Fig. 4.

Activation of the acute phase response after intracerebral injection of 1 ng IL-1β at P14 by intravenous injection of 100 ng IL-1β. (A) Liver gene expression of inflammatory cytokines and chemokines, IL-6, TNF, ICAM-1, CXCL-2 and CXCL-5 at 4 h in three different inflammatory paradigms: saline i.c. + 100 ng i.v., 1 ng i.c. + saline i.v. and 1 ng i.c. + 100 ng i.v. Data are represented as relative fold change from expression levels in the 1 ng i.c. + saline i.v. group of animals. The intravenous administration of 100 ng IL-1β significantly increased expression of pro-inflammatory cytokines within the liver in comparison to the 1 ng IL-1β intracerebral injection alone. The combined central and systemic IL-1β administration significantly reduced expression of CXCL-2 and CXCL-5 compared to systemic IL-1β alone. Neutrophil numbers in the liver of P14 mice that received an i.v. injection of 100 ng IL-1β or the combined treatment of i.v. 100 ng IL-1β and i.c. 1 ng IL-1β were significantly higher than in animals that received an i.c. injection of 1 ng IL-1β alone (B, C). The number of neutrophils found in the liver following the i.c. injection of 100 ng IL-1β alone was significantly higher than all other groups (B, C). Scale bar = 50 µm. ^*p < .05, ^**p < .01 and ^***p < .001. i.v.: intravenous, i.c.: intracerebral. saline i.c. + 100 ng i.v.: n = 3, 1 ng i.c. + saline i.v.: n = 8, 1 ng i.c./100 ng i.v.: n = 8 and 100 ng i.c.: n = 6.