Not only do ECs produce ANG2 by transcriptional activation, but they also store it in specialized endothelial storage
granules, the so-called Weibel–Palade bodies, in which it colocalizes with the haemostasis-regulating glycoprotein
von Willebrand Factor (vwF)104. A secretagogue (a substance that induces the secretion of another), such
as thrombin or vasopressin, can liberate weibel–Palade body stores in seconds to minutes, making their content
available to control rapid EC responses, such as permeability, coagulation and inflammation. Variations in ANG2 storage in different vascular beds in vivo might ultimately account for the degree of responsiveness or refractoriness of a specific vascular bed to inflammatory or angiogenic cytokines. For example, significant ANG2 stores in the vascular endothelium can be detected in microvessels of the brain, whereas ANG2 that is stored in weibel–Palade bodies was hardly detectable in skeletal muscle or the myocardial vasculature26.