Temporal profile of cerebrospinal fluid glutamate, interleukin-6, and tumor necrosis factor-α in relation to brain edema and contusion following controlled cortical impact injury in rats

Traumatic brain injury is associated with release of the excitotoxin glutamate and production of pro-inflammatory cytokines IL-6 and tumor necrosis factor-alpha (TNF-alpha). Following controlled cortical impact injury, cerebrospinal fluid (CSF) glutamate, IL-6, and TNF-alpha concentrations were measured to investigate their relationship to evolving tissue damage. Compared to non-traumatized rats CSF glutamate, IL-6 and TNF-alpha: levels were significantly increased by 8 h after trauma (P < 0.005). Parallel to Increasing brain swelling and contusion CSF glutamate was significantly elevated over time, reaching highest levels by 48 h (33 +/- 4 mu M) while IL-6 and TNF-alpha showed maximum values at 24 h after trauma (42 +/- 7 and 4.7 +/- 1 pg/ml) (P < 0.005). The observed different temporal profile of CSF glutamate, IL-6, and TNF-alpha following focal traumatic brain injury could be of therapeutic importance. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.