Document Detail


Androgens and masculinization of genitalia in the spotted hyaena (Crocuta crocuta). 1. Urogenital morphology and placental androgen production during fetal life.
MedLine Citation:
PMID:  9713383     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
According to common understanding of sexual differentiation, the formation and development of a penile clitoris in female spotted hyaenas requires the presence of naturally circulating androgens during fetal life. The purpose of the present study was to determine potential source(s) of such fetal androgens by investigating the timing of urogenital development and placental production of androgen during early and mid-gestation. Fetuses determined to be female by molecular techniques (lack of SRY gene) at days 33 and 48 of gestation had undifferentiated gonads, but the clitoris was already 'masculinized' and was generally similar to the phallus of a 50-day-old male fetus. Wolffian and Müllerian ducts terminated at the urogenital sinus in both sexes and a urethra was present along the entire length of the clitoris and penis. The adrenal gland was large and histologically differentiated at 33 days. Steroid gradients across the uterus (a drop in delta 4-androstenedione, with increases in oestrogen and androgen), and high androstenedione in ovarian veins indicated that ovarian androstenedione was metabolized and secreted as testosterone by the placenta throughout gestation. In vitro, whole or homogenized placentae at days 48 and 58 of gestation (110 days total) metabolized radiolabelled androstenedione into testosterone and oestradiol; the specific enzymatic activity of early placental tissues was higher than at later stages. A human placental homogenate had higher aromatase activity but did not produce testosterone unless aromatase was inhibited. Infusion of labelled androstenedione into the uterine arteries of hyaenas demonstrated the conversion of this substrate into testosterone and oestradiol and their secretion into the fetal circulation. Evidently, androgen is produced by the placenta and secreted into the fetal circulation from early in pregnancy when masculinization is first evident, before differentiation of the fetal ovary.
Authors:
P Licht; T Hayes; P Tsai; G Cunha; H Kim; M Golbus; S Hayward; M C Martin; R B Jaffe; S E Glickman
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of reproduction and fertility     Volume:  113     ISSN:  0022-4251     ISO Abbreviation:  J. Reprod. Fertil.     Publication Date:  1998 May 
Date Detail:
Created Date:  1998-09-01     Completed Date:  1998-09-01     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0376367     Medline TA:  J Reprod Fertil     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  105-16     Citation Subset:  IM    
Affiliation:
Department of Integrative Biology, University of California at Berkeley 94720, USA.
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MeSH Terms
Descriptor/Qualifier:
Androgens / physiology*
Androstenedione / metabolism
Animals
Carnivora / embryology*
Clitoris / embryology
Female
Gestational Age
Male
Mesonephros / anatomy & histology
Mullerian Ducts / anatomy & histology
Ovary / embryology
Placenta / metabolism*
Sex Differentiation / physiology*
Testis / embryology
Urethra / embryology
Urogenital System / embryology*
Wolffian Ducts / anatomy & histology
Grant Support
ID/Acronym/Agency:
MH-39917/MH/NIMH NIH HHS
Chemical
Reg. No./Substance:
0/Androgens; 63-05-8/Androstenedione

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


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