Ultrastructure of cellular components of human trophoblasts during early pregnancy.
Two cell types, the cyto- and syncytio-trophoblasts, were identified in human chorionic villi of 6-10 weeks' gestation. The intracellular organization of these cells was examined. Ultrathin sections of small pieces of chorionic villi revealed the presence of a multinucleate syncytiotrophoblastic layer, whose surface was covered with microvilli. The cytotrophoblasts, however, had a single large nucleus with a prominent nucleolus. An interesting feature of the basement membrane of these cells was the presence of aggregates of dark granules in samples of the earlier gestational age (6-8 weeks) and granular bodies having a dense outer ring and a translucent inner ring with a lucid central area in samples of 8-10 weeks' gestation. Both types of granules are mineralized and are assumed to perform a buffering role for maintaining the neutrality of the layer.
Jaggi
M
M
Division of Endocrinology, Central Drug Research Institute, Lucknow, India.
Mehrotra
P K
PK
Maitra
S C
SC
Agarwal
S L
SL
Das
K
K
Kamboj
V P
VP
D002467:Cell Nucleus / Q000648:ultrastructure; D002824:Chorionic Villi / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008854:Microscopy, Electron; D008871:Microvilli / Q000648:ultrastructure; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D014327:Trophoblasts / Q000648:ultrastructure*; D014617:Vacuoles / Q000648:ultrastructure