Detailed structure of sprouts induced by KRX-725. (A) Sprouts induced by KRX-725 (20 μM) or VEGF (25 ng/mL) in Sprague-Dawley rat aortic rings. After 10 days, the rings were fixed with formaldehyde, stained with crystal violet (0.02%), and examined microscopically. Representative micrographs of 6 repeats are depicted. (B) H&E staining of cross-section (5 μm) of paraffin-blocked BALB/c aortic rings incubated with KRX-725 (20 μM, 7 days). Micrographs were taken under × 40 objective. L indicates lumen; AO, aortic ring.