Abstract
Cortical spreading depression (CSD) has been documented to confer ischemic tolerance on brain. Although nitric oxide (NO) is a crucial mediator in preconditioning under certain circumstances, the role of NO in CSD-induced neuroprotection is unclear. We examined the effect of L-NAME, an inhibitor of NO synthase, on CSD-induced tolerance against transient focal cerebral ischemia. A solution of 0.5 M KCl was applied for 2 h on the right hemisphere to induce CSD. Animals received either vehicle or L-NAME (4 mg/kg, iv) 30 min before CSD. Temporary occlusion (120 min) of the right middle cerebral artery was induced 4 days after preconditioning and the infarct volume was measured. Additionally, ERK 1/2 activation and cyclooxygenase-2 (COX-2) expression in the cerebral cortex were examined by Western blotting analysis immediately after cessation of CSD, or at 1, 2, 4, 8, and 24 h after CSD. CSD reduced infarct volume from 275 ± 15 mm3 (mean ± SEM) in the non-CSD group to 155 ± 14 mm3 in the CSD group (P < 0.05). L-NAME abolished this protection (281 ± 14 mm3; P < 0.05 vs. CSD group). Elevated ERK activation and COX-2 expression were observed immediately after or 8 h after preconditioning, respectively. Those responses are significantly augmented by L-NAME (3-fold for ERK and 4-fold for COX-2). These results suggest a crucial role of NO in the establishment of preconditioning with CSD.
Original language | English |
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Pages (from-to) | 84-89 |
Number of pages | 6 |
Journal | Brain Research |
Volume | 1039 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2005 Mar 28 |
Externally published | Yes |
Keywords
- Brain ischemia
- Cerebral blood flow
- Cerebral circulation
- Cerebral ischemia, transient
- Cyclooxygenase
- Ischemic preconditioning
ASJC Scopus subject areas
- Neuroscience(all)
- Molecular Biology
- Clinical Neurology
- Developmental Biology