title: Placentation in the African elephant (Loxodonta africana). V: the trophoblast secretes placental lactogen.
abstract: OBJECTIVE
  To determine if elephant placenta secretes a lactogenic hormone which may function as the principal luteotrophin to maintain ovarian luteal function throughout gestation.
  
  
  METHODS
  To label biopsies of endometrium and placenta recovered from African elephant culled professionally throughout gestation with an anti-human prolactin polyclonal antibody in a conventional immunocytochemical staining technique.
  
  
  RESULTS
  All trophoblast cells covering the placental villi and forming 'plugs' in the apical endometrial glands stained strongly and precisely with the anti-human prolactin antiserum throughout gestation.
  
  
  CONCLUSIONS
  Elephant trophoblast secretes a placental lactogen (elPL) which may stimulate both the development and secretory function of the large accessory corpora lutea of elephant pregnancy and provide the mitogenic stimulus for placental differentiation and development.
authors.affiliation: Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, Fuchu, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Taya
authors.forename: G
authors.initials: G
authors.lastname: Watanabe
authors.forename: F J
authors.initials: FJ
authors.lastname: Stansfield
authors.forename: W R
authors.initials: WR
authors.lastname: Allen
mesh_terms: D000818:Animals; D004606:Elephants / Q000502:physiology*; D005260:Female; D006801:Humans; D010928:Placental Lactogen / Q000378:metabolism*; D010929:Placentation; D011247:Pregnancy; D011388:Prolactin / Q000276:immunology; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D011388:Prolactin; D010928:Placental Lactogen