Reduced brain edema after traumatic brain injury in mice deficient in P-selectin and intercellular adhesion molecule-1

Platelet (P-) selectin and intercellular adhesion molecule-1 (ICAM-1) media te accumulation of neutrophils in brain. How-ever, the mechanisms regulatin g neutrophil accumulation and damage after traumatic brain injury (TBI) are poorly defined. We hypothesized that mice deficient in both P-selectin and ICAM-1 (-/-) would have decreased brain neutrophil accumulation and edema, and improved functional and histopathological outcome after TBI compared w ith wild-type (+/+), In Protocol I, neutrophils and brain water content wer e quantified at 24 b after TBI, No difference in brain neutrophil accumulat ion was observed between groups; however, brain edema was decreased in dual P-selectin and ICAM-1 -/- (P < 0.05 vs. +/+ mice). In Protocol II, after T BI, tests of motor and memory function and histopathology were assessed ove r 21 days. No difference in motor or memory function or histopathological d amage was observed between +/+ and -/- mice, A role for adhesion molecules in the pathogenesis of brain edema independent of leukocyte accumulation in brain is suggested.