 | This articlemay be too technical for most readers to understand. Pleasehelp improve it tomake it understandable to non-experts, without removing the technical details.(March 2025) (Learn how and when to remove this message) |
_effect.png)
Vascular permeability, often in the form ofcapillary permeability ormicrovascular permeability, characterizes thepermeability of ablood vessel wall–in other words, the blood vessel wall's capacity to allow for the flow of smallmolecules (such as drugs,nutrients, water, orions) or even wholecells (such aslymphocytes on their way to a site ofinflammation) in and out of the vessel.Blood vessel walls are lined by a single layer ofendothelial cells. The gaps between endothelial cells (cell junctions) are strictly regulated depending on the type andphysiological state of thetissue.[1][2][3][4]
There are several techniques to measure vascular permeability to certain molecules. For instance, thecannulation of a singlemicrovessel with amicropipette: the microvessel is perfused with a certain pressure, occluded downstream, and then the velocity of some cells will be related to the permeability.[5][6] Another technique uses multiphoton fluorescenceintravital microscopy through which the flow is related to fluorescence intensity and the permeability is estimated from the Patlak transformation.[7][clarification needed]
An example of increased vascular permeability is in theinitial lesion of periodontal disease, in which thegingival plexus becomes engorged anddilated, allowing large numbers ofneutrophils toextravasate and appear within thejunctional epithelium and underlyingconnective tissue.[8]