Document Detail


Nitric oxide in the ventrolateral medulla regulates sympathetic responses to systemic hypoxia in pigs.
MedLine Citation:
PMID:  9688957     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The role of nitric oxide (NO) in the regulation of sympathetic activity during hypoxia was studied in anesthetized pigs (n = 21). Hypoxia (fractional concentration of O2 in inspired air = 0.1) increased pulmonary arterial pressure and decreased arterial blood pressure and peripheral vascular resistance. Renal sympathetic nerve activity (RSNA) was moderately increased during hypoxia but decreased instantaneously on reoxygenation. Blockade of NO synthesis by NG-nitro-L-arginine (L-NNA, 0.3 mmol/l) administered to the ventral surface of the medulla oblongata (VLM) significantly enhanced RSNA increases induced by hypoxia and abolished the RSNA response to reoxygenation. Furthermore, L-NNA significantly reduced peripheral hypoxic vasodilation but did not affect pulmonary vasoconstriction. The inactive enantiomer D-NNA had no measurable effects at the same concentration. Actions of L-NNA were effectively counteracted by the NO donor S-nitroso-N-acetyl-penicillamine (0.1 mmol/l). Deafferentiation (carotid sinus and vagal nerves cut) abolished sympathetic responses to hypoxia and their modulation by NO. The results suggest that activation of peripheral chemoreceptors induces NO release in the VLM that buffers sympathoexcitation during hypoxia and contributes to sympathoinhibition during reoxygenation.
Authors:
J Zanzinger; J Czachurski; H Seller
Related Documents :
11009437 - Hypoxic pulmonary vasoconstriction is modified by p-450 metabolites.
2536247 - Regional adrenal blood flow during hypoxia in anesthetized, ventilated dogs.
647497 - Microangiography and vascular permeability of the subependymal matrix in the premature ...
3422547 - Intravenous pgf2 alpha infusion does not enhance hypoxic pulmonary vasoconstriction dur...
22189267 - Codon 72 polymorphism (rs1042522) of tp53 is associated with changes in diastolic blood...
20365727 - Cluster formation, waterlike anomalies, and re-entrant melting for a family of bounded ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The American journal of physiology     Volume:  275     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1998 Jul 
Date Detail:
Created Date:  1998-08-27     Completed Date:  1998-08-27     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  R33-9     Citation Subset:  IM    
Affiliation:
I. Physiologisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia / physiopathology*
Blood Pressure
Cardiac Output
Heart Rate
Hemodynamics / drug effects,  physiology*
Infusions, Parenteral
Kidney / innervation
Medulla Oblongata / drug effects,  physiology,  physiopathology*
Nitric Oxide / physiology*
Nitroarginine / administration & dosage,  pharmacology*
Penicillamine / analogs & derivatives,  pharmacology
Pulmonary Artery / physiology,  physiopathology
S-Nitroso-N-Acetylpenicillamine
Stereotaxic Techniques
Swine
Sympathetic Nervous System / physiology,  physiopathology*
Vascular Resistance
Chemical
Reg. No./Substance:
10102-43-9/Nitric Oxide; 2149-70-4/Nitroarginine; 52-67-5/Penicillamine; 79032-48-7/S-Nitroso-N-Acetylpenicillamine

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


Previous Document:  Misty (m) affects growth traits.
Next Document:  Effect of chronic bradykinin administration on insulin action in an animal model of insulin resistan...