氯胺酮对新生大鼠海马齿状回NMDA受体亚型表达的影响

目的 观察海马齿状回N-甲基-D-天冬氨酸(N-methyl-D-aspartate,NMDA)受体亚型蛋白表达的变化.方法 生后7 d SD大鼠24只,分为2组:给药后即刻组(PND7)和给药后3周组(PND28).2组根据给药剂量不同再各分为3组(n=4),即C组:空白对照组,腹腔注射生理盐水; K1组:诱导剂量100 mg/kg,连续麻醉6 h; K2组:诱导剂量50 mg/kg, 连续麻醉6 h;维持剂量按诱导剂量的1/2追加.PND7组麻醉后24 h内处死,PND28组在相同环境中饲养3周(即生后28 d)后处死.免疫组织化学ABC法进行细胞染色.结果 在海马齿状回,PND7组中处理组NR2A、2B亚型蛋白表达均比对照组有增加的趋势(P<0.05), 但NR2C亚型变化不大.PND 28组中NR2A亚型处理组同样比对照有所增加(P<0.05),但NR2B、2C亚型变化不大.各亚型中K1、K2处理组之间均没有显著性差异(P>0.05).结论 氯胺酮对发育阶段大鼠海马的NMDA受体亚型蛋白的表达具有上调作用,进而可能对大鼠神经系统的发育产生一定影响.

Effect of ketamine in expressions of NR2A-2C receptor subunits in hippocampal dentate gyrus of neonatal rats

Objective To observe the changes of the expressions of NMDA receptor subunit proteins in the dentate gyrus hippocampus of neonatal rats after ketamine treatment. Methods Totally of 24 rats at postnatal day 7 (PND7) were equally divided into instant group (PND7) and 3 weeks post-treatment group (PND28), and each group was further divided into 3 subgroups, that is, intraperitoneal injection of normal saline (as control, Group C), intraperitoneal injection of 100 mg/kg ketamine for 6 h (Group K1), intraperitoneal injection of 50 mg/kg ketamine for 6 h (Group K2). The rats in PND7 group were killed 24 h after ketamine treatment and the rats in PND28 group were killed 3 weeks after the treatment. Immunohistochemistry was used to detect the expressions of NMDA receptor subunits in the hippocampus dentate gyrus. Results Immunohistochemical results showed that in PND7 group, ketamine resulted in elevated expressions of NR2A and NR2B in the hippocampus (P<0.05) . In PND28 group, ketamine increased the expression of NR2A subunit protein (P<0.05) , while the expressions of NR2B and NR2C remained unchanged. The dose and administration manner of ketamine seemed have no obvious effects on the expressions of NMDA subunits. Conclusion Ketamine could increase the expressions of NMDA receptor subunits in the developmental rat brain and may influence the development of the rat nervous system.