Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Nov;35(11):2141-2152.
doi: 10.1007/s00192-024-05943-9. Epub 2024 Oct 7.

Mechanical Stress-Oxidative Stress Axis: Biological Basis in the Vaginal Wall and Pelvic Floor Muscles of Rats with Simulated Birth Injury

Qing Wang  1   2   3 , Xiaotong Wu  1   2   3 , Shiyan Wang  1   2   3 , Bing Xie  1   2   3 , Xiuli Sun  4   5   6 , Jianliu Wang  1   2   3
Affiliations

Mechanical Stress-Oxidative Stress Axis: Biological Basis in the Vaginal Wall and Pelvic Floor Muscles of Rats with Simulated Birth Injury

Qing Wang et al. Int Urogynecol J. 2024 Nov.

Abstract

Introduction and hypothesis: Vaginal delivery and resulting pelvic floor muscle (PFM) dysfunction are significant risk factors for pelvic floor dysfunction (PFD). Despite this, the biological basis underlying PFD after childbirth remain unclear. This study was aimed at assessing the early response of the vaginal wall and PFM to simulated birth injury (SBI) in rats.

Methods: Forty female Sprague-Dawley rats were divided into four groups: control (sham operation), and 1, 4, and 14 days post-injury. In the SBI groups, a catheter was inserted into the vagina with 130 g of weight attached to the end, and the balloon was inflated to 5 ml for 2 h. Evaluation of vaginal tissues and PFMs included histological, immunohistochemical, Western blot, and uniaxial biomechanical testing.

Results: In the vaginal wall, the SBI group showed significantly lower COL1A1 expression and higher MMP-2 and MMP-9 expression. At 4 and 14 days post-injury, there was a significant decrease in PFM fiber area and increased collagen content. The SBI group also exhibited significant increases in the expression of Nrf2, NQO1, HO-1, and SOD-2, indicating involvement of oxidative stress in both the vaginal wall and PFMs. Protein expression of Pax7 and MyoG, as well as the number of fibers with centralized nuclei, continued to increase significantly after SBI. Additionally, the vaginal wall of the SBI group showed a decreasing trend in tensile strength and elastic modulus, with a greater ultimate strain.

Conclusion: Extracellular matrix remodeling, oxidative stress, decreased biomechanical properties, and muscle dysmyogenesis may collectively contribute to increased susceptibility to PFD development.

Keywords: Pelvic floor dysfunctions; Pelvic floor muscle; Simulated birth injury; Vaginal delivery; Vaginal wall.

PubMed Disclaimer

Conflict of interest statement

Declarations. Ethics Approval: The procedures were approved by the Medical Ethics Committee of Peking University People's Hospital (No. 2021PHE078) and were performed in accordance with the relevant guidelines and regulations. Furthermore, this study was conducted in compliance with the ARRIVE guidelines. Conflicts of Interest: None.

Similar articles

See all similar articles

Cited by

References

    1. Wang Q, Wu X, Jia Y, Zhang D, Sun X, Wang J. Gestational diabetes mellitus and pelvic floor function 6 weeks postpartum in Chinese women. Int Urogynecol J. 2023;34(7):1619–26. https://doi.org/10.1007/s00192-022-05438-5 . - DOI - PubMed
    1. Pang H, Zhang L, Han S, Li Z, Gong J, Liu Q, Liu X, Wang J, Xia Z, Lang J, Xu T, Zhu L. A nationwide population-based survey on the prevalence and risk factors of symptomatic pelvic organ prolapse in adult women in China—a pelvic organ prolapse quantification system-based study. BJOG. 2021;128(8):1313–23. https://doi.org/10.1111/1471-0528.16675 . - DOI - PubMed - PMC
    1. Duran P, Boscolo Sesillo F, Cook M, Burnett L, Menefee SA, Do E, French S, Zazueta-Damian G, Dzieciatkowska M, Saviola AJ, Shah MM, Sanvictores C, Osborn KG, Hansen KC, Shtrahman M, Christman KL, Alperin M. Proregenerative extracellular matrix hydrogel mitigates pathological alterations of pelvic skeletal muscles after birth injury. Sci Transl Med. 2023;15(707):eabj3138. https://doi.org/10.1126/scitranslmed.abj3138 . - DOI - PubMed - PMC
    1. Tunn R, Baessler K, Knupfer S, Hampel C. Urinary incontinence and pelvic organ prolapse in women. Dtsch Arztebl Int. 2023;120(5):71–80. https://doi.org/10.3238/arztebl.m2022.0406 . - DOI - PubMed - PMC
    1. Cattani L, Decoene J, Page AS, Weeg N, Deprest J, Dietz HP. Pregnancy, labour and delivery as risk factors for pelvic organ prolapse: a systematic review. Int Urogynecol J. 2021;32(7):1623–31. https://doi.org/10.1007/s00192-021-04724-y . - DOI - PubMed

LinkOut - more resources