Document Detail


The regulation of transplacental cortisol-cortisone metabolism by estrogen in pregnant baboons.
MedLine Citation:
PMID:  3335215     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The present study tests the hypothesis that estrogen regulates the alteration in baboon placental cortisol (F)/cortisone (E) interconversion from preferential reduction (E----F) at midgestation to oxidation (F----E) near term. Five pregnant baboons (Papio anubis) received increasing numbers of 50-mg implants of androstenedione inserted sc at 8-day intervals between days 70 and 100 of gestation (term = day 184) to elevate the production of estrogen. Five animals served as controls at midgestation and received implants containing no steroid, while four baboons were studied near term between days 164-170 of gestation. All animals were bled from a maternal saphenous vein at 2-day intervals, and the serum was assayed for estradiol. On days 100 or 170 of gestation, transuterofetoplacental corticosteroid dynamics were determined by the constant infusion method. Baboons were anesthetized with ketamine and halothane-nitrous oxide and a constant infusion of [3H]F/[14C]E initiated via a maternal saphenous vein. At 60 min, animals were laparotomized and at 70, 80, and 90 min, blood samples were obtained from right and left uterine veins and from a maternal saphenous vein. At 95 min, an incision was made in the uterus, and blood samples were obtained from the umbilical vein and artery. Radiolabeled F and E were extracted from serum and purified by paper chromatography. Maternal serum E2 concentrations (nanograms per ml; mean +/- SE) were greater (P less than 0.01) between days 94 and 100 of gestation in androstenedione-treated baboons (2.4 +/- 0.3) than in untreated animals at midgestation (0.7 +/- 0.2), but lower than those near term (4.5 +/- 1.0). On day 100 of gestation, conversion of E to F across the uterus in control animals (30%) was similar to that of the reverse reaction (23%). In androstenedione-treated baboons at midgestation the conversion of E----F (8%) was lower (P less than 0.05) than the oxidation of F----E (27%) and not different from that in untreated baboons at term (E----F = 13%; F----E = 28%). The dominance of transuterofetoplacental conversion of F----E over the conversion of E----F in term and in androstenedione-treated animals at midgestation was maintained when transfer constants were corrected for fetal metabolic contributions. We conclude that the increase in placental estrogen production induced by androstenedione administration at midgestation alters the pattern of transuterofetoplacental F-E metabolism, supporting the hypothesis that estrogen regulates placental corticosteroid metabolism.
Authors:
G J Pepe; B J Waddell; S J Stahl; E D Albrecht
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Endocrinology     Volume:  122     ISSN:  0013-7227     ISO Abbreviation:  Endocrinology     Publication Date:  1988 Jan 
Date Detail:
Created Date:  1988-02-03     Completed Date:  1988-02-03     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0375040     Medline TA:  Endocrinology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  78-83     Citation Subset:  AIM; IM    
Affiliation:
Department of Physiology, Eastern Virginia Medical School, Norfolk 23507.
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MeSH Terms
Descriptor/Qualifier:
Androstenedione / pharmacology*
Animals
Cortisone / blood*
Drug Implants
Estradiol / blood*
Female
Hydrocortisone / blood*
Maternal-Fetal Exchange* / drug effects
Papio / blood*
Placenta / metabolism*
Pregnancy
Reference Values
Grant Support
ID/Acronym/Agency:
HD-13294/HD/NICHD NIH HHS
Chemical
Reg. No./Substance:
0/Drug Implants; 50-23-7/Hydrocortisone; 50-28-2/Estradiol; 53-06-5/Cortisone; 63-05-8/Androstenedione

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


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