| Impact of pregnancy and vaginal delivery on the passive and active mechanics of the rat vagina. | |
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MedLine Citation:
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PMID: 20824342 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Remodeling of vaginal extracellular matrix and smooth muscle likely plays a critical role in reducing the risk of maternal injury during vaginal delivery by altering the mechanical properties to increase distension and reduce stress. Long-Evans rats were divided into five groups to examine the passive mechanical and active contractile properties throughout pregnancy and postpartum: virgin (n=17), mid-pregnant (Day 14-16, n=12), late-pregnant (Day 20-22, n=14), immediate postpartum (0-2 h after delivery, n=14), and 4 week postpartum (n=15). Longitudinal sections of vaginal tissue were loaded to failure uniaxially for passive mechanical or active contractile properties were examined. For passive mechanics, the tangent modulus decreased 45% by mid-pregnancy and immediately postpartum (p<0.001). The ultimate strain continuously increased up to 43% higher than virgin animals (p=0.007) in the immediate postpartum group. For active mechanics, the maximal contractile force was 36-56% lower through immediate postpartum animals, and was significantly more sensitive to K+ throughout pregnancy and postpartum (p=0.003). The changes observed in the passive and active properties of the rat vagina are consistent with what would be expected from a tissue that is remodeling to maximize its ability to distend at the time of vaginal delivery to facilitate passage of the fetus with minimal injury. |
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Authors:
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Andrew Feola; Pamela Moalli; Marianna Alperin; Robbie Duerr; Robin E Gandley; Steven Abramowitch |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural Date: 2010-09-08 |
Journal Detail:
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Title: Annals of biomedical engineering Volume: 39 ISSN: 1521-6047 ISO Abbreviation: Ann Biomed Eng Publication Date: 2011 Jan |
Date Detail:
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Created Date: 2010-12-24 Completed Date: 2011-04-11 Revised Date: 2011-07-26 |
Medline Journal Info:
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Nlm Unique ID: 0361512 Medline TA: Ann Biomed Eng Country: United States |
Other Details:
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Languages: eng Pagination: 549-58 Citation Subset: IM |
Affiliation:
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Musculoskeletal Research Center, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Delivery, Obstetric* Elastic Modulus / physiology Female Muscle Contraction / physiology* Muscle, Smooth / physiology* Pregnancy Pregnancy, Animal / physiology* Rats Rats, Long-Evans Stress, Mechanical Tensile Strength Vagina / physiology* |
| Grant Support | |
ID/Acronym/Agency:
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K12HD-043441/HD/NICHD NIH HHS; R01 HD045590-05/HD/NICHD NIH HHS; R01HD-045590/HD/NICHD NIH HHS |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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