Kinetics of polymorphonuclear neutrophil infiltration after a traumatic brain injury in rat

THE aim of our study was to assess polymorphonuclear neutrophil infiltratio n into the injured parenchyma after a traumatic brain injury (TBI). Myelope roxidase (MPO) activity was assayed on the hippocampus, temporal and pariet al cortex 6, 24, 48, 72, and 120 h post-trauma. MPO activity occurred in th ese structures from 6 h post-trauma and was maximum at 24-48 h. It was reso lved by 72 h in the hippocampus and the parietal cortex, but persisted in t he temporal cortex until 120 h after trauma. This suggests that neutrophil infiltration is a delayed phenomenon in the physiopathology of TBI. Conside ring that a large therapeutic window may be crucial in the management of TB I, inhibition of neutrophil infiltration needs to be further investigated f ollowing cerebral trauma. (C) 1999 Lippincott Williams & Wilkins.