Document Detail


Pressure natriuresis after adrenomedullin in anesthetized spontaneously hypertensive rats.
MedLine Citation:
PMID:  9323000     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Adrenomedullin (ADM), a peptide with potent vasodilatory and natriuretic actions, is elevated in patients with essential hypertension. Because pharmacological doses of ADM result in renal vasodilation and natriuresis, it has been suggested that ADM may play a modulatory role in hypertension through potential actions on renal pressure natriuresis. However, it is unclear whether elevation of plasma ADM within the pathophysiological range has similar actions. To determine the effects of pathophysiological doses of ADM on blood pressure and on the relationship between renal perfusion pressure (RPP) and renal hemodynamics and sodium excretion, renal function was determined at RPPs of 80, 105, 130, and 155 mm Hg in spontaneously hypertensive rats (SHR) infused with ADM at 50 ng x kg(-1) x min(-1) (ADM-50, n=5) and at 100 ng x kg(-1) x min(-1) (ADM-100, n=5) and in control SHR (n=5). Decreasing RPP from 155 to 80 mm Hg in control SHR decreased (P<.05) absolute sodium excretion from 0.81+/-0.25 to 0.04+/-0.02 microEq/min, fractional sodium excretion from 0.32+/-0.11% to 0.06+/-0.04%, and urine flow rate from 11.5+/-2.8 to 1.03+/-0.31 microL/min. ADM infusion elevated (P<.05) plasma ADM levels in ADM-infused SHR (679+/-47 pg/mL in ADM-50, 858+/-79 in ADM-100) compared with control (79.5+/-27.8). However, although reduction of RPP from 155 to 80 mm Hg in ADM rats decreased absolute sodium excretion (ADM-50, 0.98+/-0.10 to 0.09+/-0.04 microEq/min; ADM-100, 0.95+/-0.09 to 0.07+/-0.02 microEq/min), fractional sodium excretion (ADM-50, 0.31+/-0.03% to 0.17+/-0.04%; ADM-100, 0.33+/-0.02% to 0.09+/-0.01%), and urine flow (ADM-50, 13.6+/-1.4 to 1.73+/-0.75 microL/min; ADM-100, 13.5+/-1.5 to 1.07+/-0.16 microL/min), these decreases were not different from values found in controls. Renal plasma flow and glomerular filtration rate were also similar in control and ADM-treated SHR at each level of RPP. Thus, acute increases in ADM to levels found in pathophysiological conditions have no effect on blood pressure, pressure natriuresis, or renal autoregulation in the SHR. These findings do not support the hypothesis that ADM serves as a modulating factor in hypertension, at least in the SHR.
Authors:
T Kurashina; A R Patel; J P Granger; K A Kirchner
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Hypertension     Volume:  30     ISSN:  0194-911X     ISO Abbreviation:  Hypertension     Publication Date:  1997 Sep 
Date Detail:
Created Date:  1997-10-16     Completed Date:  1997-10-16     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  660-3     Citation Subset:  IM    
Affiliation:
Department of Veterans Affairs Medical Center, Jackson, MS 39216, USA.
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MeSH Terms
Descriptor/Qualifier:
Adrenomedullin
Anesthesia
Animals
Antihypertensive Agents / pharmacology*
Blood Pressure / drug effects*
Glomerular Filtration Rate / drug effects
Hypertension / physiopathology*
Male
Natriuresis / drug effects*
Peptides / pharmacology*
Rats
Rats, Inbred SHR
Renal Circulation / drug effects
Chemical
Reg. No./Substance:
0/Antihypertensive Agents; 0/Peptides; 148498-78-6/Adrenomedullin

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


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