Weibel–Palade body

Weibel- Palade bodies ( WPK ) are about 0.1 × 2 microns large cell organelles which are predominantly kernnah in the cytoplasm of cells of the blood vessel inner walls. In its tubular internal structure save the von Willebrand factor, which promotes blood clotting, interleukin- 8, which attracts white blood cells, the transmembrane protein P -selectin, which binds selbige and angiopoietin -2, mobilizes stem cells. By physiological agonists such as thrombin, histamine, or uric acid, which results from insufficient supply of tissues with oxygen ( ischemia), within seconds, a distribution of these substances can be induced in the direct cell environment. In the presence of an inflammatory response, the number of Weibel- Palade bodies almost doubled.

In a direct representation of the cell organelles using a transmission electron microscope usually show only a few small incisions of the Weibel- Palade bodies. However, Via immunofluorescence can be easily represented if they are labeled with fluorescent antibodies highly specific for its intense expression of factor VIII antigen, these characteristic in shape and size vesicles.