title: Unidirectional transport across cultured ovine amniotic epithelial cell monolayer.
abstract: OBJECTIVE
  To determine whether ovine amniotic cells in monolayer culture exhibit unidirectional transport.
  
  
  METHODS
  Permeability of (14)C-inulin was measured in two directions across ovine amniotic cells grown to confluence on cell culture inserts.
  
  
  RESULTS
  Permeability was 0.69 + 0.17 (SE) microl/min/cm(2) from the top of the insert where the cells were attached to the bottom and 0.11 + 0.02 microl/min/cm(2) in the reverse direction (P < 0.001). Permeability was similar in the two directions for chorionic cells and umbilical vein endothelial cells. Addition of vascular endothelial growth factor did not alter permeability.
  
  
  CONCLUSIONS
  Transcellular transport in ovine amniotic monolayers is directionally specific. The transport ratio of 6.2:1 for (14)C-inulin is comparable to the in vivo ratio of 4.7:1 for the ovine intramembranous pathway and is consistent with passive diffusion in both directions and vesicular transport in one direction across the monolayer at 5.2 times the rate of passive diffusion.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, Oregon 97210, USA.
authors.forename: Cecilia Y
authors.initials: CY
authors.lastname: Cheung
authors.forename: Robert A
authors.initials: RA
authors.lastname: Brace
mesh_terms: D000650:Amnion / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002250:Carbon Radioisotopes; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D004848:Epithelium / Q000378:metabolism / Q000502:physiology; D005260:Female; D007444:Inulin; D011247:Pregnancy; D034561:Sheep, Domestic
chemical_list: D002250:Carbon Radioisotopes; D007444:Inulin