Measurement of albumin permeability across endothelial monolayers in vitro

J Appl Physiol (1985). 1987 Mar;62(3):1076-83. doi: 10.1152/jappl.1987.62.3.1076.


We have developed an experimental system to measure the permeability of the cultured endothelial monolayer. The luminal-to-abluminal flux of 125I-albumin across cultured pulmonary endothelium was expressed as a clearance rate equal to the permeability-surface area product. After clearance rate measurement for a 30-min base-line period, a test agent was added to the luminal side, and the clearance rate was remeasured during a 30-min experimental period. In control studies the base-line clearance rate was 0.343 +/- 0.017 microliter/min. After correction for the diffusional resistances of the filter and unstirred layers, the calculated permeability of the endothelial monolayer was 1.2 X 10(-5) cm/s. When culture medium was the test agent, the experimental clearance rate was unchanged from the base-line value. After addition of 4 mM oleic acid to the luminal chamber, the clearance rate was 0.528 +/- 0.017 microliter/min compared with a base-line value of 0.330 +/- 0.008 microliter/min (P less than 0.005). This method allows the calculation of endothelial permeability with correction for unstirred layers and the use of each monolayer as its own control.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Cell Membrane Permeability*
  • Cells, Cultured
  • Endothelium / cytology
  • Endothelium / physiology*
  • Endothelium / ultrastructure
  • Kinetics
  • Microscopy, Electron
  • Models, Biological
  • Serum Albumin


  • Serum Albumin