Document Detail

Effects of flow rate on proximal tubule ultrastructure.
MedLine Citation:
PMID:  3631286     Owner:  NLM     Status:  MEDLINE    
In this study we investigated the ultrastructure of the proximal tubule during alterations in fluid flow to determine whether previously observed changes in solute and water reabsorption may be related to alterations in cell ultrastructure. In each kidney, two proximal tubules (S2 segments) were perfused simultaneously at 5 and 45 nl/min. Subsequently, cell ultrastructure of control and experimental tubules was examined by electron microscopy in combination with morphometry. Changes in flow rate greatly modified the geometry of the tubule epithelium. Enhanced flow increased luminal diameter and decreased cell height. The number of microvilli per square micrometer of luminal epithelial surface area decreased with increased flow rate from a control value of 42.5 to 35.5 at high flow. However, the total number of microvilli per millimeter tubule length did not change. Thus the distance between microvilli was dependent on flow rate and was estimated to be 621, 741, and 904 A in low flow, control, and high flow tubules, respectively. We suggest that increased flow rate, perhaps by altering transepithelial hydrostatic pressure gradients, leads to an increase in the distance between the microvilli and to other alterations in cellular ultrastructure that may contribute to the augmentation of solute and water reabsorption.
A B Maunsbach; G H Giebisch; B A Stanton
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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:  The American journal of physiology     Volume:  253     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1987 Sep 
Date Detail:
Created Date:  1987-10-22     Completed Date:  1987-10-22     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  F582-7     Citation Subset:  IM    
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MeSH Terms
Biological Transport
Epithelium / ultrastructure
Hydrostatic Pressure
Kidney Tubules, Proximal / physiology,  ultrastructure*
Microscopy, Electron
Microvilli / ultrastructure
Water-Electrolyte Balance
Grant Support
17433//PHS HHS; 34533//PHS HHS

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

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