| Transient regulation of transport by pericytes in venular microvessels via trapped microdomains. | |
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MedLine Citation:
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PMID: 18216252 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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A phenomenon that has defied explanation for two decades is the time scale for transient reabsorption in the classic experiments of Michel and Phillips on individually perfused frog mesentery microvessels. One finds that transient reabsorption lasts <2 min before a new steady state of low filtration is established when the lumen pressure is abruptly dropped from a high to a low value. Our experiments in frog and rat venular microvessels under a variety of conditions revealed the same time trend for new steady states to be established as in Michel and Phillips' experiments. In contrast, one theoretically predicts herein that the time required for the tissue albumin concentration to increase to values for a new steady state to be achieved through reabsorption is in the order of several hours. In this paper we propose a new hypothesis and theoretical model for this rapid regulation, namely that pericytes covering the interendothelial cleft exits create small trapped microdomains outside the cleft exits which regulate this transient behavior. Our electron microscopy studies on rat mesenteric venular microvessels reveal an average pericyte coverage of approximately 85%. The theoretical model based on this ultrastructural study predicts an equilibration time on the order of 1 min when the lumen pressure is abruptly lowered. The basic concept of a trapped microdomain can also be extended to microdomains in the interstitial space surrounding skeletal muscle capillaries. |
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Authors:
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X Zhang; R H Adamson; F E Curry; S Weinbaum |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural Date: 2008-01-23 |
Journal Detail:
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Title: Proceedings of the National Academy of Sciences of the United States of America Volume: 105 ISSN: 1091-6490 ISO Abbreviation: Proc. Natl. Acad. Sci. U.S.A. Publication Date: 2008 Jan |
Date Detail:
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Created Date: 2008-01-30 Completed Date: 2008-02-25 Revised Date: 2009-11-18 |
Medline Journal Info:
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Nlm Unique ID: 7505876 Medline TA: Proc Natl Acad Sci U S A Country: United States |
Other Details:
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Languages: eng Pagination: 1374-9 Citation Subset: IM |
Affiliation:
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The Leni and Peter W. May Department of Orthopaedics, Mount Sinai School of Medicine, New York, NY 10029, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Aorta Endothelium, Vascular / metabolism*, physiology, ultrastructure Male Mesentery / blood supply, metabolism*, ultrastructure Microcirculation / metabolism, ultrastructure Pericytes / metabolism*, ultrastructure Protein Structure, Tertiary / physiology Protein Transport / physiology Rana pipiens Rana temporaria Rats Rats, Sprague-Dawley Serum Albumin / chemistry*, metabolism*, physiology Venules / metabolism*, physiology, ultrastructure |
| Grant Support | |
ID/Acronym/Agency:
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AR41210/AR/NIAMS NIH HHS; AR48699/AR/NIAMS NIH HHS; HL44485/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Serum Albumin |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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