Two peaks of interleukin-6 and keratinocyte-derived chemokine release into the plasma after middle cerebral artery occlusion. Square root-transformed (SQRT) IL-6 and KC plasma concentrations at different time points in control mice, sham and MCAO mice treated with vehicle or D-JNKI1. (A) In sham mice, IL-6 did not differ from control mice at any time point. Plasma IL-6 was induced 4 h and 7 h after MCAO+vehicle at a significantly higher level than sham mice. At 24 h (data not shown) and 48 h, IL-6 concentrations in MCAO+vehicle mice returned to basal level and increased again 5 d after the occlusion (sham versus MCAO+vehicle: P = 0.054). The plasma IL-6 concentration in MCAO+D-JNKI1 mice was slightly reduced at 4 h and 5 d but not statistically different from MCAO+vehicle mice (4 h: MCAO+vehicle versus MCAO+D-JNKI1: P = 0.26; 5 d: MCAO+vehicle versus MCAO+D-JNKI1: P = 0.27). Seven hours after MCAO, IL-6 concentration in D-JNKI1-treated mice was significantly higher compared with sham mice. (B) Plasma KC was induced early in MCAO+vehicle mice compared to sham mice and decreased from 24 h (data not shown) onwards. Five days after MCAO, KC concentration was again significantly higher than in sham mice (sham versus MCAO+vehicle: P = 0.03). KC concentration in MCAO+D-JNKI1 mice was similar to MCAO+vehicle mice, without any statistical difference between the two groups. In the sham group, KC concentrations at 4 h, 7 and 24 h (data not shown) were significantly higher than in controls. 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, **P <0.01 indicate a significant difference between MCAO and sham mice. Results are presented as mean ± SEM. When placed over a data point, ∞, ⊗ and × indicate a significant .difference with concentrations in the same group at 0 h, 4 h and 7 h, respectively.