Figure 6-4039.

Paired bright and dark field photomicrographs showing vascular endothelial growth factor 2 (VEGFR-2) gene expression in 3-μm thick paraffin sections of retinas from sham and ROP rats treated with STI571. Sections are counterstained with hematoxylin and eosin. The paired bright and dark field panels on the left show sham groups and the paired bright and dark field panels on the right are ROP groups. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; ONL, outer nuclear layer; RPE, retinal pigment epithelium. Original magnification ×120. In all groups, VEGF mRNA is observed in the GCL, IPL and INL and the RPE. Untreated sham (A and a) and sham + 50 mg/kg/day (B and b) are similar with mRNA most notable over the INL. Sham + 100 mg/kg/day STI571 (C and c) shows an increase in mRNA in the inner retina compared to sham groups. ROP (D and d), shows intense VEGF mRNA in the inner retina and particularly the INL. ROP + 50 mg/kg/day STI571 (E and e) shows increased signal in the inner retina compared to untreated ROP which is further increased in the ROP + 100 mg/kg/day STI571 group (F and f). Results are shown graphically. Values are means ± SEM. N = 6 to 8 rats per group. *, P < 0.0001 compared to all groups except sham + 50 mg/kg/day STI571. , P < 0.0001 compared to all groups except untreated sham. ^†, P < 0.0001 compared to sham groups and ROP + 100 mg/kg/day STI571. ^‡, P < 0.05 compared to ROP + 50 mg/kg/day STI571. ^§, P < 0.001 compared to ROP + 100 mg/kg/day STI571. ^§§, P < 0.0001 compared to all groups.