Katrina M Knight1, Pamela A Moalli1,2, Alexis Nolfi2, Stacy Palcsey2, William R Barone1, Steven D Abramowitch3,4,5. 1. Department of Bioengineering, Musculoskeletal Research Center, University of Pittsburgh, Pittsburgh, PA, USA. 2. Magee-Womens Research Institute, Department of Obstetrics and Gynecology, University of Pittsburgh, Pittsburgh, PA, USA. 3. Department of Bioengineering, Musculoskeletal Research Center, University of Pittsburgh, Pittsburgh, PA, USA. sdast9@pitt.edu. 4. Magee-Womens Research Institute, Department of Obstetrics and Gynecology, University of Pittsburgh, Pittsburgh, PA, USA. sdast9@pitt.edu. 5. Musculoskeletal Research Center, 405 Center for Bioengineering, 300 Technology Drive, Pittsburgh, PA, 15219, USA. sdast9@pitt.edu.
Abstract
INTRODUCTION AND HYPOTHESIS: Parity is the leading risk factor for the development of pelvic organ prolapse. To assess the impact of pregnancy and delivery on vaginal tissue, researchers commonly use nonhuman primate (NHP) and rodent models. The purpose of this study was to evaluate the ewe as an alternative model by investigating the impact of parity on the ewe vaginal mechanical properties and collagen structure. METHODS: Mechanical properties of 15 nulliparous and parous ewe vaginas were determined via uniaxial tensile tests. Collagen content was determined by hydroxyproline assay and collagen fiber thickness was analyzed using picrosirius red staining. Outcome measures were compared using Independent samples t or Mann-Whitney U tests. ANOVA (Gabriel's pairwise post-hoc test) or the Welch Alternative for the F-ratio (Games Howell post-hoc test) was used to compare data with previously published NHP and rodent data. RESULTS: Vaginal tissue from the nulliparous ewe had a higher tangent modulus and tensile strength compared with the parous ewe (p < 0.025). The parous ewe vagina elongated 42 % more than the nulliparous ewe vagina (p = 0.015). No significant differences were observed in collagen structure among ewe vaginas. The tangent modulus of the nulliparous ewe vagina was not different from that of the NHP or rodent (p = 0.290). Additionally, the tangent moduli of the parous ewe and NHP vaginas did not differ (p = 0.773). CONCLUSIONS: Parity has a negative impact on the mechanical properties of the ewe vagina, as also observed in the NHP. The ewe may serve as an alternative model for studying parity and ultimately prolapse development.
INTRODUCTION AND HYPOTHESIS: Parity is the leading risk factor for the development of pelvic organ prolapse. To assess the impact of pregnancy and delivery on vaginal tissue, researchers commonly use nonhuman primate (NHP) and rodent models. The purpose of this study was to evaluate the ewe as an alternative model by investigating the impact of parity on the ewe vaginal mechanical properties and collagen structure. METHODS: Mechanical properties of 15 nulliparous and parous ewe vaginas were determined via uniaxial tensile tests. Collagen content was determined by hydroxyproline assay and collagen fiber thickness was analyzed using picrosirius red staining. Outcome measures were compared using Independent samples t or Mann-Whitney U tests. ANOVA (Gabriel's pairwise post-hoc test) or the Welch Alternative for the F-ratio (Games Howell post-hoc test) was used to compare data with previously published NHP and rodent data. RESULTS: Vaginal tissue from the nulliparous ewe had a higher tangent modulus and tensile strength compared with the parous ewe (p < 0.025). The parous ewe vagina elongated 42 % more than the nulliparous ewe vagina (p = 0.015). No significant differences were observed in collagen structure among ewe vaginas. The tangent modulus of the nulliparous ewe vagina was not different from that of the NHP or rodent (p = 0.290). Additionally, the tangent moduli of the parous ewe and NHP vaginas did not differ (p = 0.773). CONCLUSIONS: Parity has a negative impact on the mechanical properties of the ewe vagina, as also observed in the NHP. The ewe may serve as an alternative model for studying parity and ultimately prolapse development.
Authors: R C Bump; A Mattiasson; K Bø; L P Brubaker; J O DeLancey; P Klarskov; B L Shull; A R Smith Journal: Am J Obstet Gynecol Date: 1996-07 Impact factor: 8.661
Authors: Jennifer M Wu; Catherine A Matthews; Mitchell M Conover; Virginia Pate; Michele Jonsson Funk Journal: Obstet Gynecol Date: 2014-06 Impact factor: 7.661
Authors: Matthew T Wolf; Christopher A Carruthers; Christopher L Dearth; Peter M Crapo; Alexander Huber; Olivia A Burnsed; Ricardo Londono; Scott A Johnson; Kerry A Daly; Elizabeth C Stahl; John M Freund; Christopher J Medberry; Lisa E Carey; Alejandro Nieponice; Nicholas J Amoroso; Stephen F Badylak Journal: J Biomed Mater Res A Date: 2013-07-19 Impact factor: 4.396
Authors: Daniela Ulrich; Sharon L Edwards; Kai Su; Jacinta F White; John A M Ramshaw; Graham Jenkin; Jan Deprest; Anna Rosamilia; Jerome A Werkmeister; Caroline E Gargett Journal: PLoS One Date: 2014-04-07 Impact factor: 3.240
Authors: Natharnia Young; Anna Rosamilia; John Arkwright; Joseph Lee; Miranda Davies-Tuck; Joan Melendez; Jerome Werkmeister; Caroline E Gargett Journal: Int Urogynecol J Date: 2016-11-29 Impact factor: 2.894
Authors: B Aghaei-Ghareh-Bolagh; S Mukherjee; K M Lockley; S M Mithieux; Z Wang; S Emmerson; S Darzi; C E Gargett; A S Weiss Journal: Mater Today Bio Date: 2020-10-13
Authors: Stuart Emmerson; Natharnia Young; Anna Rosamilia; Luke Parkinson; Sharon L Edwards; Aditya V Vashi; Miranda Davies-Tuck; Jacinta White; Kirstin Elgass; Camden Lo; John Arkwright; Jerome A Werkmeister; Caroline E Gargett Journal: Sci Rep Date: 2017-04-04 Impact factor: 4.379
Authors: Marina Gabriela M C Mori da Cunha; Katerina Mackova; Lucie Hajkova Hympanova; Maria Augusta T Bortolini; Jan Deprest Journal: Int Urogynecol J Date: 2021-01-23 Impact factor: 2.894