Influence of Tongmai Injection on N-methyl-D-aspartate Receptor 1 mRNA Expression in Cortex Neurons of Rats with Cerebral Ischemia/Reperfusion

Objective To observe the influence of Tongmai Injection(TI) on N-methyl-D-aspartate receptor 1(NMDAR1) mRNA expression of cortex neuron in rats with cerebral ischemia/reperfusion.Methods SD rats were randomized into pseudo-operation group,model group,and high-,moderate-and low-dosage TI groups(2.72,1.36 and 0.68 g · kg-1 · d-1 respectively).Rat models with cerebral ischemia/reperfusion were established by four-vessel-occlusion method.Expression of NMDAR1 mRNA in cortex neuron and the staining optical density(D) value in all of the groups were examined by in-situ hybridization.Results The number of cortex neurons with positive NMDAR1 mRNA expression and D value were increased in the model group(P0.01 or P0.001 compared with those in the pseudo-operation group).Compared with the model group,the number of cortex neurons with positive NMDAR1 mRNA expression was increased in high-and moderate-dosage TI groups(P0.01 or P0.001),and D value was reduced in high-dosage TI group(P0.01).NMDAR1 mRNA expression and D value remained unchanged in other TI groups(P0.05).Conclusion The therapeutic mechanism of TI for ischemic stroke is probably related with the inhibition of abnormal NMDAR1 mRNA expression in cortex neurons after cerebral ischemia/reperfusion,and with the reduction of neuronal injury induced by excitability neurotoxic effect.