Release of interleukin-6 and keratinocyte-derived chemokine from the brain after middle cerebral artery occlusion. Concentrations of IL-6 and KC were measured in the supernatants of brain slice cultures and normalized to total protein concentrations. The graphs show the square root (SQRT) of IL-6 and KC concentrations in pg/mg at different time points in control, sham and MCAO mice. In sham mice, the cerebral release of IL-6 and KC did not differ from control mice at any time point. (A) Secretion of IL-6 from the brain tended to increase at 24 h (sham versus MCAO+vehicle: P = 0.06, data not shown) with a significant difference between sham and MCAO+vehicle 48 h after the occlusion. A slight, non-significant reduction of IL-6 release from the brain in mice treated with D-JNKI1 was seen at 5 d (MCAO+vehicle versus MCAO+D-JNKI1: P = 0.25). There was no significant difference of brain IL-6 release in D-JNKI1- and vehicle-treated mice at any time point. In MCAO + D-JNKI1 mice, IL-6 concentrations at 48 h remained significantly higher than in controls. (B) KC release in MCAO + vehicle mice started to increase significantly at 7 h compared to early time points (0 h and 4 h) and remained elevated at late time points. The brain KC release increased slightly, though not significantly, at 24 h (P = 0.19, data not shown) and 48 h (P = 0.08) after MCAO compared with sham mice. KC concentrations in MCAO + D-JNKI1 mice followed the same temporal profile as in MCAO + vehicle mice. Control mice: n = 7; sham mice: n = 5 to 8, except at 24 h, n = 3; MCAO mice: n = 6 to 10. *P <0.05 indicates a significant difference in MCAO mice and sham mice. Results are represented as mean ± SEM. When placed over a data point, ∞ and ⊗ indicate a significant difference with concentrations in the same group at 0 h and 4 h, respectively.