Document Detail


Corticosterone transfer and metabolism in the dually perfused rat placenta: effect of 11beta-hydroxysteroid dehydrogenase type 2.
MedLine Citation:
PMID:  16338462     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Although rat is the most widely used model of glucocorticoid programming of the fetus, the role of rat placental 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) in the transplacental pharmacokinetics of the naturally occurring glucocorticoid, corticosterone, has not yet been fully elucidated. In this study, expression of 11beta-HSD2 in the rat placenta on two different gestation days (16 and 22) was examined using quantitative RT-PCR and Western blotting, and dually perfused rat term placenta was employed to evaluate its functional capacity to transfer and metabolize corticosterone. Marked decrease in placental expression of 11beta-HSD2 toward term was observed on both mRNA and protein levels. In perfusion studies, increasing maternal corticosterone concentration from 3 to 200 nM resulted in the fall of 11beta-HSD2 conversion capacity from 64.3 to 16.3%, respectively. Enzyme saturation occurred at about 50 nM substrate concentration. When delivering corticosterone (3 or 100 nM) from the fetal side, a similar decline of 11beta-HSD2 conversion capacity was observed (66.5% and 48.5%, respectively). Addition of carbenoxolone (10 or 100 microM), a non-specific 11beta-HSD inhibitor, to maternal perfusate decreased conversion capacity from 66.7 to 12.6 or 8.1%, respectively. Similarly potent inhibitory effect was observed in feto-maternal studies. Neither saturation nor inhibition of 11beta-HSD2 was associated with transformation of corticosterone in metabolites other than 11-dehydrocorticosterone. These data suggest that 11beta-HSD2 is the principal enzyme controlling transplacental passage of corticosterone in rats and is able to eliminate corticosterone in both maternal and fetal circulations.
Authors:
F Staud; K Mazancová; I Miksík; P Pávek; Z Fendrich; J Pácha
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Placenta     Volume:  27     ISSN:  0143-4004     ISO Abbreviation:  Placenta     Publication Date:    2006 Feb-Mar
Date Detail:
Created Date:  2005-12-12     Completed Date:  2006-03-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8006349     Medline TA:  Placenta     Country:  England    
Other Details:
Languages:  eng     Pagination:  171-80     Citation Subset:  IM    
Affiliation:
Department of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, Hradec Králové CZ-500 05, Czech Republic. staud@faf.cuni.cz
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MeSH Terms
Descriptor/Qualifier:
11-beta-Hydroxysteroid Dehydrogenase Type 2 / antagonists & inhibitors,  genetics,  metabolism*
Animals
Biological Transport
Carbenoxolone / pharmacology
Corticosterone / metabolism*
Female
Perfusion
Placenta / enzymology,  metabolism,  physiology*
Pregnancy / metabolism*
Rats
Chemical
Reg. No./Substance:
50-22-6/Corticosterone; 5697-56-3/Carbenoxolone; EC 1.1.1.146/11-beta-Hydroxysteroid Dehydrogenase Type 2

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


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