A murine model of ex vivo angiogenesis using aortic disks grown in fibrin clot

The rat aortic ring model is well utilized for evaluation of angiogenesis. We report here an alternative assay employing an ex vivo mouse aorta angiogenesis model that can be extensively manipulated and serially evaluated using digital-assisted image analysis. Mouse aortas were harvested, cut into 2-mm disks, and cultured in fibrin matrix with growth media. Radial vascular outgrowths arose from the cut edge of the aortic disk and were digitally photographed and serially quantified. A variety of culture conditions were evaluated to determine their ability to alter angiogenesis in this model. Vessel outgrowth became apparent on day 3 and continued through day 10 with linear growth occurring between days 3 and 6. Increasing concentrations of serum from 0% to 40% resulted in stimulation of angiogenesis after day 3. Suramin and endostatin dramatically inhibited angiogenesis, which was more profound when applied at day 0 than when linear growth could be identified (day 3). Cells isolated from vessel outgrowths were predominantly endothelial in origin by immunocytochemistry and FACS analysis. We demonstrate that angiogenesis in an ex vivo murine model can be easily quantified using digital image analysis, responds appropriately to stimulation and inhibition, and exhibits differential results based on time of inhibitor administration. Antiangiogenic agents may be most effective if administered before development of accelerated vessel growth.