(A) Serum collected from sham operated (n=17) and HI rats immediately 0 h (n=5), 3 h (n=12), 6 h (n=14), 12 h (n=12), 24 h (n=11), and 48 h (n=15) h after exposure to HI. Mean ± SD, *P<0.05, ANOVA, Fisher LSD. (B) Representative Western immunoblots for β-Actin (43KD) and HMGB1 (28 kD) shown for the internal control protein (IC), in Sham control, and 3, 12 and 48 h after HI. Total protein extracted from ipsilateral-HI cerebral cortical hemisphere from rat brain of sham treated, 3, 12, and 48 h after exposure to HI (each group: n=5). Total HMGB1 expression in rat brain, plotted as ratio to internal control (IC). Mean ± SD, * P<0.05, ANOVA, Fisher LSD.