In:
Journal of Neurosurgery, Journal of Neurosurgery Publishing Group (JNSPG), Vol. 86, No. 3 ( 1997-03), p. 493-504
Abstract:
✓ Proinflammatory cytokines mediate brain injury in experimental studies. This study was undertaken to analyze the production of proinflammatory cytokines in experimental contusion. A brain contusion causing delayed edema was mimicked experimentally in rats using a weight-drop model. Intracerebral expression of the cytokines interleukin (IL)—1β, tumor necrosis factor—α (TNFα), IL-6, and interferon-γ (IFNγ) was studied by in situ hybridization and immunohistochemistry. The animals were killed at 6 hours or 1, 2, 4, 6, 8, or 16 days postinjury. In the injured area, no messenger (m)RNA expression was seen during the first 2 days after the trauma. On Days 4 to 6 posttrauma, however, strong IL-1β, TNFα, and IL-6 mRNA expression was detected in mononuclear cells surrounding the contusion. Expression of IFNγ was not detected. Immunohistochemical double labeling confirmed the in situ hybridization results and demonstrated that mononuclear phagocytes and astrocytes produced IL-1β and that mainly astrocytes produced TNFα. The findings showed, somewhat unexpectedly, a late peak of intracerebral cytokine production in the injured area and in the contralateral corpus callosum, allowing for both local and global effects on the brain. An unexpected difference in the cellular sources of TNFα and IL-1β was detected. The cytokine pattern differs from that seen in other central nervous system inflammatory diseases and trauma models, suggesting that the intracerebral immune response is not a uniform event. The dominance of late cytokine production indicates that many cytokine effects are late events in an experimental contusion. Different pathogenic mechanisms may thus be operative at different times after brain injury.
Type of Medium:
Online Resource
ISSN:
0022-3085
DOI:
10.3171/jns.1997.86.3.0493
Language:
Unknown
Publisher:
Journal of Neurosurgery Publishing Group (JNSPG)
Publication Date:
1997
detail.hit.zdb_id:
2026156-1
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