Time-dependent changes in the level of transduced 11R-HO-1 in BAs in vivo. Several hours (2, 6, 8, 24, and 48 hours) after protein injection, rat BAs were immunostained and observed under a fluorescent microscope (A). Fluorescence intensity was also analyzed using Scion image (B). Exposure time was identical within each experiment. Bars, 50 μm. BA, basilar artery; HO-1, heme-oxygenase-1.