Fig. 3

Fig. 3

Aortic ring assay of angiogenesis. a Serum-free collagen gel culture of rat aorta (asterisk) photographed at day 6 (microvessels marked by arrowheads). b Aortic culture treated with VEGF (5 ng/ml) shows increased number of microvessels (day 6). c Electron micrograph of aorta-derived microvessel with polarized endothelium (E), patent lumen (L), and surrounding pericytes (P); endothelial tight junctions are marked by arrows. d Phase-contrast micrograph of microvessel composed of an inner core of endothelial cells and surrounding pericytes (white arrowheads). e Pericytes highlighted with immunoperoxidase stain for NG2. f Immunofluorescent image of aorta-derived macrophages stained for CD45; an isolectin B4 (IB4)-stained endothelial sprout is visible in the background. g Confocal image of microvessel double stained for endothelial cells (IB4) and pericytes (alpha smooth muscle actin, αSMA). Magnification bars = 500 μm (a, b), 5 μm (c), 50 μm (d–g)