Document Detail


Dopamine microinjected into brainstem of awake rats affects baseline arterial pressure but not chemoreflex responses.
MedLine Citation:
PMID:  20188636     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Dopamine (DA) is a neuromodulator in the brainstem involved with the generation and modulation of the autonomic and respiratory activities. Here we evaluated the effect of microinjection of DA intracisterna magna (icm) or into the caudal nucleus tractus solitarii (cNTS) on the baseline cardiovascular and respiratory parameters and on the cardiovascular and respiratory responses to chemoreflex activation in awake rats. Guide cannulas were implanted in cisterna magna or cNTS and femoral artery and vein were catheterized. Respiratory frequency (f(R)) was measured by whole-body plethysmography. Chemoreflex was activated with KCN (iv) before and after microinjection of DA icm or into the cNTS bilaterally while mean arterial pressure (MAP), heart rate (HR) and f(R) were recorded. Microinjection of DA icm (n=13), but not into the cNTS (n=8) produced a significant decrease in baseline MAP (-15+/-1 vs 1+/-1mmHg) and HR (-55+/-11 vs -11+/-17bpm) in relation to control (saline with ascorbic acid, n=9) but no significant changes in baseline f(R). Microinjection of DA icm or into the cNTS produced no significant changes in the pressor, bradycardic and tachypneic responses to chemoreflex activation. These data show that a) DA icm affects baseline cardiovascular regulation, but not baseline f(R) and autonomic and respiratory components of chemoreflex and b) DA into the cNTS does not affect either the autonomic activity to the cardiovascular system or the autonomic and respiratory responses of chemoreflex activation.
Authors:
Waldyr M Oliva; Erica M Granjeiro; Leni G H Bongamba; Ricardo A Mendes; Benedito H Machado
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-02-26
Journal Detail:
Title:  Autonomic neuroscience : basic & clinical     Volume:  155     ISSN:  1872-7484     ISO Abbreviation:  Auton Neurosci     Publication Date:  2010 Jun 
Date Detail:
Created Date:  2010-05-31     Completed Date:  2010-08-20     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100909359     Medline TA:  Auton Neurosci     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  73-81     Citation Subset:  IM    
Affiliation:
Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, SP, Brazil.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / drug effects*,  physiology
Brain Stem / drug effects*,  metabolism
Chemoreceptor Cells / drug effects*
Consciousness
Dopamine / administration & dosage*,  metabolism
Enzyme Inhibitors / pharmacology
Heart Rate / drug effects*,  physiology
Male
Microinjections
Plethysmography, Whole Body
Potassium Cyanide / pharmacology
Rats
Rats, Wistar
Respiratory Rate / drug effects,  physiology
Chemical
Reg. No./Substance:
0/Enzyme Inhibitors; 151-50-8/Potassium Cyanide

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