Superoxide production by primary rat cerebral endothelial cells in response to pneumococci

Animal studies of experimental bacterial meningitis have provided evidence for an involvement of reactive oxygen species (ROS) in the pathophysiology of this disease. Using a lucigenin-enhanced chemiluminescence (CL method, w e tested whether primary rat cerebral endothelial cells can be induced to r elease ROS upon stimulation with pneumococci. In addition, we determined CS F levels of two markers of lipid peroxidation in patients with bacterial me ningitis, compared to patients with viral meningitis and noninflammatory ne urological disorders. Malondialdehyde/4-hydroxynonenal concentrations were significantly elevated in CSF samples obtained from patients with bacterial meningitis (23.12 +/- 5.47 mu M), as compared to both control groups (5.33 +/- 0.18 mu M and 7.80 +/- 0.33 mu M, respectively). Cerebromicrovascular endothelial cells, granulocytes, and the macrophage cell line RAW 764.7 (bu t not astrocytes and neuron-like cells) produced an increase in CL intensit y after stimulation with pneumococci. The peak value produced by endothelia l cells (500 +/- 83 cpm) was significantly lower than the maximum CL respon se in macrophages (1386 +/- 142 cpm; p < 0.05). After addition of superoxid e dismutase (SOD), the CL signal returned to baseline values. Equal to the CL technique, nitroblue tetrazolium (NBT) staining of RAW 264.7 showed SOD- inhibitable formazan precipitation when stimulated with pneumococci. In con clusion this study suggests an important role of endothelial cells in the p athophysiology of bacterial meningitis-namely as a source for ROS productio n (C) 1999 Elsevier Science B.V. All rights reserved.