Potential mechanisms of interleukin-1 involvement in cerebral ischaemia.

Interleukin-1 (IL-1) has pleiotropic actions in the central nervous system. During the last decade, a growing corpus of evidence has indicated an important role of this cytokine in the development of brain damage following cerebral ischaemia. The expression of IL-1 in the brain is dramatically increased during the early and chronic stage of infarction. The most direct evidence that IL-1 contributes significantly to ischaemic injury is that (1) central administration of IL-1beta exacerbates brain damage, and (2) injection or over-expression of interleukin-1 receptor antagonist, and blockade of interleukin-1beta converting enzyme activity reduce, dramatically, infarction and improve behavioural deficit. The mechanisms underlying IL-1 actions in stroke are not definitively elucidated, and it seems likely that its effects are mediated through stimulation and inhibition of wide range of pathophysiological processes.