The effect of KRX-725 and S1P on aortic ring sprouting. (A) Aortic rings from C57BL/6 mice embedded in collagen matrix were exposed to KRX-725 (10 and 20 μM), S1P (100 nM), and vehicle (0.1% DMSO) for 9 days. The rings were then fixed and stained with crystal violet (0.02%) to illustrate sprouting. Representative micrographs of each arm of the experiment are shown. Micrographs were taken under × 4 objective. (B) Statistical morphometric analysis of the sprout length and thickness of 4 repeats from panel A. Mean ± SEM is presented relative to the control rings (100%), treated with vehicle. * indicates statistical significance (P < .05, Wilcoxon test) of treatment versus control.