Document Detail

Perinatal thermogenesis.
MedLine Citation:
PMID:  7493585     Owner:  NLM     Status:  MEDLINE    
The rapid initiation of thermogenesis is crucial for the survival of newborn infants. At birth the fetus must adapt to cooling, increased oxygenation and separation from the placenta. An experimental approach in the chronically instrumental fetal sheep of 'simulated birth in utero' allowed the evaluation of each of these stimuli sequentially. Cooling stimulated shivering, cardiovascular and endocrine responses but not nonshivering thermogenesis (NST). Ventilation of the cooled fetus with oxygen caused only modest NST which was not altered by an infusion of triiodothyronine. Occluding the umbilical cord was followed by a rapid substantial rise in NST which was maintained until the placental circulation was re-established. Thus the placenta is secreting factors into the fetal circulation which inhibit the ability of the brown adipose tissue to respond to either hormonal or neural stimuli. Placental prostaglandin E2 and probably adenosine are tonic inhibitors of thermogenesis in utero. Effective thermogenesis after birth requires the combination of separation from the placental inhibitors of lipolysis, increased oxygenation from breathing and the stimulation of cutaneous cold receptors.
T R Gunn; P D Gluckman
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Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Early human development     Volume:  42     ISSN:  0378-3782     ISO Abbreviation:  Early Hum. Dev.     Publication Date:  1995 Aug 
Date Detail:
Created Date:  1996-01-11     Completed Date:  1996-01-11     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  7708381     Medline TA:  Early Hum Dev     Country:  IRELAND    
Other Details:
Languages:  eng     Pagination:  169-83     Citation Subset:  IM    
Department of Paediatrics, School of Medicine, University of Auckland, New Zealand.
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MeSH Terms
Adenosine / physiology
Adipose Tissue, Brown / physiology
Animals, Newborn / physiology*
Body Temperature Regulation / drug effects,  physiology*
Cold Temperature
Dinoprostone / physiology
Fetus / blood supply,  physiology*
Oxygen / administration & dosage
Placenta / blood supply,  physiology
Sheep / embryology,  physiology
Reg. No./Substance:
363-24-6/Dinoprostone; 58-61-7/Adenosine; 7782-44-7/Oxygen

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

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