Document Detail


The effect of intracerebroventricular dopamine administration on the respiratory response to hypoxia.
MedLine Citation:
PMID:  12086150     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Acute hypoxia produces an increase in ventilation. When the hypoxia is sustained, the initial increase in ventilation is followed a decrease in ventilation. The precise mechanism of this decline in ventilation during sustained hypoxia is unknown. Recent studies hypothesized that the accumulation of dopamine in the central nervous system might have a major role in production of hypoxic respiratory depression. The purpose of this study was to examine whether dopamine has an effect on occurance of central ventilatory depression which is seen in acute hypoxia in peripheral chemoreceptors denervated animals. The experiment were conducted in rabbits anesthetized with Na-pentobarbital (25 mg x kg(-1) i.v.). For intracerebroventricular (i.c.v.) injections of dopamine (1 microg) in each animal, canula was placed in left lateral cerebral ventricle by stereotaxic method. Respiratory frequency (f x min(-1)), tidal volume (V(T)) ventilation minute volume (V(E)) and systemic arterial blood pressure (BP) were recorded during air and 3 minutes hypoxic gas mixture (8%O2-92%N2) breathing. I.c.v. administration of dopamine during normoxia decreased V(T), f, V(E) and BP, significantly. When rabbits were injected with an i.c.v. dopamine on hypoxic gas mixture breathing in control animals, there was depression of hypoxic ventilatory responses. After i.c.v. administration of dopamine antagonists haloperidol (0.1 mg) and domperidone (0.07 mg) in chemodenervated rabbits, the significant increases in V(T), V(E) and BP were observed. On the breathing of hypoxic gas mixture of chemodenervated and i.c.v. dopamine antagonists administrated rabbits, hypoxic depression was completely abolished. These results of this study show that accumulation of dopamine in the brain seems to reduce the response of the central control mechanisms to chemoreceptor impulses during normoxia and hypoxia. In conclusion present study suggests important role played by central dopaminergic pathways in the occurence of acute hypoxic ventilatory depression.
Authors:
Ibrahim Güner; Nermin Yelmen; Gülderen Sahin; Tülin Oruç
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Tohoku journal of experimental medicine     Volume:  196     ISSN:  0040-8727     ISO Abbreviation:  Tohoku J. Exp. Med.     Publication Date:  2002 Apr 
Date Detail:
Created Date:  2002-06-27     Completed Date:  2003-01-06     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0417355     Medline TA:  Tohoku J Exp Med     Country:  Japan    
Other Details:
Languages:  eng     Pagination:  219-30     Citation Subset:  IM    
Affiliation:
Department of Physiology, Cerrahpaşa Medical Faculty, University of Istanbul, Turkey.
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MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia
Cerebrovascular Circulation
Domperidone / pharmacology
Dopamine / administration & dosage,  pharmacology*
Dopamine Antagonists / pharmacology
Haloperidol / pharmacology
Rabbits
Respiratory Function Tests
Respiratory Physiological Phenomena / drug effects*
Chemical
Reg. No./Substance:
0/Dopamine Antagonists; 52-86-8/Haloperidol; 57808-66-9/Domperidone

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


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