Document Detail

In vitro conversion of pregnenolone to progesterone by term human fetal membranes.
MedLine Citation:
PMID:  7355943     Owner:  NLM     Status:  MEDLINE    
The conversion of pregnenolone to progesterone by homogenates of term human fetal membranes (38 to 40 weeks' gestation) was quantitated prior to and after labor. Chorion pars reflexa obtained after spontaneous labor by vaginal delivery was more active than that obtained prior to labor by elective cesarean section (p less than 0.05). With homogenates of amnion pars reflexa (n = 18), and pars placentaris (n = 18) obtained prior to labor no conversion or pregnenolone to progesterone was detected. In contrast, in amnion pars reflexa obtained after labor the reaction was detected in five of the 13 tissues examined and was significantly different from tissues obtained prior to labor (p less than 0.01). However, the conversion by the amnion pars placentaris after labor was not significantly different from that to labor. Evidence for inhibition of the reaction in the amnion pars reflexa and pars placentaris obtained prior to labor was found when prolonged washing of these tissues (up to 5 hours) with isotonic KCl resulted in the conversion of pregnenolone to progesterone being easily detected. This study suggests that there may be "activation" of the conversion of pregnenolone to progesterone in fetal membranes during labor and indicates that considerable care should be taken in studying this and perhaps other reactions in fetal membranes as the mode of delivery, the preparation of tissue, and, in the case of the amnion, the area studied can affect the results obtained.
W Gibb; J C Lavoie; J Roux
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Publication Detail:
Type:  Comparative Study; In Vitro; Journal Article    
Journal Detail:
Title:  American journal of obstetrics and gynecology     Volume:  136     ISSN:  0002-9378     ISO Abbreviation:  Am. J. Obstet. Gynecol.     Publication Date:  1980 Mar 
Date Detail:
Created Date:  1980-04-23     Completed Date:  1980-04-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370476     Medline TA:  Am J Obstet Gynecol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  631-4     Citation Subset:  AIM; IM    
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MeSH Terms
Amnion / metabolism
Chorion / metabolism
Delivery, Obstetric
Extraembryonic Membranes / metabolism*
Pregnenolone / metabolism*
Progesterone / biosynthesis*
Reg. No./Substance:
145-13-1/Pregnenolone; 57-83-0/Progesterone

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

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