Document Detail

Resistive loading reduces ventilatory response to strychnine in anesthetized rabbits.
MedLine Citation:
PMID:  9839719     Owner:  NLM     Status:  MEDLINE    
Breathing through an inspiratory resistance induces a hypoventilation in mammals despite an increased diaphragmatic activity. We showed in previous works that an increase in GABA and endogenous opioid release in the central respiratory network could explain in part the inadequate increase in the inspiratory drive during inspiratory loading. In the present experiment, we speculated about an additional role of glycine, another inhibitory neurotransmitter. The ventilatory effects of the glycine antagonist strychnine were evaluated in two groups of anesthetized rabbits, breathing either through an inspiratory resistive load (IRL) or not (control group). In the control group, strychnine raised (+7%, P < 0.05) the minute ventilation, V, and the rate of increase in integrated diaphragmatic discharge (Edi peak/T peak: +29%, P < 0.01). In the IRL group, strychnine did not change V and produced a lesser increase in Edi peak/T peak (+9%, P < 0.05). In both groups, strychnine induced a tonic diaphragmatic discharge. These data show that there is a weak inhibition of inspiration by glycine during resistive loading, but the effect is modest compared with that observed during unloaded ventilation. Thus, it seems that IRL breathing reduces the efficacy and/or the release of this neurotransmitter in the central nervous system, in this experimental situation.
S Delpierre; E Balzamo; Y Jammes
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Neuroscience letters     Volume:  255     ISSN:  0304-3940     ISO Abbreviation:  Neurosci. Lett.     Publication Date:  1998 Oct 
Date Detail:
Created Date:  1999-03-01     Completed Date:  1999-03-01     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  7600130     Medline TA:  Neurosci Lett     Country:  IRELAND    
Other Details:
Languages:  eng     Pagination:  29-32     Citation Subset:  IM    
Laboratoire de Physiologie Respiratoire, Faculté de Médecine Timone, Marseille, France.
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MeSH Terms
Airway Resistance / physiology*
Diaphragm / physiology
Glycine Agents / pharmacology*
Reference Values
Respiration / drug effects*
Strychnine / pharmacology*
Reg. No./Substance:
0/Glycine Agents; 57-24-9/Strychnine

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

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