Angiogenesis, the sprouting of blood vessels from pre-existing vasculature, is associated with both natural and pathological processes. Here we demonstrate an aortic ring assay that allows angiogenic potentiators and inhibitors to be directly added to aortic rings in culture. Sprouting and neovessel outgrowth can be determined by inspecting the aortic rings over a period of 6-12 days.
One day before the experiment:
Day of the experiment:
Notes:
Aortic ring assay is a beneficial tool on the way to evaluate angiogenic as well as anti-angiogenic factors. The vessels that grow out from aortic rings recruit smooth muscle cells and pericytes to associate with the endothelial cell tube, meaning that they are anatomically similar to neovessels in vivo. Furthermore, the mouse aortic ring assay holds the advantage of the vast array of transgenic tools available for this species. Yet, there are several disadvantages to the aortic ring assay. First, vessels outgrowth in vivo occurs from microvessels and not from major vessels such as the aorta. Second, inconsistency in the handling of the rings and the amount of surrounding tissue remaining on the vessel can influence vessel outgrowth. Rings from different aortas or different mice’s ages and strains can also interfere with the angiogenic responses. And lastly, Angiogenic vessel outgrowth occurs in three dimensions, which makes it non-ideal to photograph and quantify. Taken together, when performed with sufficient internal controls and with multiple repeats, this assay is relatively simple, non-expensive, highly informative and significantly superior to endothelial cultures in its biological complexity and relevance.