Document Detail


Regulation of fetal breathing.
MedLine Citation:
PMID:  8713720     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Traditionally, the idea of transient asphyxia plus some degree of cold stimulation has been used to explain the establishment of continuous breathing at birth. This idea was nurtured by observations made in the acute fetal preparation at a time when fetal breathing was considered absent. Experimental observations made in the past two decades have challenged this traditional view. First, complete peripheral chemodenervation, essential to the hypoxic stimulus theory, did not affect fetal breathing or the establishment of continuous breathing at birth. Second, occlusion of the umbilical cord in utero, as long as some oxygenation is provided to the fetus in order to avoid fetal hypoxaemia, establishes continuous breathing in utero, in the absence of all sensorial input thought to be important for the establishment of continuous breathing. These observations led us to hypothesize the presence of a placental factor responsible for the inhibition of breathing in utero. This placental factor appears to be a peptide with a molecular mass between 3.5 and 10 kDa. This review will also explore some new observations regarding the generation of central respiratory activity in the fetus, and suggests that the rhythm generator is a neuronal network in which the unit is a pacemaker-like cell uniquely responsive to CO2.
Authors:
H Rigatto
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Reproduction, fertility, and development     Volume:  8     ISSN:  1031-3613     ISO Abbreviation:  Reprod. Fertil. Dev.     Publication Date:  1996  
Date Detail:
Created Date:  1996-11-14     Completed Date:  1996-11-14     Revised Date:  2005-11-16    
Medline Journal Info:
Nlm Unique ID:  8907465     Medline TA:  Reprod Fertil Dev     Country:  AUSTRALIA    
Other Details:
Languages:  eng     Pagination:  23-33     Citation Subset:  IM    
Affiliation:
University of Manitoba, Winnipeg, Canada.
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MeSH Terms
Descriptor/Qualifier:
Animals
Brain / embryology,  physiology
Carbon Dioxide / pharmacology
Embryonic and Fetal Development / physiology
Humans
Neurons / physiology
Oxygen / pharmacology
Respiration / drug effects,  physiology*
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen

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


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