Inducible Nitric Oxide Synthase Gene Expression in Vascular Cells After Transient Focal Cerebral Ischemia

• DOI: 10.1161/01.str.27.8.1373
• Publication Date: 2011-06-17T20:08:03Z
• Authors: Costantino Iadecola; Fangyi Zhang; Robyn Casey; H. Brent Clark; M. Elizabeth Ross
• Keywords: Neocortex

Background and Purpose We investigated whether inducible nitric oxide synthase (iNOS) is expressed after transient cerebral ischemia and, if so, we sought to define the temporal profile cellular localization of expression role iNOS in mechanism ischemic brain injury. Methods The middle artery rats was occluded for 2 hours by an intraluminal filament. occurrence reperfusion confirmed laser-Doppler flowmetry (n=5). message neocortex determined reverse-transcription polymerase chain reaction. enzymatic activity assessed citrulline assay. immunohistochemistry. Results mRNA maximally postischemic at 12 not present 4 days (n=3 per time point). observed contralateral cortex. developed between 24 ( P <.05) subsided (n=4 8 immunoreactivity region restricted wall capillaries larger blood vessels hours. In regions early necrosis, inflammatory cells were positive. Treatment with inhibitor aminoguanidine (n=5; 100 mg/kg IP, BID days), starting 6 ischemia, reduced infarct size 36±7% comparison vehicle-treated controls (n=5) <.05). Conclusions Transient focal leads brain. However, spatial patterns differ from those occurring permanent ischemia: induced earlier predominantly vascular rather than neutrophils. Thus, depend on nature insult. finding that reduces adds further support hypothesis contributes damage.