No role for interleukin-18 in acute murine stroke-induced brain injury.

There is now extensive evidence to show that the cytokine interleukin-1 (IL-1) contributes directly to reversible and permanent ischemic brain damage in rodents. Because interleukin-18 (IL-18) shares many structural and functional similarities with IL-1, the authors tested the hypothesis that IL-18 contributes directly to ischemic brain damage in mice exposed to focal, reversible (15-minute or 30-minute) middle cerebral artery occlusion. IL-18 expression was not induced acutely by middle cerebral artery occlusion, and deletion of the IL-18 gene (IL-18 knockout mice) did not affect infarct volume. The present results suggest that IL-18 does not contribute to acute ischemic brain damage.