title: Morphology of the mitochondria and endoplasmic reticula of chorion laeve cytotrophoblasts: their resemblance to villous syncytiotrophoblasts rather than villous cytotrophoblasts.
abstract: We examined the morphological features of the mitochondria and endoplasmic reticula of chorion laeve cytotrophoblasts from term human fetal membranes, and compared them with those of syncytiotrophoblasts and cytotrophoblasts from human placental villi. Ultrastructural enzyme histochemistry of cytochrome c oxidase and glucose-6-phosphatase were used as cytochemical markers for these intracellular organelles. Chorion laeve cytotrophoblasts possessed abundant endoplasmic reticula, and small mitochondria with a few cristae, which were characteristic of villous syncytiotrophoblasts rather than villous cytotrophoblasts. As for these organellar structures, statistical analysis confirmed similarities between chorion laeve cytotrophoblasts and villous syncytiotrophoblasts, but significant differences between laeve cytotrophoblasts and villous cytotrophoblasts. Though these two cytotrophoblasts originated from one common cell in early placental development, they exhibited quite different organellar morphology during placental/chorioamniotic differentiation. Considering previous data, we concluded that chorion laeve cytotrophoblasts were metabolically active cells, similar to villous syncytiotrophoblasts, performing many functions in fetal membrane physiology.
authors.affiliation: Department of Obstetrics and Gynecology, Jichi Medical School, Minamikawachi-machi 3311-1, Kawachi-gun, Tochigi 329-0498, Japan. matsushi@jichi.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Matsubara
authors.forename: T
authors.initials: T
authors.lastname: Takayama
authors.forename: R
authors.initials: R
authors.lastname: Iwasaki
authors.forename: H
authors.initials: H
authors.lastname: Minakami
authors.forename: T
authors.initials: T
authors.lastname: Takizawa
authors.forename: I
authors.initials: I
authors.lastname: Sato
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002823:Chorion / Q000166:cytology / Q000196:embryology; D002824:Chorionic Villi / Q000648:ultrastructure*; D003576:Electron Transport Complex IV / Q000032:analysis*; D004721:Endoplasmic Reticulum / Q000648:ultrastructure*; D005260:Female; D005952:Glucose-6-Phosphatase / Q000032:analysis*; D006651:Histocytochemistry / Q000379:methods; D006801:Humans; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure*; D011247:Pregnancy; D014327:Trophoblasts / Q000166:cytology / Q000648:ultrastructure*
chemical_list: D015415:Biomarkers; D003576:Electron Transport Complex IV; D005952:Glucose-6-Phosphatase