Document Detail


Glutamatergic receptors of the rostral ventrolateral medulla are involved in the ventilatory response to hypoxia.
MedLine Citation:
PMID:  15766901     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Rostral ventrolateral medulla (RVLM) is a region in the brainstem that is involved in the physiologic responses to hypoxia (i.e. hyperventilation and regulated hypothermia) and contains l-glutamate receptors. Therefore, we examined the effects of blocked of glutamatergic receptors in the RVLM on hypoxic hyperventilation and regulated hypothermia. Ventilation (V(E)) and body temperature (T(b)) were measured before and after bilaterally microinjection of kynurenic acid (KYN, 5 nmol/100 nl, an ionotropic glutamatergic receptors antagonist) and alpha-methyl-4-carboxyphenylglycine (MCPG, 10 nmol/100 nl, a metabotropic glutamatergic receptors antagonist) into the RVLM, followed by a 60-min period of hypoxia exposure. Control rats received microinjection of saline (vehicle). KYN or MCPG into the RVLM did not change V(E) and T(b) under normoxia, but reduced the hypoxic hyperventilation due to a lower tidal volume, although regulated hypothermia persisted. These data suggest that glutamatergic receptors in the RVLM are involved in the ventilatory response to hypoxia, exercising an excitatory modulation of the RVLM neurons, but play no role in hypoxia-induced hypothermia.
Authors:
Patricia M de Paula; Luiz G S Branco
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Respiratory physiology & neurobiology     Volume:  146     ISSN:  1569-9048     ISO Abbreviation:  Respir Physiol Neurobiol     Publication Date:  2005 Apr 
Date Detail:
Created Date:  2005-03-15     Completed Date:  2005-05-20     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  101140022     Medline TA:  Respir Physiol Neurobiol     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  125-34     Citation Subset:  IM    
Affiliation:
Departamento de Ciencias Biologicas, Faculdade de Medicina do Triangulo Mineiro, Uberaba, MG, Brazil. depaula@uthscsa.edu
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MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia / physiopathology*
Benzoates / pharmacology
Body Temperature / physiology
Body Temperature Regulation / drug effects
Drug Interactions
Excitatory Amino Acid Antagonists / pharmacology
Glycine / analogs & derivatives*,  pharmacology
Hyperventilation / physiopathology
Hypothermia / chemically induced,  physiopathology
Kynurenic Acid / pharmacology
Male
Medulla Oblongata / drug effects,  physiopathology*
Microinjections / methods
Pulmonary Ventilation / drug effects
Rats
Rats, Wistar
Receptors, Glutamate / physiology*
Tidal Volume / drug effects
Time Factors
Ventilators, Mechanical
Chemical
Reg. No./Substance:
0/Benzoates; 0/Excitatory Amino Acid Antagonists; 0/Receptors, Glutamate; 146669-29-6/alpha-methyl-4-carboxyphenylglycine; 492-27-3/Kynurenic Acid; 56-40-6/Glycine

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


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