BACKGROUND: To investigate the role of glutamate in the transient focal cerebral ischemia, a reversible middle cerebral artery occlusion model was induced in 25 male Sprague-Dawley rats. METHODS: Triphenyltetrazolium chloride (TTC) stain was used for evaluation of the changes of infarction ratio in MK-801 (0.3, 1.0, 3.0 mg/kg) or pentylenetetrazole (50 mg/kg) treated groups. RESULT: The infarction ratio at 48 hours after 2 hour transient focal brain ischemia was 39.2 +/- 13.2% in control group and 23.8 +/- 4.2, 27.0 +/- 8.9, and 12.8 +/- 4.4% in MK-801 (0.3, 1.0, 3.0 mg/kg) groups. In the pentylenetetrazole (PTZ) group, the infarction ratio was 32.6 +/- 6.7%. CONCLUSIONS: The non-specific glutamate receptor antagonist, MK-801, showed a trend toward dose-dependent improvement, but the PTZ group showed no improvement. From these results, it suggested that glutamate might be partly involved in the mechanisms of ischemia-induced neuronal damage.