Document Detail


Ascorbyl palmitate augments hypoxic respiratory response in the cat.
MedLine Citation:
PMID:  15153781     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The redox signaling is germane for the hypoxia-sensing mechanisms at the carotid body. This raises the strong possibility that agents possess reducing and antioxidant attributes, such as ascorbate, could influence the hypoxic respiratory response. However, water solubility of ascorbate makes its effectiveness at membrane-associated target sites dubious. In this study, we sought to determine the effect of ascorbyl-6-palmitate (AP), a lipid-soluble derivative of ascorbate which penetrates biomembranes, on hypoxic respiration in the anesthetized, paralyzed and ventilated cat. AP was given by gavage: 600 mg/kg daily for 6 days before the beginning of the acute experiment. Respiration was then assessed from the phrenic electroneurogram, from which peak phrenic amplitude, a surrogate of tidal component, respiratory frequency, and their product, the minute phrenic output, were quantified. The response to normocapnic hypoxia, 7% O(2) in N(2), in the AP-treated cats was compared with that in controls. We found that AP augmented hypoxic respiration, delayed the appearance of hypoxic depression and decreased it, although the stimulatory/depressant character was preserved. The results suggest that the ascorbate moiety of AP interacts with the hypoxia-sensing mechanisms. Ascorbate may affect hypoxic respiration at multiple stages of chemotransduction pathways, which are subject to continuing uncertainties. The study highlights the augmentative effect of AP, a redox modulator, on hypoxic respiration, which may have a therapeutic potential.
Authors:
Mieczysław Pokorski; Ahlam Ramadan; Magdalena Marczak
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of biomedical science     Volume:  11     ISSN:  1021-7770     ISO Abbreviation:  J. Biomed. Sci.     Publication Date:    2004 Jul-Aug
Date Detail:
Created Date:  2004-05-21     Completed Date:  2005-03-22     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9421567     Medline TA:  J Biomed Sci     Country:  Switzerland    
Other Details:
Languages:  eng     Pagination:  465-71     Citation Subset:  IM    
Copyright Information:
Copyright 2004 National Science Council, ROC and S. Karger AG, Basel
Affiliation:
Department of Respiratory Research, Medical Research Center, Polish Academy of Sciences, Warsaw, Poland. mpokorski@cmdik.pan.pl
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MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia / physiopathology*
Ascorbic Acid / administration & dosage,  analogs & derivatives*,  pharmacology*
Blood Gas Analysis
Blood Pressure
Cats
Electrophysiology
Oxidation-Reduction
Phrenic Nerve / physiology
Respiration / drug effects*
Signal Transduction
Chemical
Reg. No./Substance:
137-66-6/6-O-palmitoylascorbic acid; 50-81-7/Ascorbic Acid

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


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