ABSTRACT
Tumor necrosis factor α (TNFα) is a pleiotropic cytokine that appears to be involved in blood brain barrier, inflammatory, thrombogenic, and vascular changes associated with brain injury (for reviews see Feuerstein et al., 1994; 1995; 1996). TNFα can be expected to exert diverse effects in the brain (see Table 17.1). It increases leukocyte infiltration/activation, apparently associated with its ability to increase the expression of adhesion molecules, induce the expression of chemotactic molecules, and to disrupt the blood brain barrier as well as its action as a chemoattractant. The importance of leukocyte infiltration in the pathogenesis of brain injury has been reviewed previously (Feuerstein et al., 1996; Kochanek and Hallenbeck, 1992). TNFα can exert mixed effects and act as a growth factor to induce cell proliferation; under certain conditions it can produce cytotoxicity (see Table 17.1).
