Neuroprotective effect of D-(E)-2-amino-4-methyl-5-phosphono-3-pentenoic acid in the gerbil model of transient global cerebral ischemia.

Effect of the new competitive N-methyl-D-aspartate (NMDA) antagonist D-(E)-2-amino-4-methyl-5-phosphono-3-pentenoic acid (CAS 137424-81-8, CGP 40116) was examined in a mongolian gerbil model of global cerebral ischemia. Effect of CGP 40116 was compared to that of another competitive NMDA antagonist, (+/-)-cis-4-phosphonomethyl-piperadine-2-carboxylic acid (CAS 110347-85-8, CGS 19755) under the same conditions. Drugs were administered intraperitoneally 30 min before bilateral carotid artery occlusion. At 4 days after the ischemia, locomotor activity was significantly higher in ischemic control mongolian gerbils in comparison with sham-operated mongolian gerbils. CGP 40116 at the dose of 10 mg/kg and CGS 19755 at the doses of 10 and 30 mg/kg significantly suppressed the increase of the motility. Seven days after ischemia, ischemic control group was still hyperactive compared to sham-operated group. CGP 40116 at the dose of 10 mg/kg and CGS 19755 at the dose of 30 mg/kg significantly reversed it. The number of survived neurons of ischemic control group was significantly less than that of sham-operated group at 7 days after ischemia. CGP 40116 at the dose of 10 mg/kg and CGS 19755 at the dose of 30 mg/kg significantly increased the number of survived neurons. It is concluded that CGP 40116 is more potent for amelioration of global cerebral ischemic damage than CGS 19755.