Document Detail


Tubuloglomerular feedback during elevated renal venous pressure.
MedLine Citation:
PMID:  4051005     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Interstitial hydrostatic and oncotic pressures are believed to influence the sensitivity of the tubuloglomerular feedback (TGF) control. To further investigate this hypothesis, three groups of experiments with elevated renal venous pressure (Prv) were conducted. We investigated 1) the stop-flow pressure (Psf) feedback response; 2) urine flow rate, glomerular filtration rate (GFR), subcapsular interstitial hydrostatic pressure (Psc), and interstitial oncotic pressure (pi int); and 3) the proximal-distal single nephron glomerular filtration rate (SNGFR). The results showed that the Psf feedback response was unaffected by Prv elevation. Psc increased from 0.5 to 3.5 mmHg and pi int increased from 2.1 to 5.8 mmHg; thus, no change in net interstitial pressure (Psc - pi int) was found during elevated Prv. There was a significant proximal-distal SNGFR difference during both control and elevated Prv (8.0 and 6.3 nl/min, respectively). A 20% reduction in total GFR and SNGFR was observed at increased Prv. In separate experiments using the same protocol, a 5% body wt/h volume expansion with saline was induced before Prv was elevated. During volume expansion, TGF sensitivity declined and net interstitial pressure increased, both of which were normalized by increasing Prv. The results show that the TGF sensitivity is normal during elevated Prv to 20 mmHg and that the increase in Psc during this condition is counter-balanced by an increase in pi int. In addition, the decrease in GFR and SNGFR during increased Prv cannot be explained by a change in TGF activity. However, these findings indicate that both interstitial hydrostatic and oncotic pressures may influence the resetting of the TGF sensitivity.
Authors:
U Boberg; A E Persson
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The American journal of physiology     Volume:  249     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1985 Oct 
Date Detail:
Created Date:  1985-11-12     Completed Date:  1985-11-12     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  F524-31     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Extracellular Space / physiology
Feedback
Glomerular Filtration Rate
Hydrostatic Pressure
Kidney Glomerulus / physiology*
Kidney Tubules / physiology*
Rats
Rats, Inbred Strains
Renal Veins / physiology*
Venous Pressure

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


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