Document Detail

Indicators of delayed maturation of rat heart treated prenatally with dexamethasone.
MedLine Citation:
PMID:  9262213     Owner:  NLM     Status:  MEDLINE    
We investigated the effects of prenatal dexamethasone treatment on indicators of cardiac maturation: heart weight/body weight ratios, myosin heavy chain (MHC) expression, cell proliferation, and extracellular matrix. We administered dexamethasone, a synthetic glucocorticoid (approximately 48 microg/d, 3-wk slow release pellets), to pregnant rats (n = 8) beginning at 17 d postconception. Control dams were unmanipulated (n = 8). After approximately 4-5 d of dexamethasone exposure, hearts were collected from neonatal rats (12-24 h after birth). The prenatal dexamethasone treatment produced smaller pups with larger heart/body weight ratios, accompanied by a higher proliferative index and a reduction in extracellular matrix in the ventricles (with lowest values in the septal region) compared with control pups. We also report that, although there were no sex differences in body mass or heart and heart/body weight ratios, females had a greater proportion of cells synthesizing DNA in the heart. In addition, ventricles of male pups treated with dexamethasone contained lower levels of alpha-MHC mRNA, as reflected in a sex by treatment interaction. The changes in each parameter are consistent with delayed maturation. Our findings suggest that exposure to excess glucocorticoids in utero can affect cardiac development in potentially detrimental ways and that assessment of cardiac function should be closely monitored when such circumstances arise.
A Torres; W W Belser; P K Umeda; D Tucker
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Pediatric research     Volume:  42     ISSN:  0031-3998     ISO Abbreviation:  Pediatr. Res.     Publication Date:  1997 Aug 
Date Detail:
Created Date:  1997-10-02     Completed Date:  1997-10-02     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0100714     Medline TA:  Pediatr Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  139-44     Citation Subset:  IM    
Department of Psychology, University of Alabama in Huntsville, 35899, USA.
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MeSH Terms
Body Weight / drug effects
Cell Count / drug effects
DNA / biosynthesis
Dexamethasone / toxicity*
Extracellular Matrix / drug effects
Fetal Organ Maturity*
Glucocorticoids / toxicity*
Heart / drug effects*,  growth & development
Major Histocompatibility Complex / genetics
Organ Size / drug effects
Prenatal Exposure Delayed Effects*
RNA, Messenger / biosynthesis
Rats, Sprague-Dawley
Grant Support
Reg. No./Substance:
0/Glucocorticoids; 0/RNA, Messenger; 50-02-2/Dexamethasone; 9007-49-2/DNA

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

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