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目的:探讨谷氨酸及其 N M D A 受体是否参与牙髓伤害性刺激的传递,揭示它们与牙痛传递的内在关系.方法:随机分配为4 组的28 只大鼠.一组单纯给予穿髓刺激,另一组在穿髓刺激前预先侧脑室分别给予3 种浓度的谷氨酸 N M D A 受体拮抗剂 M K－ 801 .另设 M K－ 801 对照组和正常对照组.存活相同时间后观察各组动物延髓 FOS 蛋白的表达.结果: M K－ 801 + 穿髓组较单纯穿髓组延髓 FOS 蛋白表达量显著减少,且呈剂量依赖性.结论:谷氨酸可能参与了牙髓伤害性信息的传递过程,其中 N M D A 受体具有重要作用.“,”Aim: To assess the roles of glutamate and its NMDA(N-methyl-D-Aspartate) receptor subtype in processing noxious sensory input from dental pulp. Methods:28 rats were divided into 4 groups randomly. One group received noxious stimaulation of dental pulp from exposing pulp cavity. In another group glutamate NMDA receptor subtype antagonist, MK-801 (0.04~4nmol), was administrated into lateral cerebral ventricle prior to exposing pulp cavity. MK-801 control group and normal control group were added. Fos-positive neurons in medulla oblongata were detected by immunocytochemistry after the same survival time. Results: The numbers of Fos-positive neurons in trigeminal spinal nucleus and in the area of medullary visceral zone after noxious dental pulp stimulation were reduced dose-dependently by an administration of MK-801. Conclusions:This result suggests that dental pulp noxious sensory input to neurons at medulla oblongata depends on glutamate transmission, and NMDA receptor subtype has an important role in this processing.