Document Detail


Aldosterone acts on the kidney, not the brain, to cause mineralocorticoid hypertension in sheep.
MedLine Citation:
PMID:  12023692     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: To determine the extent to which mineralocortioid hypertension depends on a direct action of aldosterone on the kidney or on the brain. METHODS: Studies were performed in conscious sheep that were previously uninephrectomized, implanted with silastic cannulae in the renal artery of the remaining kidney, and had guide tubes implanted over the lateral cerebral ventricles. The effect of aldosterone, infused either intrarenally (i.r.; 2 microg/h) or intravenously (i.v.; 2 and 10 microg/h) for 10 days (n = 5), on arterial pressure and fluid and electrolyte balance was determined. The i.r. (2 microg/h) and i.v. (10 microg/h) doses were calculated to give similar intrarenal concentrations of aldosterone. In a further study, the effect of intracerebroventricular (i.c.v.) infusion of aldosterone (2 microg/h for 21 days) on arterial pressure was examined (n = 5). RESULTS: Infusion of aldosterone caused a progressive increase in mean arterial pressure from 83 +/- 3 mmHg to a maximum of 100 +/- 4 mmHg (P < 0.001) with 2 microg/h i.r. and from 84 +/- 3 mmHg to a maximum of 104 +/- 4 mmHg (P < 0.001) with 10 microg/h i.v., both by day 7. With both infusions there were similar increases in plasma [Na+] and decreases in plasma [K+] and total protein concentration (P < 0.05) between days 3 and 5; these were maintained throughout the infusion. There were no significant changes with i.v. aldosterone (2 microg/h). Long-term i.c.v. infusion of aldosterone (2 microg/h for 21 days) caused no change in arterial pressure. CONCLUSIONS: In conscious sheep the hypertensive response to aldosterone resulted from an action on the kidney, with no evidence for a direct action on the brain.
Authors:
Leopoldo A Sosa Le?n; Michael J McKinley; Robin M McAllen; Clive N May
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of hypertension     Volume:  20     ISSN:  0263-6352     ISO Abbreviation:  J. Hypertens.     Publication Date:  2002 Jun 
Date Detail:
Created Date:  2002-05-22     Completed Date:  2002-12-04     Revised Date:  2010-03-23    
Medline Journal Info:
Nlm Unique ID:  8306882     Medline TA:  J Hypertens     Country:  England    
Other Details:
Languages:  eng     Pagination:  1203-8     Citation Subset:  IM    
Affiliation:
Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria, Australia.
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MeSH Terms
Descriptor/Qualifier:
Aldosterone / administration & dosage,  pharmacology*
Animals
Blood / metabolism
Blood Pressure / drug effects
Body Fluids / metabolism
Brain / drug effects
Electrolytes / metabolism
Female
Hormones / blood
Hypertension / chemically induced*,  metabolism,  physiopathology
Infusions, Intravenous
Injections
Injections, Intraventricular
Kidney / drug effects*
Mineralocorticoids*
Sheep
Time Factors
Chemical
Reg. No./Substance:
0/Electrolytes; 0/Hormones; 0/Mineralocorticoids; 52-39-1/Aldosterone
Comments/Corrections
Comment In:
J Hypertens. 2002 Jun;20(6):1079-80   [PMID:  12023673 ]

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


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