northwest Urogynecology-Urogynecology, Federal Way, WA
| | - Steven Kleeman
- Division of Urogynecology and Reconstructive Pelvic Surgery, Good Samaritan Hospital, Cincinnati, OH
| | - Vicki Dryfhout
- Hatton Institute for Research and Education, Good Samaritan Hospital, Cincinnati, OH, USA
| | - Mickey Karram
- Division of Urogynecology and Reconstructive Pelvic Surgery, Good Samaritan Hospital, Cincinnati, OH
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