title: The bile acid synthesis pathway is present and functional in the human ovary.
abstract: BACKGROUND
  Bile acids, end products of the pathway for cholesterol elimination, are required for dietary lipid and fat-soluble vitamin absorption and maintain the balance between cholesterol synthesis in the liver and cholesterol excretion. They are composed of a steroid structure and are primarily made in the liver by the oxidation of cholesterol. Cholesterol is also highly abundant in the human ovarian follicle, where it is used in the formation of the sex steroids.
  
  
  RESULTS
  Here we describe for the first time evidence that all aspects of the bile acid synthesis pathway are present in the human ovarian follicle, including the enzymes in both the classical and alternative pathways, the nuclear receptors known to regulate the pathway, and the end product bile acids. Furthermore, we provide functional evidence that bile acids are produced by the human follicular granulosa cells in response to cholesterol presence in the culture media.
  
  
  CONCLUSIONS
  These findings establish a novel pathway present in the human ovarian follicle that has the capacity to compete directly with sex steroid synthesis.
authors.affiliation: Division of Reproductive Endocrinology & Infertility, Department of Obstetrics & Gynecology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Laura P
authors.initials: LP
authors.lastname: Smith
authors.forename: Maik
authors.initials: M
authors.lastname: Nierstenhoefer
authors.forename: Sang Wook
authors.initials: SW
authors.lastname: Yoo
authors.forename: Alan S
authors.initials: AS
authors.lastname: Penzias
authors.forename: Edda
authors.initials: E
authors.lastname: Tobiasch
authors.forename: Anny
authors.initials: A
authors.lastname: Usheva
mesh_terms: D001647:Bile Acids and Salts / Q000378:metabolism*; D001692:Biological Transport; D002784:Cholesterol / Q000737:chemistry* / Q000378:metabolism*; D003470:Culture Media / Q000378:metabolism; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008954:Models, Biological; D006080:Ovarian Follicle / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism* / Q000502:physiology*; D010100:Oxygen / Q000737:chemistry*
chemical_list: D001647:Bile Acids and Salts; D003470:Culture Media; D002784:Cholesterol; D010100:Oxygen