a): Confocal microscopy images of ischemic middle cerebral artery (MCA), cerebral microvessels (Mic.V), and surrounding brain tissue (Brain) immunofluorescently labeled for iNOS (A-E), IL-6 (F-J), IL-1ß (K-O) and TNF-α (P-T). Images represent the vehicle control group (A, P), MCAO plus vehicle group (B, Q), MCAO plus U0126 starting at 0 hours (C, R), 6 hours (D, S), or 12 hours (E, T). There were significant increases in iNOS, IL-6, IL-1ß and TNF-α protein levels in the smooth muscle cell layer of ischemic vessels (MCA and Mic.V) as compared with vessels from the vehicle control group. Treatment with U0126 starting at zero and 6 hours, but not 12 hours, after occlusion prevented the increase in expression of these proteins. There was a slight increase in iNOS protein expression in ischemic brain tissue around vessels as compared to control and U0126-treated brain tissue. Scale bar, 50 μm. b): Bar graphs showing semi-quantification of fluorescence intensity for iNOS, IL-6, IL-1ß and TNF-α in MCA. There were significant increases in the expression of these proteins in MCAO animals as compared to control animals; this increase was prevented with U0126 treatment starting at zero and 6 hours, but not 12 hours, post MCAO. Data are presented as the mean percentage relative to control ± SEM.; n = 5. *P < 0.05, significant difference between control and treated at 12 h, **P < 0.01 significant difference between control groups and MCAO, #P < 0.05 and ##P < 0.01 significant difference between treatment groups (0 h and 6 h) and MCAO groups.