Document Detail

Myoendometrial versus placental uterine arteries: structural, mechanical, and functional differences in late-pregnant rabbits.
MedLine Citation:
PMID:  9240609     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: This study compared late-pregnant radial uterine arteries that supplied the placenta versus the myoendometrium to evaluate differences in active and passive mechanical properties. STUDY DESIGN: Pressurized segments of placental versus myoendometrial radial uterine arteries from late-pregnant (day 28 to 30) New Zealand White rabbits (n = 12) were compared in vitro for differences in luminal diameter, wall thickness, distensibility, and intrinsic tone as a function of transmural pressure. RESULTS: Both types of arteries responded to increased transmural pressure with active vasoconstriction; however, the amount of tone present in myoendometrial arteries was significantly greater than in placental arteries (percent tone at 75 mm Hg = 39% +/- 3% for myoendometrial versus 31% +/- 2% for placental arteries, p < 0.01). Measurements of unpressurized, fully relaxed arteries revealed that placental arteries were 38% larger in diameter and had thicker walls than myoendometrial arteries did. However, myoendometrial arteries were significantly more distensible at transmural pressures >5 mm Hg. CONCLUSIONS: The increased size and diminished tone of placental compared with adjacent myoendometrial arteries would favor increased blood flow to the placenta; differences in size and passive mechanical properties suggest that a localized factor(s) originating from the fetus or placenta contributes to the gestational enlargement of those arteries that perfuse the placenta.
M J Cipolla; N D Binder; G Osol
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  American journal of obstetrics and gynecology     Volume:  177     ISSN:  0002-9378     ISO Abbreviation:  Am. J. Obstet. Gynecol.     Publication Date:  1997 Jul 
Date Detail:
Created Date:  1997-08-19     Completed Date:  1997-08-19     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370476     Medline TA:  Am J Obstet Gynecol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  215-21     Citation Subset:  AIM; IM    
Department of Surgery, Oregon Health Sciences University, Portland 97201, USA.
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MeSH Terms
Arteries / anatomy & histology,  physiology
Models, Biological
Myometrium / blood supply*,  physiology
Placenta / blood supply*,  physiology
Pregnancy, Animal / physiology*
Regional Blood Flow
Uterus / blood supply*,  physiology*
Vascular Resistance / physiology
Vasoconstriction / physiology
Grant Support
44941//PHS HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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