Changes in expression of NR2B subunit-containing N-methyl-D-aspartate receptors in hippocampal neurons of rats with lidocaine-induced convulsion

Objective To evaluate the changes in the expression of NR2B subunit-containing N-methyl-D-aspartate receptors in hippocampal neurons of rats with lidocaine-induced convulsion.Methods Twenty-four male Sprague-Dawley rats,aged 6 months,weighing 220-250 g,were randomly divided into 2 groups (n =12 each):normal saline group (group N) and lidocaine group (group L).In L group,2％ lidocaine was injected via the tail vein at a rate of 4 mg· kg-1· min-1 until the animals developed convulsion (Racine Ⅲ).The equal volume of normal saline was given instead in group N.Hippocampi were isolated at 0,6 and 12 h after convulsion stopped (T1-3) to detect the expression of NR2B protein and mRNA using Western blot and RT-PCR.Results Compared with group N,NR2B protein and mRNA expression was significantly up-regulated in group L (P ＜ 0.05).NR2B protein and mRNA expression was significantly lower at T1 than at T2 and T3 in group L (P ＜ 0.05).NR2B protein expression was significantly lower at T3 than at T2 in group L (P ＜ 0.05).Conclusion The expression of NR2B subunit-containing N-methyl-D-aspartate receptors is up-regulated in hippocampal neurons of rats with lidocaine-induced convulsion,and the change may be due to convulsion induced by lidocaine. Key words: Lidocaine;  Seizures;  Receptors, N-methyl-D-aspartate ;  Hippocampus