Document Detail

Aberrant maternal behaviour in mice treated with a progesterone receptor antagonist during pregnancy.
MedLine Citation:
PMID:  7616171     Owner:  NLM     Status:  MEDLINE    
The rapid onset of normal maternal behaviour after parturition in mice, consisting of cleaning, warming, feeding and protection of offspring, is primed by oestrogen, progesterone and oxytocin. Previous studies showed that passive transfer of monoclonal antibodies against progesterone significantly increases the incidence of maternal rejection of pups. To test the hypothesis that aberrant maternal behaviour is due to partial progesterone withdrawal leading to hormonal imbalance during late pregnancy, maternal rejection was assessed following treatment with a progesterone receptor antagonist. Mifepristone (RU486) was given subcutaneously on either day 2 (100 micrograms) or day 17 (50 micrograms) of pregnancy, or on the first day of lactation (100 micrograms). Maternal behaviour was monitored twice daily for the first 6 days of lactation and pup rejection recorded for a further 15 days. Maternal rejection was significantly greater after mifepristone administration on either day 2 or day 17 (28.6% and 38.3%) compared with controls (11.1% and 5.2% respectively). Rejection was negligible in both treated and control groups if mifepristone was given after parturition. When mothers were treated at day 17, the length of the latent period before pups were retrieved and returned to the nest was markedly increased in mifepristone-treated mothers (46.3 s) compared with controls (4.4 s) though the effect was transient. The results indicate that mifepristone interferes with the hormonal priming mechanism(s) necessary for the onset of normal maternal behaviour by a receptor-mediated effect. The similarity of the present results and those obtained with anti-progesterone antibodies implies that receptor antagonism or antibody scavenging of progesterone influence a common central nervous mechanism that is essential for the normal priming process.
M W Wang; D L Crombie; J S Hayes; R B Heap
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of endocrinology     Volume:  145     ISSN:  0022-0795     ISO Abbreviation:  J. Endocrinol.     Publication Date:  1995 May 
Date Detail:
Created Date:  1995-08-18     Completed Date:  1995-08-18     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  0375363     Medline TA:  J Endocrinol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  371-7     Citation Subset:  IM    
Ligand Pharmaceuticals Inc., La Jolla, California 92037, USA.
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MeSH Terms
Lactation / drug effects
Maternal Behavior / drug effects*
Mice, Inbred BALB C
Mifepristone / pharmacology*
Pregnancy, Animal / drug effects*
Receptors, Progesterone / antagonists & inhibitors*
Reg. No./Substance:
0/Receptors, Progesterone; 84371-65-3/Mifepristone

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

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