Document Detail

Lack of short-term modulation of in vitro placental progesterone secretion in sheep.
MedLine Citation:
PMID:  3070536     Owner:  NLM     Status:  MEDLINE    
Experiments were performed in order to determine whether progesterone secretion in the ovine placenta can be short-term regulated. There was an increase in progesterone content per unit weight in ovine fetal cotyledons as gestation progressed: 17.0 +/- 4.7 ng/100 mg of wet tissue in ewes between 40 and 54 days of pregnancy (n = 7) and 70.7 +/- 18.8 (n = 9) between 100 and 118 days. At all stages of pregnancy, neither progesterone nor 20 alpha-dihydroprogesterone synthesis were significantly affected when fetal cotyledons were incubated for 3 h in the presence of LH, 8-Br-cAMP, GnRH agonist or GnRH antagonist. Addition of pregnenolone to the incubation medium increased progesterone secretion in a dose-dependent manner while addition of 25-hydroxycholesterol did not. These results suggest that the existent (basal) synthesis of progesterone reflects the maximal capacity of steroidogenesis through the cholesterol side-chain-cleavage system. In the presence of these precursors, LH, 8-Br-cAMP, the phorbol ester derivative PMA and calcium ionophore A23187 were not able to modify progesterone or 20 alpha-dihydroprogesterone synthesis. These results also suggest that LH or GnRH and the two signal mechanisms involved in their action, i.e. cAMP and Ca2+ sensitive-inositol phospholipid-dependent mechanisms are not implicated in the short-term regulation of progesterone synthesis in the ovine placenta.
M P de la Llosa-Hermier; M A Zongazo; J Martal; C Hermier
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Placenta     Volume:  9     ISSN:  0143-4004     ISO Abbreviation:  Placenta     Publication Date:    1988 Nov-Dec
Date Detail:
Created Date:  1989-04-26     Completed Date:  1989-04-26     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8006349     Medline TA:  Placenta     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  623-31     Citation Subset:  IM    
Laboratoire des Hormones Polypeptidiques, C.N.R.S., Gif-sur-Yvette, France.
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MeSH Terms
8-Bromo Cyclic Adenosine Monophosphate / pharmacology
Gonadotropin-Releasing Hormone / analogs & derivatives,  antagonists & inhibitors,  pharmacology
Hydroxycholesterols / metabolism
Luteinizing Hormone / pharmacology
Placenta / drug effects,  physiology*
Pregnenolone / metabolism
Progesterone / secretion*
Reg. No./Substance:
0/Hydroxycholesterols; 145-13-1/Pregnenolone; 2140-46-7/25-hydroxycholesterol; 23583-48-4/8-Bromo Cyclic Adenosine Monophosphate; 33515-09-2/Gonadotropin-Releasing Hormone; 51278-35-4/LHRH, Ala(6)-; 57-83-0/Progesterone; 64789-67-9/LHRH, Phe(2)-Pro(3)-Phe(6)-; 9002-67-9/Luteinizing Hormone

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

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