Neuroglobin up-regulation after ischaemic pre-conditioning in a rat model of middle cerebral artery occlusion.

PRIMARY OBJECTIVE

Neuroglobin (NGB) is a known neuroprotector and is up-regulated after ischaemia-hypoxia brain damage. However, no studies have investigated NGB levels after ischaemic pre-conditioning and middle cerebral artery occlusion (MCAO).

METHODS AND PROCEDURES

This study subjected rats to different ischaemic pre-conditioning and MCAO regimens and assayed NGB levels in the hippocampus, cortex and hypothalamus by immunohistochemistry, quantitative polymerase chain reaction (PCR) and western blot.

MAIN OUTCOMES AND RESULTS

After 30 minutes of ischaemic pre-conditioning, the number of NGB-positive cells and NGB levels in the hippocampus, cortex and hypothalamus were increased with longer reperfusion times, peaked at 24-hours reperfusion and slightly decreased at 48-hours reperfusion. Similarly, the mRNA and protein expression levels of NGB were also up-regulated; they peaked at 24-hours reperfusion and slightly decreased at 48-hours reperfusion.

CONCLUSIONS

NGB may regulate neuroprotection against ischaemia and hypoxia-mediated brain damage after ischaemic pre-conditioning. The results provide additional evidence supporting the utility of ischaemic pre-conditioning and help elucidate its potential regulatory mechanism.