RESUMO
Existing methods to quantify angiogenesis range from image analysis of photographs to fluorescent microscopy. These methods are often time consuming and costly; they also may not detect capillaries if they are indistinct from the background of the image. We have developed a simple method based on the motion of blood to create an image that reveals the entire angiogenic vasculature. Two image analysis software programs were used separately to demonstrate the method. Using either ImageJ or Environment for Visualizing Images, we analyzed a video clip of regenerated tissue from the partially amputated caudal fin of a zebrafish (Danio rerio). The deviations among the frames in the video stack were calculated to reveal pixels where motion has occurred. The resulting image highlighted all vessels through which blood flowed and allowed for automatic quantification of the newly developed vasculature. Using this method, we quantified the angiogenic action of basic fibroblast growth factor and vascular endothelial growth factor, as well as suppression of angiogenesis by an inhibitor. In a preliminary study, we also found that it could be used to trace the developing vasculature in zebrafish embryos. Thus, motion-based angiogenesis analysis may provide an easy and accurate quantification of angiogenesis.