Endothelial Permeability
 
 
Actin filaments form the main component of stress fibers that compose the tethering system within endothelial cells. These fibers radiate outward from the perinuclear region and often are connected to the plasma membrane in prominent regions called focal contacts that connect to extracellular matrix.  Pools of monomeric (G-) actin (green in the image to the right) exist in dynamic equilibrium with filamentous (F-) actin (Red in the image) as the cell responds to changes in environmental stimuli or changes in functional demands.  Changes in actin equilibrium may affect the cells ability to adhere to each other and/or the substratum.
 
 
    Taylor et al 2003     Eiselein et al 2007     Learn about Endothelial cell junctions   http://livepage.apple.com/http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17259442Regulation%20of%20Endothelial%20Perm.htmlhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12499124shapeimage_1_link_0shapeimage_1_link_1shapeimage_1_link_2
The Actin Cytoskeleton
Confocal Microscopy Image of Bovine Pulmonary Endothelial Cells Stained for F and G Actin