The neuroprotective efficacy of MK-801 in focal cerebral ischemia varies with rat strain and vendor

The present study was designed to evaluate whether the neuroprotective efficacy of MK-801 in focal cerebral ischemia was dependent on strain and/or vendor differences. MK-801 (0.12 mg/kg i.v. bolus followed by 0.108 mg/kg/h infusion or 0.60 mg/kg i.v. bolus followed by 0.540 mg/kg/h infusion) or saline was administered just after intraluminal middle cerebral artery occlusion. Administration of 0.540 mg/kg/h MK-801 provided strain/line-dependent neuroprotection in the following rank order: Simonsen Laboratories Sprague-Dawley rats > Simonsen Laboratories Wistar rats > Taconic Laboratories Sprague-Dawley rats. After 0.108 mg/kg/h MK-801 treatment, Simonsen Laboratories Wistar rats were the only strain/line that were significantly neuroprotected. These results indicate that the neuroprotective effect of an experimental drug may be influenced by rat strain and vendor differences.