Treadmill pre-training suppresses the release of glutamate resulting from cerebral ischemia in rats.

This study was designed to investigate the neuroprotective effect of treadmill pre-training against the over-release of glutamate resulting from cerebral ischemia. Sprague-Dawley rats underwent 2 weeks of treadmill run-training before cerebral ischemia was performed by middle cerebral artery occlusion. The level of glutamate in brain extracellular fluid was detected before, during and after ischemia/reperfusion. The expression of metabotropic glutamate receptor-1 (mGluR1) mRNA in striatum was examined after ischemia for 80 min and reperfusion for 240 min. Neurological defect score and brain infarction volumes were measured. The treadmill pre-training significantly suppressed the release of glutamate, and reduced the expression of mGluR1 mRNA at 59% (P < 0.01) and 62% (P < 0.05), respectively, as compared with the ischemia group. The neurological defect score and infarction volume were significantly improved by 75% (P < 0.01) and 74% (P < 0.01), respectively, in the pre-training group, as compared to the ischemia group. Treadmill pre-training has a significant neuroprotective function against ischemia/reperfusion injury, by suppressing glutamate release resulting from cerebral ischemia, and this effect may be mediated by downregulation of mGluR1.